Jyotika's Tropical Storms Blog

Wednesday, September 12, 2007

[Jyo_hurricane] Tropical Storm Humberto & Tropical Depression #8: September 12, Update B

TS Humberto:

The storm that is in the Gulf off the northern Texas coast just got
upgraded to Tropical Storm Humberto (not wanting to be a storm with no
name, he zipped through the Tropical Depression phase in ~three hours -
after I sent out the last update). He is interacting with land, and
landfall will be overnight in northern Texas or near the TX/LA border -
it's not very easy to pinpoint the center of circulation. He is moving
northwards and will continue in that general direction because he is on
the western edge of a high pressure system (which will be mentioned
again in the TD#8 discussion).

He's about 70 miles south-southwest of Galveston and is moving north at
6mph. He is over very warm water with sea surface temperatures greater
than 30 deg C. Max. winds are near 45 mph (39kt; TS: 39-73mph, 34-63kt)
so he is a weak system but he does have a lot of moisture, so this will
be mostly a rain event for TX,LA, and possibly states farther inland.
He's in some moderate wind shear, and is also interacting with land, so
there is not much opportunity for him to get much bigger.

A plane will be in the system shortly, so I will send out another update
after the NHC has issued it's 5pm (eastern time) advisory.

And because this is mid-September there's another system swirling away
out there in the Atlantic.

Tropical Depression 8:

This system is also moving along the edge of that high pressure system I
mentioned above. I used this analogy last year, but as I can barely
remember what I said last week, who will remember this from then? :)
Imagine the high pressure in the Atlantic as a clock face - a Dali clock
which is all distorted but still has a 12, 3, 6, and 9. These storms all
move in a clockwise direction around this distorted clock. The trick is
that the clock face (high pressure) never stays still and the edges are
constantly moving as well, so forecasting a storm track is really all
about how the pressure patterns change.

At the moment TD#8 is on the southern side at around 6 and heading
westward(ish), and TS Humberto is at around 9 and heading northward.

TD#8 will continue in a general westward (clockwise) direction around
this high until it can turn north-westward or until it hits land. H.
Dean and H. Felix both hit land before turning because the high extended
quite far south-westward. It is not as robust now, however at the moment
it looks like the general westward direction will continue for the next
few days. The models all have it staying in the Atlantic but to me it
looks like it will enter the Caribbean in about ~4 to 5 days. I'll know
more tomorrow when I get the latest pressure maps.

It is about to enter a region of low wind shear and the temperatures are
at about 27 degs C (enough to sustain a system). The center of
circulation is east of the convection, which is also helping to keep
this system down (in intensity).

More later....
J.

-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] The Blob and the bigger Blob: September 12, Update A

The Blob:
A 1958 movie which introduced Steve McQueen to the movie-going audience.
It was the only time he was listed as Steven McQueen. It made more money
than anyone expected and is considered a classic these days. Oh sorry...
wrong Blob blurb :)

O.k., there's a Blob (my technical term as you know for what is more
officially known as an 'invest' or 'Low'). It is hanging off the
Texas/LA coast (and those in TX will already know this because it's
probably raining or will rain... yet again). This morning it looked like
there was some circulation to it, but that is no longer obvious and from
what I see, it is just a mass of heavy convective activity. The NHC will
send a plane to investigate it early this afternoon so it might get
bumped up to a formal Tropical Depression. It is already interacting
with land.

The bigger Blob:
The Blob movie was remade in 1988. I didn't see that one, but I'm sure
it was riveting (?!?)

This is actually a nice looking system with circulation and convection
at about 13-14N, 45W in the Atlantic. This has far more promise in terms
of developing further. If the storm in the Gulf is not named, then this
is the most likely candidate to become Humberto.

I'll send out another update later today on both of these systems.

Have fun in the sun (unless you live in Texas). :)
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Monday, September 10, 2007

[Jyo_hurricane] Tropical Depression Gabrielle: September 10, Update A

Although she's been downgraded, this storm has aged gracefully and looks
better today than she has done in the past few days. She is in the
Atlantic now and heading in a northeastward direction. There's still
some nice circulation, but not much convection. What there is remains on
her southern side which is over the northern edge of the Gulf Stream.
It's unlikely that she will get any stronger so this is my last post on
this storm (probably ;)).

I'm also keeping an eye on the blob in the Gulf (which doesn't look like
it will develop into anything), and the blob in the tropical Atlantic
(~10N, 34W) which holds more promise but is in a region of strong wind
shear at the moment. More when something develops.

Enjoy the weather. :)
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Sunday, September 09, 2007

[Jyo_hurricane] Tropical Storm Gabrielle: September 9, Update B

TS Gabrielle made landfall (Cape Lookout National Seashore) as a
weak-to-mid Tropical Storm at about 11.45 am, with no change in max winds
(50mph). The heaviest convective activity has so far has remained
off-shore, and it looks like she is weakening. She is heading in a north
almost north-northeastward direction, and has picked up her forward speed
to 12mph. Soon she will be heading in a northeastward direction and away
from the US as she moves clockwise around that high pressure system over
the Atlantic.

Her intensity didn't change today because of the combined effects of wind
shear and some limited interaction with land. The wind shear has been
strong enough to push the center of convection to the south of the center,
and the center of circulation is again visible on satellite images. So,
although she hasn't completely cleared NC yet, she looks like she will be
a 'nice' storm for them. I hear they are in a drought, but I am not sure
this storm brought them enough rain to help that situation.

Once she re-emerges into the Atlantic later today her center will be close
to the northern edge of the Gulf Stream, which skirts the US coast from
Florida to Cape Hatteras, NC and then 'breaks away' from the coastline and
heads out in a north-eastward direction into the Atlantic. Depending on
how close she is to the Gulf Stream, this means that Gabrielle will be
over cooler waters of somewhere between 25-27 degs C. Along with the wind
shear from the north, this should stop her from developing any further.

Just a point of interest: North Carolina has historically had the most
'hits' and I don't mean number 1 chart topping hits (although they may
have had those too) :)

And now it's time for a cup of tea :)
More tomorrow.
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Tropical Storm Gabrielle: September 9, Update A

Good morning,

Yesterday we were looking at an exposed center of circulation and
convection in the north-west quadrant. The convection was in that quadrant
because that was the part that was over the warmest waters and the Gulf
Stream. Last night, the center of circulation moved a bit more westward,
bringing it in line with the area of convection, and she truely became a
tropical storm.

Overnight it looks like she oscillated in intensity - weakened, and is now
strengthening again. The main part of the storm is still sitting just
off-shore and parts of NC have, so far, only had a few small patches of
bad weather. A small wobble in the path will be enough to bring her
on-shore versus just clipping the NC coast.

She is moving very slowly (around 9-10mph) in a north-northwestward
direction, over the Gulf Stream. The longer she stays over the Gulf
Stream, the more intense and bigger in size she can get. There is some
wind shear, so that should help keep the intensity down but there's a
chance she will become a mid-to-strong TS before she moves off into the
Atlantic if she doesn't hurry up and move forward soon.

Max. sustained winds are now about 50mph (TS: 39-73mph), making her a
weak-to-mid TS. They will probably increase further because of the warm
water beneath the center. The actual center of circulation is harder for
me to see from the satellite images today, but according to the hurricane
planes it is at 34.2N, 76.4W (30 miles south-southeast of Cape Lookout).

We'll obviously know more in a few hours. More later...
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Saturday, September 08, 2007

[Jyo_hurricane] Tropical Storm Gabrielle: September 8, Update B

I was waiting to see what the NHC would say in their 5pm advisory before
sending out another update. They have changed ST Gabrielle's status from a
STS to a Tropical Storm. But she is weaker - they downgraded the max.
sustained winds to 40mph (TS: 39-73mph), so she is just barely a TS. In
case you didn't get this from my morning entry, I am not at all suprised
at her official weakened status. :)

I would have gone a step further and just downgraded her to a Tropical
Depression. Their reasoning is that there is a small chance she will get a
bit stronger (from barely a TS to a weak TS) this evening, so they didn't
want to downgrade her completely. I won't argue with that reasoning.

Since this morning's email, Gabrielle has steadily been declining and has
lost a large portion of what little convection she did have, making her
even less of a storm. The northern "rain band" pretty much disintigrated
and is just cloudy now. You can clearly see the center by the wispy
looking clouds that are circling it in satellite images e.g.
http://www.ssd.noaa.gov/goes/flt/t3/vis.jpg
There is still some convection in the northwest quadrant of the system,
the rest is all clouds and a windy day at sea. However, the convection in
the northwest quadrant will probably reach coastal areas of NC once the
storm moves a bit farther north.

She did slow down and is now moving forward at 8mph.

Also, after I sent the last message, they have been shifting the track
away from the coast a bit. Again, I agree with this shift. She is
currently heading northwestward.

By staying away from the coast, it means that she will be moving over
cooler waters sooner - she is already in slightly cooler waters of 27-28
degs C. There is also a chance for less interaction with the Gulf Stream
depending on her path. On top of that, the wind shear will be better than
expected. All these will keep this system down.

A number of people have told me today that so long as a named storm is
this weak they don't mind. The reason I object to naming this (and two
others earlier this year) is because, alas, there are those who just look
at the total number of named storms per season. For example, insurance
companies. The more named storms there are, regardless of strength, the
worse the season looks to those who just look at the numbers and not at
each storm. I could be mistaken of course. Maybe insurance companies do
look at each storm in detail? In which case, they would so far have a
tally of 4 named storms this year that truely deserved it, not 7.

If she looks like she's really picking up intensity and/or heading to the
NC coast, I'll send out another update later. Otherwise you'll hear from
me tomorrow.

Toodle pip,
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Subtropical Storm Gabrielle: September 8, Update A

I got out of bed this morning for this "storm"??

Here's another very pathetic looking storm, which by some definitions of a
Tropical Storm (or Subtropical Storm) should not yet be named. Yes, there
are winds in a closed circulation that exceed 39mph (there's been a closed
circulation with decent winds in this system for at least 2 days) - the
winds are about 45 mph, so it's a very weak storm (TS winds: 39mph-73mph).
BUT there is very little convection, and what there is is all to the
north. One definition of Tropical Storm that I read says: "Convection
usually concentrated near the center with outer rainfall organizing into
distinct bands."

Convection concentrated near the center? I suppose it depends on your
defnition of 'near'. And if there are organized distinct bands of rainfall
in Gabrielle at the moment, then I need a new job.

O.k. Saturday morning rant over :) We will accept this as the
third-pathetic-named-storm-of-the-season-which-would-not-have-been-named-a-few-years-ago.
Bringing our total number of named storms up to 7.

Sub-tropical Storm Gabrielle is moving at a slow 12 mph in a
west-northwestward direction. The reason she is slower than some of the
other storms this year is because she is surrounded by higher pressure, so
it's a bit of an uphill battle. There is a good chance that she will slow
down even more. Interestingly, the pressure in her 'center' is at
1011mb...which is not very low at all (normal range of pressure on average
over Florida during the year varies from about 1013mb to 1020mb).

I am not sure yet that she will make landfall - it will depend on the
pressure and also on how much she slows down. If she does make landfall,
just south of Cape Hatteras/Cape Hatteras is the most likely area - which
is in agreeement with the NHC. But, there's a good chance that she will
just barely clip those areas with her "outer rain bands" and stay mostly
in the Atlantic.

She is over warm waters of 28-29 deg C, but as she gets closer the land
that will increase to 29-30 degs C. Also, she is heading into an area of
reduced wind shear closer to land. So, maybe she will become a bit better
organized later (which is when I will consider her a proper storm). Of
course, if she slows down and hangs out over the deep warm waters of the
Gulf Stream (she's not quite there yet) then she will improve in
intensity.

Despite my cavalier attitude towards this system, of course for those of
you in North Carolina be prepared for some breezy weather with possible
rain/thunder/lightning just in case. I'm sure you are anyway. :)

I'll send another update later.

Ciao for now,
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Tuesday, September 04, 2007

[Jyo_hurricane] Tropical Storm Felix: September 4, Update A

I just got back to planet Earth and see that Felix made landfall in
Nicaragua earlier today as a cat 5 storm. He is now a tropical storm and
about to enter Honduras. Of course, the danger really at this point is
from landslides due to heavy rainfall.

Some people asked me if Atlantic basin storms can cross into the Pacific,
and if they can do they keep the same name. Yes, they can cross and
redevelop but they are given different names once they are in the Pacific.
There are at least two cases in the past 20 years that I know about:

In 1996, Hurricane Cesar hit southern Nicaragua as a low level hurricane
and crossed central America and reintensified in the eastern Pacific as
Hurricane Douglas.

In 1988, Hurricane Joan also hit southern/central Nicaragua as a strong
hurricane (cat 4), crossed central America and reintensified in the
Pacific to become Tropical Storm Miriam.

The track that Felix took is a little farther north than Cesar or Joan so
it is unlikely that he will survive the transition as he moves westward
because there is more mountainous land in his path than there was in the
other two cases.

This is my last entry on this storm.

Cheerio for now.
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Monday, September 03, 2007

[Jyo_hurricane] Hurricane Felix: September 3, Update A

Felix (wasn't that the name of one of the odd couple?) is still an
impressive storm, with winds of 135mph - a cat 4.

He did become a cat 5 last night as he crossed that patch of deep warm
water I mentioned yesterday. He is currently over less deep warm water,
but I expect him to regain cat 5 status in a few hours because the water
is, again, deep and warm ahead of him. However, I am not sure he will make
landfall as a cat 5. I think there's a good chance he will be a cat 4 at
landfall (in Nicaragua/Honduras) because just before landfall, the warm
water is very shallow and he will be interacting with land. Still a very
impressive storm and not good for the areas in his path.

At the moment hurricane force winds extend out to 30 miles from the center
and tropical storm force winds are being felt 115 miles away. From the
latest satellite images it looks like he is expanding in size so these
distances may be too small. The outer bands are already over land.

The high to his north is still holding strong and keeping him to the
south, so I agree still with the NHC track. He is moving along at a brisk
20 mph, and is expected to make landfall in less than 24 hours.

I won't be able to send another entry until after landfall, but I'll send
one out after assessing the post-landfall.

Toodles,
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Sunday, September 02, 2007

[Jyo_hurricane] Hurricane Felix: September 2, Update A

This planet that I'm on doesn't seem to provide me with easy access to
email. Or the news. It's quite a nice stress-free planet really... but
apparently I must be partial to some stress because here I am, on the
internet.

O.k., when I said a couple of days ago that this storm wasn't going to do
anything much for a couple of days, I had in my head that he would become
a low-to-moderate sized hurricane today. But Hurricane Felix has been a
very bad boy. In less than 24 hours, he has gone from a cat 1 (74-95 mph
winds) to a CAT 4!! (131-155 mph). This is one of the fastest developing
storms I can remember and the NHC estimate a pressure drop of 3.4 mb/hour.
I have to admit though, he is a very handsome looking storm with a really
nice eye.

He is currently at 13.8N, 72.5W, moving at 20mph (fast). Winds are near
140mph, but they only extend out at hurricane force to 25 miles at the
moment. Tropical storm force winds are out to 115 miles from the eye. I
agree with the track for the next few days - the high to the north is
keeping it south, and at the moment it looks like landfall in the Yucatan
Peninsula. Possibly Belieze.

The bad news (there's good news??!) is that he is now moving to even
warmer waters of 29 deg C or higher, and even worse, he will soon be
passing over an area in which the warm waters are very very deep. The wind
shear will not keep this down, and there is very little interaction with
land now that he is in the Caribbean. So, it looks like he will become a
cat 5 storm.

I will try and check in sometime in the next 24 hours, but overall, I
agree with the NHC official track. Landfall won't be for 2-3 days yet.

More sooner or later...
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Friday, August 31, 2007

[Jyo_hurricane] Tropical Depression 6: August 31, Update A

Well we almost made it into September before I sent you another little note.

The future TS Felix is in the vicinity of the windward islands at the
moment. It is still a pretty weak system, and it was after the NHC sent a
plane in to investigate that they upgraded it from the 'invest' to a
tropical depression.

It's at about 12.5N, 60W, so over the southern windward islands, and is
moving at a nice pace at 16 mph. There is low-to-moderate wind shear ahead
of the storm - at least until it reaches the middle of the Caribbean in a
couple of days. The two competing effects for development I think are
actually the warm temperatures of the water in the Caribbean (29-30 deg
C), which will help in to intensify the system, and the South American and
mass which is interacting with the southern edge of the storm. It will
probably be TS Felix by tomorrow.

There is still a high pressure to the north, which is steering the system
to the west-northwest, and therefore I agree with the official path for
the next couple of days. After that, the path is less certain (way to
state the obvious here!), but at the moment I would agree with the
official path that keeps in heading towards the Yucatan (again, alas).

I am currently on a different planet at the moment (i.e. taking a break :)
) so I'll only be checking in once in a while. But I don't expect too much
change for a couple of days anyway.

Enjoy the weekend!
Ciao,
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Wednesday, August 22, 2007

[Jyo_hurricane] Hurricane Dean: August 22, Update A

It is done. Hurricane Dean made landfall in Mexico (again) about an hour
ago (12.30pm EST). At 11am he was upgraded to a cat 2, and made
landfall as weak cat 2 with winds of 100 mph/87 kt (cat 2: 96-110mph,
83-95 kt). Phew.

It looks like the wind shear, land interaction, and no warm water with
depth was enough to keep the intensity low - the official forecast
yesterday just after he left the Yucatan was for a cat 3 at landfall.

The lowest pressure for Dean was 906 mb, and that was at the Yucatan
landfall. That's the third lowest Atlantic hurricane pressure at
landfall. Hurricane Gilbert (1988) hit Cancun as a cat 5 with 900 mb at
landfall (although it dropped to 888 mb during it's lifetime), and the
1935 Labor Day Hurricane that hit the Florida Keys had ~892 mb at
landfall. The lowest overall pressure for an Atlantic Hurricane was
Hurricane Wilma in 2005, with a low of 882 mb when it was in the middle
of the Caribbean (before it got near to the Yucatan).

I suspect they will be retiring the name 'Dean' from the list at the end
of the year. Hmmm... yet another parallel with the Dean I know... ;)

Switching gear: the mass north of Haiti now is still not doing anything
much. Those of us in Florida will probably get some rain from it in a
day or two, but it isn't a system of any description so don't worry
about it. Related to this...

There's a new term (jargon) in town: 'Invest' (at least it is new to me
this year - maybe I was just living in blissful ignorance in previous
years). Anyway, this new NHC designation is for areas of convection that
may or may not turn into something, but that they are 'investing' some
time in monitoring. I don't mind what they call them, but it seems that
some computer modelers out there must be really bored because yesterday
someone showed me a computer 'spaghetti plot' for this latest 'Invest' -
it's not even designated as a Tropical Depression!!! and it doesn't even
look like it will amount to anything more than some squally weather. I
think the reason this particular area of convection was been brought to
my attention a number of times in the last couple of days is because
these spaghetti model plots were available on the web. It is a bit much
really. There is no need to get that concerned over these 'invests'.
They should at least wait until it is a good TD before posting potential
tracks.

Well folks, that's all from me until the next one - I'm hoping that
won't be until mid-September (of next year? - ever the optimist) at
least! Or unless I have something else to say (of course).

Enjoy the empty in-box. :)
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Tuesday, August 21, 2007

[Jyo_hurricane] Hurricane Dean: August 21, Update A

As you may have heard, Hurricane Dean hit the Costa Maya (Majahual) area
of the Yucatan Peninsula as a Category 5 (165 mph sustained winds) storm
this morning. Fortunately the worst of the H. Dean winds seem to have
been in a sparsely populated area. I'm sure we'll get a better idea of
the damage tonight and tomorrow. A cat 5 landfall is quite an infrequent
occurrence because the storms usually get downgraded prior to landfall
as they begin to interact with land. The last time an Atlantic hurricane
made landfall as a cat 5 was in 1992 - Hurricane Andrew (which was
initially thought to be a cat 4 direct hit, but got upgraded afterwards).

Hurricane Dean has emerged from the Yucatan Peninsula and is now in the
Bay of Campeche as a mid-sized cat 1 storm with winds of about 80-85 mph
(70-74 kt) (Cat 1: 74-95 mph, 64-82 kt). He is a lot more disorganized
than earlier today (thank goodness), especially on the northern side of
the storm, and is going to be crossing waters of ~28-31 deg C but they
are just warm near the surface, not with depth. At the most he might
regain a weak-to-mid cat 2 status before landfall again near the Tampico
region (Mexico). This 2nd Mexican landfall will be in less than 24 hours
unless he slows down, but even then, the track is unlikely to change
much. I agree with the forecast track. As for his intensity, he is
heading into a region of moderate wind shear, and now that he is weaker
it might have some impact. Also, the southern side of the storm will
continue to interact with land (poor Mexico!) so that should also slow
down intensification. We'll know in the next few hours how strong the
relative effects of the atmosphere, land and sea surface temperature
were on this storm.

It is all relative isn't it? A few days ago a cat 2 at the next landfall
would have been big news (and I'm sure it is to those who are in its
path), but after the rare cat 5 at landfall we saw this morning, its a
relief that he will 'only' be a cat 1 or cat 2 hurricane!

The convection in the Atlantic (north of Puerto Rico now) that I
mentioned yesterday continues to show very little sign of development,
but those who do this professionally are watching it like a hawk...I'm
just watching it like a er... humming bird :) ... and there's not enough
yet for me to get concerned about. I mention this because a few people
have asked me about it again today.

I don't see anything else out there right now either.

Ciao for now,
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Monday, August 20, 2007

[Jyo_hurricane] Hurricane Dean: August 20, Update A

I thought I'd wait today to see if H. Dean got upgraded to a cat 5. He is
very close with sustained winds just below 155 mph - the cat 5 boundary.
His central pressure is down to 915mb, as recorded by a plane.

I agree completely with the track depicted by the central line of the
cone. Unless there's a wobble, actual eye landfall should be just north of
Belize, but hurricane force winds extend out to 60 miles and they will
feel those. The path across the Yucatan Peninsula and the Gulf on the
other also looks good.

H. Dean might not reach cat 5 before landfall tonight because it has
started to interact with land which might be enough to counter the
extremely warm waters (one can hope, right?). If he does, it will be for a
very short time. Either way, the winds are enormous, and if the forward
speed of 20 mph is maintained, he will have crossed the peninsula in a few
hours (maybe 6). This won't be enough to knock all the steam out of such a
powerful system, and he might still be in the cat 1 or 2 range on the
other side. In the Gulf, the surface temperatures are warm, but the waters
along the track he will take are not warm with depth, so he won't
intensify too much.

Quite a few folks have asked me yesterday and today about the two areas of
convection just north and east of the Leeward Islands. The mass to the
north (~22N, 60W) has dwindled during the day. The mass a bit farther
south (~14N, 60W) is still there and but is not organized. There is a
little bit of circulation, but not enough to call it a tropical
depression. No need to worry about either of these yet.

More tomorrow.
J.

P.S. I don't know why the August 19th blog entry is not on the blog
website. But I didn't have much to say yesterday anyway (for a change :)),
so if you are reading these from there you didn't miss much.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Sunday, August 19, 2007

[Jyo_hurricane] Hurricane Dean: August 19, Update A

Not much change in my track or intensity forecast. The official center of
the cone has moved southward and I agree more with this than the one they
had yesterday. The only tweak I would make is that I think it will pass a
little bit closer to Grand Cayman (~19.2N, 81.4W) than it looks like - but
it is all within the cone, so it's not a big change. I agree with the area
of landfall over the Yucatan Peninsula - south of Cozumel, north of
Belize.

Hurricane Dean is still barreling (18mph) west-northwestward as a
mid-to-strong cat 4 with winds of 145 mph. Hurricane force winds extend
out to 60 miles. The eye should still either clip Jamaica or pass very
very close to it to the south in about 12 hours.

There's really not much more to add to this that I didn't say yesterday.
It's still relatively quiet in the Atlantic.

Toodles for now,
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Saturday, August 18, 2007

[Jyo_hurricane] Hurricane Dean: August 18, Update A

I *knew* Hurricane Dean would be a nuisance! but he is a good-looking
storm at the moment with a nice eye and circulation. He is a very strong
Cat 4, with winds of 150 mph (130 kt) (cat 4: 131-155 mph; 114-135 kt)
and a central pressure of 929mb. An earlier plane reconnaissance
detected a minimum pressure of 924 mb earlier this morning but the NHC
didn't upgrade H. Dean to a cat 5 because the other data they received
from instruments dropped into the storm did not corroborate what the
flight level winds were showing. Hurricane force winds extend out 60
miles from the center, and tropical storm winds are out to 205 miles.

Track:
I was wrong yesterday when I said that the storm is no longer being
impacted by the low that was over the Bahamas. It is. The low has slowly
been moving westward and southward, and is currently sitting over
Florida. The low will continue to move westward and southward over the
Gulf of Mexico, and H. Dean should continue to follow it. The current
forecast track has the center of the cone going over Jamaica (as a cat
4) and then the Cayman Islands (as a cat 5). Assuming the storm
maintains it's current speed of 17 mph (which is slower than it was
before, but still quite fast), I agree with the track portion that
includes a direct hit or very close call for Jamaica and the Cayman
islands. By Monday evening though, I think it will be a little more
south (by at least a degree) than the center line is indicating - but
still within the cone. If that's the case, then it will go quite solidly
over the Yucatan Peninsula, and if it survives that, then it will
continue westward to Mexico. Having said this, I'm not a professional
forecaster with computer models or the latest/bestest plots - I'm just
working out the trajectory using trigonometry and a pencil and paper
(and you thought trig wouldn't be useful in 'real' life!) - so for those
in southern Texas, I reckon you should keep to your plans on getting
ready and boarding up your place in the next few days (landfall on that
coast, if it survives the Yucatan, should be on Weds/Thurs). I'll do
another track calculation later in the day or tomorrow.

Intensity:
So, if that is the path this storm will take, what about the intensity?
This is where things get really interesting (depending on your point of
view of course, and as a geeky scientist-type, I think it is fascinating
:) ).
The atmosphere: the wind shear over the central Caribbean (around
Jamaica) is back and is pretty good, but the storm itself will modify
the wind field (because it is powerful), so although the shear might
have some impact, it won't be enough to knock it down by much.
The land: the storm will interact with Haiti, but I don't think the eye
will pass over Haiti at this point, so it won't be enough to knock it
down by a lot either. However, the shear and the limited land
interaction should both help a bit.
The ocean: this is the really naughty player in this game. As I said
yesterday, after the storm crosses about 70W, the water is not only warm
at the surface (29-30 deg C), but it is warm with depth in the western
Caribbean (much more so than the eastern). As the storm churns up water
from below the surface, instead of churning up colder water (and
therefore reducing it's own fuel supply), it will be churning up warm
water - it's like an all-you-can-eat buffet for the storm!
Unfortunately, the warm water is deepest right around Jamaica.

It will be a battle between the forces for good and evil. As it
approaches Jamaica, Hurricane Dean might experience a reduction in
intensity from it's current very strong cat 4 to a very strong cat 3 or
weaker cat 4, but in either case it is going to do some damage. After
Jamaica, at the moment it looks like the wind shear decreases, the ocean
is still v. bad, and there is less interaction with land as it
approaches the Caymans. So we can expect intensification again.

All of the above is based on a forward speed of 17 mph and a consistent
speed/direction movement in that low that it is following. If either of
these change speed (or direction in the case of the low), then the track
and intensity will probably change.

I heard from St. Thomas - they had some wind, no rain. All well in that
part of the world. I still don't see anything in the Atlantic behind H.
Dean - there are some areas with circulation but no convection, and
there are some areas of convection with no circulation. This is what
we've been seeing in the Atlantic so far this season before H. Dean came
along.

More later.
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Hurricane Dean: August 17, Update D

This is like the stock market week I believe - it's just going from bad to
worse.

Hurricane Dean is now a Category 4 storm and has slowed down to a forward
speed at a stately 18 mph (which is still a lot faster than other storms
I've seen). But he has slowed down over that lovely (!) warm ocean and in
a region of low wind shear.

The slowing down is in response to the high pressure being in his path as
I mentioned earlier. But he has also taken a more westward path, which is
also in response to that high pressure. He might even move a little
southward because that's the only way to get around the high without
slowing down too much (stalling is really really bad). If he maintains
this westward track overnight, then it looks like the high is strong
enough to keep him to the south, in which case landfall is more likely to
be in central America. If he resumes his west-northwestward track, then
the high is not as strong and it means that Jamaica, the Yucatan, and
somewhere on the Gulf (western/northern) will be affected. I think that at
this point the low that was over the Bahamas has stopped it's influence on
H. Dean, so the chance that it would go over DR/Haiti/Cuba is unlikely.

The minimum pressure is 937 mb and the maximum sustained winds are 145 mph
(126 kt). This makes him a mid-strength cat 4 (cat 4: 131-155mph; 114-135
kt). He is currently at about 15N, 66W. From an oceanic point of view, it
almost doesn't matter what his track his, once he has crossed 70W, he will
intensify further (if he doesn't before). At that point, although he will
be over approximately the same temperature waters, he will be over water
that is warm with depth. I'll go into that another day (maybe tomorrow),
but for now, it seems likely that he will reach cat 5 status by this time
tomorrow unless there is something in the atmosphere to hold him back.
This would be ahead of the official forecast, which doesn't have him as a
cat 5 until Monday. I hope the official intensity is the right one!

More tomorrow (did you think you'd get a day off?)
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast. If I "run away,
run away" (Monty Python), I'll let you know.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Friday, August 17, 2007

[Jyo_hurricane] Hurricane Dean: August 17, Update C

Well, the good news is that there isn't anything following Hurricane
Dean in the Atlantic at the moment (as far as I can see).

The bad news is really er... not so good :). He is a mid-to-strong cat
3 with sustained winds of 125 mph (109 kt) (cat 3: 111-130mph;
96-113kt). He is slowly slowing, and is now moving forward at (still
rapid) 21 mph. The min pressure is 961 mb and although a plane has
already been in the system once today, they will be sending another in
later today. What would we do without these planes (and when can I go up
in one)? The eye is at about 15N, 64.5W. He's over water temperatures of
around 29 deg C, in a region of low wind shear, and not interacting much
with land. All conducive to an increase in intensity.

This means that there is still nothing to stop him intensifying further.
It looks like that low I mentioned yesterday (was it only yesterday?) is
pulling him a bit more northwards but I don't know how much longer that
will have an impact. There is no good scenario at this point. The best
scenario would be that his track is even more north than the current
one, taking him over or very close to DR/Haiti and Cuba (eye within 30
miles) - and the only reason that is a good track is because it would
keep the intensity down a bit. The wind shear that I also mentioned
yesterday is weakening so I don't know how much that will impact this
storm (alas).

The only consolation in this is that currently the hurricane force winds
are confined to a small area, extending 30 miles from the center -
really small relative to the area that tropical storm winds are being
felt (out to 185 miles). There is a lot of rain across this system
though. To see the extent of the wind field from the center of the
storm, go to the nhc web page (www.nhc.noaa.gov) and click on the top
set of graphs in the Hurricane Dean box (one shows hurricane wind speed
probability, the next is the 50 kt wind speed and the third is the
tropical storm force winds). Then you can see who might be in a
particular wind field.

It is still too early to say what will happen after the next 24 hours.
Until that point, I agree with the official forecast, but beyond that I
am not so sure of the track (and therefore the intensity). It seems that
the models are also thinking along different lines after the next ~24
hours regarding the track (I think they agree on the intensity). The
GFDL model (a really good model - and I'm not just saying that because
there is someone who reads this who works on that), is predicting
landfall in Louisiana, whereas the UKMET (for example; another good
model in my unbiased opinion) is predicting landfall over Mexico but
barely clipping the Yucatan Peninsula, and NOGAPS is predicting landfall
closer to Belize. This is a good test to see which model is doing well
this year. I can see all of these as still being good possibilities
(I'll try and be less wishy washy in 24-36 hours :) ). Even out to three
days the models have some tracks going north of Jamaica and others going
south - these two tracks will result in different intensities, so the
tracks are really quite important.

I have to reiterate what the NHC is saying at this point: everyone in
the Caribbean and Gulf states should keep an eye on this storm (you can
use your other eye to do other things).

Ciao for now...
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Hurricane Dean: August 17, Update B

I knew I shouldn't have said anything about not sending out another note
today.

Hurricane Dean has just be upgraded to a Category 3, and a mid-sized one
at that. I will send out another update in a few hours.

More later,
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Hurricane Dean: August 17, Update A

Hurricane Dean is just about a cat 2 at the moment after crossing the
islands (14.4N, 61.7W). He will regroup and regain some strength because
he will be going over warm water and will be in an area of relatively
low wind shear for now but it's unlikely that he'll get above a cat 2
today - and so I agree with the official forecast. The wind shear in the
central Caribbean is still there, and may still play a good role in the
intensity of this storm.

The high pressure to his north has intensified and is extending farther
south into the Caribbean. This can result in one of two things: he will
take a southward path or he will slow down. The official forecast calls
for him to slow down from his current 23 mph forward speed. If you
think of the high pressure as a hill that the storm is trying to skirt
around, so if the high 'moves' in front of the storm, the storm has to
either change its direction in response, or slow down because it is
going 'up-hill'.

At the moment, it seems unlikely to me that the low over the Bahamas is
going to be big enough to interact with Dean.

Unless there's a significant change in the track or intensity today,
I'll be back tomorrow.
Have a lovely day!
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Thursday, August 16, 2007

[Jyo_hurricane] Hurricane Dean: August 16, Update C

Hurricane Dean is now a Cat 2 and will be in the Caribbean tomorrow. He's
at ~14N, 59W, and is moving forward at a brisk 25 mph. The bad news is
that the water temperatures will increase from the current 28-29 deg C to
29-30 deg C once he has crossed the islands and the wind shear will still
be weak. The good news is that he might weaken a little bit in crossing
the islands - probably not enough to knock him from his lofty cat 2 status
though.

Earlier today I was hoping that the low that was over the Bahamas region
would have intensified enough to change his path. It is still a little too
soon to tell because he's too far away, so the track is still the same for
now - west-northwest.

But there is some good news. The wind shear in the central Caribbean has
gradually increased in the past 24 hours. The higher shear region is still
at least 2 days away from the storm and the it could weaken again but, at
the moment, it is in the current forecast path of the storm and if it
persists it could weaken the storm or at least stop it intensifying.
That's still a couple of days away.

For those with interests in the US Virgin Island area, the latest report I
got from there was at about 6pm this evening. The winds were 7-10 mph, and
it was still a clear day (thanks TJ :) ).

What an 'interesting' day. Luckily for you, I think that's all I have to
say for now.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Hurricane Dean: August 16, Update B

Oh dear, this is going to be an multiple-update day I see.

According to the satellite wind estimates, and also a NOAA buoy, the
hurricane center thinks the winds in Dean are now somewhere in the
89-92mph (77-80 kt) range, and possibly higher. This makes Dean a strong
cat 1 (cat 1: 74-95 mph; 64-82 kt), and almost a cat 2 (96-110mph; 83-95
kt). He is still heading in the west-northwestward direction, and if
those numbers are correct, there is no reason for him not to be a cat 2
before entering the Caribbean. The NHC will be sending a plane into the
storm later today and we'll know more after that.

Regarding the forecast track: the current forecast has him over the
Yucatan in about 5 days. Assuming the atmosphere doesn't change, from an
ocean point of view this is the 2nd worst possible track I could draw
for him in terms of allowing him to intensify. The center of the storm
does not go over any land, but does go over some very warm water, and
some very deep warm water. The worst possible track at the moment is
more-or-less the forecast track, but he goes through the Yucatan
Straits instead of over the peninsula. Having said that, I am not ruling
out the possibility that he will actually take a more northerly track
once he's entered the Caribbean because there has been a 'point of
weakness' in the high pressure (that has so far been responsible for his
westward path): there has been a low over the Bahamas area for the past
couple of days. The question is, is it still there and how much of the
high has it eroded (is it enough to divert the storm?). I am waiting for
the latest maps. My ideal scenario at this point is that he does take a
more northerly track once he enters the Caribbean, for two reasons. He
will interact more with Haiti/DR and/or Cuba which will keep the
intensity low, but he will also not be passing over the really deep warm
water, which will also help in keeping a low intensity.

My handy hint for today is for my friends going on a week-long Caribbean
cruise starting this weekend: don't forget your motion sickness pills
(you can carry the extra supply in lieu of sunscreen). :)

More later.
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] Hurricane Dean: August 16, Update A

Just a short note for now:

Dean (the storm, not the person I know by that name :)) is now a
Hurricane (although Dean the person could be too...). He's a weak cat 1
with sustained winds of 80 mph (~70 kt) (cat 1: 74-95 mph; 64-82 kt) and
is moving at a fairly fast rate of 24 mph in a west-northwest direction.
He is at about 13.5N and 53.3W. Those on the islands already have
hurricane watches and warnings in place. Stay safe.

I will send more out on this later.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Wednesday, August 15, 2007

[Jyo_hurricane] Tropical Storm Dean: August 15, Update C

Sorry about the delay in the update for this storm. TS Dean is still a
tropical storm, and he's getting stronger. We will soon start to see the
next step in his development. I agree with the official forecast some
point tomorrow he will be a cat 1 - there's an eye. The two main reasons
for this are that he will begin traversing warmer waters - of 28-29 degs
C, and he will also be in a region of lower wind shear. With no land to
inhibit his growth, there is nothing that will really stop him growing to
a cat 1.

How much beyond that he grows is still up in the air (all puns always
intentional) ;) The media are talking about the latest forecast worst case
scenario of a cat 4 in the northwestern Caribbean in about 5 days - and
that is fine because their job is to make sure people are prepared for the
worst. That may occur, but it is one of many many possibilities because
his path is still uncertain.

He is moving westward, after moving in a west-northwestward direction
earlier today and is now at about 13N, 49W. The long-term path of this
storm is still questionable, but I agree that he will stay on this general
westward track for at least another day.

That's all for now folks.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] TS Erin & TS Dean: August 15, Update B

TS Erin:
TD 5 was upgraded this morning and has maximum sustained winds near
40mph (~35 knots) (TS: 39-73 mph, 34-63 kt) with higher gusts. A
hurricane plane went into the system this morning and found the center
of circulation - most of the convection is to the north and east of this
center, and some of the early bands are already over land. It is not
very well organized, and will remain a relatively small tropical storm.
There's really not much more to add about this that I didn't say this
earlier. At landfall it is forecast to have ~50 mph (~45kt) winds - it
is unlikely to be more than that. It will bring rain however and should
make landfall in the early hours of tomorrow morning. Unless there is a
major change, this will be my last entry on this system unless someone
asks for more information.

TS Dean:
I'm going to wait for a bit before sending out an update on this system.
I'll have more to say about it then... after I've boarded up my windows.
JOKE.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] TS Dean & TD 5: August 15, Update A

TD 5:

I'm going to start with TD5 because that is closest to land. I've been
watching this system for days and days and days... it's been like
watching grass grow. But it decided to make a move, and got 'upgraded'
to TD 5 last night. It appears to me that the center of circulation is
to the south of the region of convection, and it also looks like it's
heading into a region of slightly more wind shear (as it approaches the
coast). It is over warm water, but it is not anywhere near the Loop
Current, which would otherwise have provided it with warm water from
beneath the ocean surface as well. It is not a very well formed system
at all. I agree with the forecast track - somewhere in the southern
Texas/Mexico region. *If * this does develop, it will be yet another
very weak Tropical Storm this year. Regardless of whether or not it is a
'named storm' (ooh aaah), there won't be that much wind associated with
this system but in keeping with this year's weather theme for Texas - it
will bring rain. There's a lot of water vapor in and around this system.
I'm sure they'll be pleased about that. Get your brollys and wellies out
(as we call them in the UK: US translation: Umbrellas and err... rain
boots?) :)

TS Dean:

This little guy on the other hand may eventually prove to be a bit more
of a nuisance. It all depends on the path he takes in life. There is
still some wind shear affecting him, coming out of the northeast, so the
bulk of the convection is still to the southwest of the circulation but
the wind shear is decreasing. There is dry air to the north and west of
this system. The convective activity is a little better defined around a
broad area which would be the center, although it is still difficult to
pinpoint the exact center of circulation. As for the ocean, it is over
water temperatures of about 27-28 deg C, and it will remain over these
water temperatures for at least another day. Given these conditions, I
don't see this storm developing too much today at least. The high
pressure is still firmly in place and at the moment, I think the system
will stay on it's westward track for longer than the NHC guidance shows
(they show a steady northward drift - not turn - starting today). I'll
have a better map after 10.30am, so I'll comment again on this later today.

More Later.
J.

(This and previous posts are available at

http://www.jyotikastorms.blogspot.com)

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Tuesday, August 14, 2007

[Jyo_hurricane] Tropical Storm Dean: August 14, Update B

Woohoo... let the fun begin. Now this is what I would consider the real
start to the season (o.k. so T.S. Barry was here on June 1 and wasn't a
bad little storm either).

TD4 was officially upgraded to TS Dean. The NHC have shifted his
location slightly farther south - I agree with this move. This also
means that the forecast track has shifted southwards, and for now I also
agree more with this track than their previous track. I still don't
expect this storm to intensify too much more today, and he's not
forecast to reach hurricane strength for a few days yet which sounds
reasonable to me. The convection is still to the west (and also to the
south) of the circulation because there is still some wind shear, and
there hasn't been any change in the water temperature he is moving over.

The high pressure system I mentioned yesterday is still in place, which
is keeping the storm on its westward track (and actually was why it
moved a bit farther south) - he will stay on this westward track (maybe
moving a little north or south from time to time) for the next few days.
It's too soon to say how strong he will get or where he will go - the
intensity will depend on the track, and that depends on what point the
high pressure erodes. At the moment, we wait and see.

One thing I want to point out is that the sea surface temperatures in
the Atlantic and the Caribbean are currently near or below average for
this time of year than the long term average. This is a good thing and
should help to keep these storms somewhat subdued.

I'll send another update out tomorrow unless there's a big change in
anything. Have a nice day. :)
J.
(This and previous posts are available at

http://www.jyotikastorms.blogspot.com)

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

[Jyo_hurricane] TD 4: August 14, Update A

TD 4 is still just a Tropical Depression, and I don't see it changing
too much today, although the official forecast calls for it to become a
TS today (it called for it to become a TS yesterday too, which seemed
unlikely because of the wind shear). I believe it would be TS Dean next.

It is still in a region of decent wind shear, the water temperature is
around 27 degs C. It is difficult to pinpoint the exact center of
rotation because it is not a well formed storm, but I think that the
center might be south of the track currently indicated by the NHC. The
main convection is still to the east of the center of rotation. On its
current path I don't see it getting over warmer temperatures for at
least another day (and maybe two) - unless it moves southward. The
clouds tops have become warmer in the past couple of hours which is
typical of a weaker storm, but is probably a cycle the storm is going
through. If you look at the color Infra-red satellite image (e.g.

http://www.ssd.noaa.gov/goes/east/catl/avn-l.jpg) the colors will
indicate how high the cloud tops are. Red is colder and blue is warmer
(of course! ;) )

What is the significance of warmer cloud tops?
The atmosphere is divided into layers, and each layer is defined by the
temperature. In the layer closest to the earth (called the troposphere)
the temperature gets colder the higher up you go. In the next layer up
(the stratosphere) the temperature gets warmer the higher up you go, the
layer above that it gets colder and so on. The lowest layer (the
troposphere) extends from the earth's surface to between approximately
8-16km in altitude (generally speaking, 8km is near the polar regions,
16km is near the equatorial regions). Because of the large amounts of
convection associated with tropical storms, the clouds extend up in the
troposphere. The higher up in the troposphere the cloud tops are, the
colder they will be. A really strong tropical storm (hurricane) has
cloud tops that can extend to the tropopause (the boundary between the
troposphere and stratosphere).

More later,
J.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Monday, August 13, 2007

[Jyo_hurricane] TD 4: August 13

Tropical Depression 4:

The wave that came off Africa a few days ago has now been officially
classified as Tropical Depression 4 and is in the vicinity of 12N, 30W.
It looks to me as though the center of circulation is to the east of the
region of convection (because of easterly winds - winds blowing from the
east), which has been the case since it left the African coast. This
will hamper the development of this system, despite it being over water
temperatures of 27-28 degs. In a couple of days it will be over warmer
water and in an area of lower wind shear. It has a large portion of the
Atlantic to cross yet so there is a chance that this one might intensify
to a Tropical Storm (or Hurricane eventually) - in that I agree with the
NHC forecast. There has been at least one storm this year that barely
made it to TS status and I would not have been so quick to name it, but
it's not my decision. Ho hum.

TD4 is moving in a general westward direction along the lower edge of a
region of high pressure. As a reminder: in the northern hemisphere,
these storms move in a clockwise direction around high pressure systems.
At the moment, the high pressure extends over the Windward Islands, PR,
Cuba, FL, all the way westward... it even covers Texas ;). According to
the models, they see that the pressure will erode in a few days, and the
storm will take that bend, moving in a more north-westerly direction.
This is a likely scenario, but I can't yet tell how far westward the
storm will go before bending. You'll be hearing more from me about this
one.

As I have your attention (maybe?), there is also some convective
activity off the northern tip of Cuba. It is heading into the Gulf, but
as with TD4, it looks like the center of circulation is not in the same
place and the rainfall. I'm keeping an eye on this one too.

P.S. If you have a storm related question or I use jargon you aren't
familiar with it, please send me a note and I will clarify in a
subsequent message.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Thursday, August 02, 2007

[Jyo_hurricane] Wave in Caribbean

Just a quick follow up from yesterday's entry. There is still some
circulation in this wave and it is over warm water, but it is now in a
region of increased wind shear and is almost completely surrounded by dry
air. If it manages to cross the Caribbean intact and/or looks like
developing into a tropical storm, I'll send out another message. For now
it is just a bunch (another technical term ;) ) of rainy weather.

J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not
the opinion of any organization I represent. If you are making an
evacuation decision, please heed your local emergency management and the
National Hurricane Center's official forecast and the National Weather
Service announcements. This is not an official forecast.
-------------------------------------------

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Wednesday, August 01, 2007

[Jyo_hurricane] Wave in Atlantic at ~13N, 56W. August 1.

I don't normally send out something unless the system is at least a
tropical depression or tropical storm, but after a number of replies to
the entry on TS Chantal asking about this wave, here is a short report.
This is mostly for those in the US Virgin Islands, Windward Islands etc
and those with connections down there at the moment.

This wave has been struggling to develop for many days now, but there is
some rotation with the convective activity - more than yesterday. Also
since yesterday, this system started to take a slightly more
north-westward path. It is over warm water, greater than 28 degs. and
will remain over warm water as it moves forward. The wind shear is
slight at the moment, but it is heading into a region of increasing
shear. One thing that is keeping it at bay is that it is in a region
with a lot of dry air to the north and northwest. Actually in general,
there has been a lot of dry air over the North Atlantic this year, and
although there are waves with a lot of circulation they just haven't
been able to develop.

The National Hurricane Center might send a plane in to investigate later
today if it looks like developing. Even if it doesn't develop any
further, it looks like it will bring some much needed rain to the VI in
a couple of days.

I'll send out another blurb (technical term :) ) if things change.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Tuesday, July 31, 2007

[Jyo_hurricane] TS Chantal: July 31

Well that was a nice few weeks off, wasn't it? And now there's a little
blip on the horizon. A very little blip.

There's really not much to say about this Tropical Storm. This system
has been brewing for a few days, and finally reached Tropical Storm
winds (defined as winds between 34-63 knots, 39-73 mph) this morning.
The maximum wind speed at the moment is 43 kt (50 mph) so she's not a
very strong storm. She is out in the Atlantic (~40 N, 63W), and moving
in a north-eastward direction away from the US. She is still over waters
with temperatures warm enough to sustain as storm (over 26 degs C), but
will soon be moving over cooler waters. I agree with the official
forecast that she will merge with a low front and just keep heading
towards northern Europe as a large low pressure system.

I'm not going to post anything else on this storm unless anything changes.

_______________________________________________
Jyo_Hurricane mailing list
Jyo_Hurricane@marine.usf.edu
http://seas.marine.usf.edu/mailman/listinfo/jyo_hurricane

Saturday, June 02, 2007

TS Barry: June 2

Well he's here... the heaviest(and final) rain 'bands' are over and
approaching Pinellas County (where I live). TS Barry will have made
landfall within the next 3-5 hours, in the vicinity of Tampa Bay. It's
raining pretty heavily here right now (I'm quite enjoying it :) ) and the
rain is all ahead of the center of circulation.

This is what I'd call a good storm for Florida - just mostly rain. The
only thing to watch out for is local flooding (Shore Acres area for
example), and maybe some tornadoes. The official forecast is calling for
3-5 feet above. At the moment St. Pete is between 1-2 ft above, and I
think Clearwater is closer to 2ft.

If you don't already know about this, you can look at the water levels at
tidesonline.nos.noaa.gov. On the left, click on 'state maps', then on
whatever state you are in, and then the locations shown. The blue is the
predicted - including the normal high/low tides. The red are the
observations, and the green is how high the water is above the predicted
value.

Have a lovely day everyone. I'll probably not send out another email until
the next storm.

Be careful. Watch your local reports (news/weather) for more information.

Friday, June 01, 2007

Tropical Storm Barry: June 1

Well this is a fine start to this season! That pesky low pressure system
has mutated during the day and has just been declared a Tropical Storm.
The NHC sent in a plane this afternoon and they came back with a central
pressure of 1000mb.

There's a Tropical Storm warning for the west coast of Florida from
Bonita Beach to Keaton Beach (including Tampa Bay), and a TS watch from
Keaton Beach to St. Marks to the north.

TS Barry is a weak system, with max. winds of 45 mph. He's moving north
and is currently over water of over 26 degs C and will remain over those
until tomorrow, before heading into slightly cooler waters. He is also
in a region of high wind shear. I still don't see any circulation higher
up in the atmosphere (not even at mid-levels of 5km) - another indicator
that it should remain a weak system.

It looks like this afternoon the thunderstorm activity flared up closer
to the center, along with stronger winds. So they have changed the
classification from subtropical to tropical - and you all know about
that now.

All the rainfall is ahead of the system. At the moment it looks like a
lovely day in England to me :)

I'll send out another update tomorrow or later today if it looks like
it's developing further.

The 'Official' Start of the Hurricane Season: June 1

Hey!... why didn't anyone tell me that today was the first official day of the Hurricane Season? ;) Really, unless you've been living in a tree or under a rock, there's very little chance that you wouldn't know this by now.

What's out there:
There is low pressure system which has associated with it a mass of water vapor, clouds, thunderstorms etc covering the western Caribbean-eastern Gulf of Mexico region right now. I agree with all the official forecasts, it's unlikely to develop into anything much. Cuba is getting a lot of rain at the moment, and Florida is overcast and will be getting rain today and tomorrow, and possibly even some on Sunday. Good thing too... it might put out some of the fires we have going on in this state.

A quick overview of storm systems:
So, as nothing much is going on out there, I'm going to take this opportunity to answer a question (as best I can) that quite a few of you asked me when Subtropical Storm Andrea was out there in May - What is the difference between an extratropical storm, a tropical storm, and a subtropical storm?

An Extratropical Storm: These usually form in the extratropics (quelle suprise!) and have cold air at their core. A cold air mass meets a warm air mass, and as the warm air rises (because it is lighter than the cold air), it releases potential energy that results in these systems. Because warm air rises, a low pressure is formed which is why these are also called low pressure systems.They are usually associated with fronts which are depicted on weather maps as lines of blue triangles (for a cold front) or red semi-circles (for a warm front). Because it's the collision of air masses, these systems can occur over land or water, and occur frequently in the winter in the US as snowstorms/blizzards or Nor'easters.

A Tropical Storm: These usually form in the tropics (aren't we good at naming things?) and have warm air at their core. The energy source for these differ from extratropical storms. These storms form over water only and the energy source is latent heat. Warm water evaporates into the air. As the rising warm moisture-laden air in the center reaches colder altitudes in the atmosphere, the water vapor condenses to form clouds and latent heat is released. The heaviest rains and winds are in a band close to the center. No fronts are associated with these storms (although 'waves' in the atmosphere are) - which makes it difficult to determine too far ahead of time when a storm will develop. A tropical storm is when the winds are greater than 34 knots (39 miles per hour). If the winds are less than that, it is a tropical depression.

A Subtropical Storm: These usually contain some characteristics of both extratropical and tropical systems. For example, imagine an extratropical storm moving over warmer water. Now the storm begins to get some energy from latent heat as well, and the cold air in the center (near the surface) is replaced by warm air, so the storm core can change from cold to warm. The heaviest rains and winds are not near the center. Like a tropical system, a subtropical storm is when the winds are greater than 34 knots (39 miles per hour). If the winds are less than that, it is a subtropical depression. Subtropical Storm Andrea was formed from an extratropical low pressure system/front that moved eastward off the coast of the US over warmer waters.

It's only since 2002 that subtropical storms were given names from the hurricane name list - which would partly account for why we have had more named storms in the past few years.

That's all for now. Enjoy the rain if you live in Florida. Enjoy whatever weather you have if you live in a different state :)
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast.
-------------------------------------------

Thursday, May 10, 2007

Subtropical depression Andrea: May 10

Subtropical depression Andrea is not doing so well, and I'd agree with
all the official advisories.

She is embedded in an area of high pressure, which always makes the
forecasting a bit more difficult, and explains why she is just drifting
along. When a low pressure system encounters high pressure, it's like a
ball trying to roll up-hill - not easy to do. She is still surrounded
by dry air on almost all sides, she is now in a region of higher wind
shear from the west-northwest, the water temperatures are still too
cool, and she is interacting with land on the western side. So not much
to keep her growing.

Although she is a weak storm the forecast for the next few days is
complicated. Unless she dissipates, which is very possible given the bad
atmospheric environment and the proximity to land, her southward drift
takes her over warmer waters. To complicate this some more, there is a
low front that was over Nevada/Colorado yesterday, and has reached Texas
today and is moving in this direction. So, if Andrea stays intact the
models are predicting that this front would move the storm eastward in a
few days, and I can see that as a possibility as well. It all depends on
how well she hangs together in the next couple of days.

That's all for now on this storm unless something 'interesting' happens.
Hopefully you won't hear from me again for a couple of months - wouldn't
that be nice? :)
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------

Wednesday, May 09, 2007

Subtropical Storm Andrea: May 9, Update B

It's officially the first named storm of the year.

Andrea is still moving slowly westward, but a high pressure to the west
suggests that she will make landfall probably somewhere along northeast
Florida. She is not a big storm with winds around 45 mph (TS winds:
39-73 mph). The system is moving very slowly (3mph) so there is time
for a bit of intensification as it continues to interact with the Gulf
Stream, but not enough to make a hurricane because it is already
interacting with land.
J.
-------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------

Subtropical storm: May 9, Update A

Good morning,

Our potential first named storm of the season is still loitering
mischievously off the S. Carolina/Georgia/Florida coast. All you
surfers... time to pop over to the east coast of Florida.

The NHC sent a reconnaissance plane in to investigate this morning. I
suspect they will give this one a name later today. It has wind speeds
in the lower end of the Tropical Storm range (34-63kt, 39-73mph), it has
a broad, not well-formed eye, and a pretty good circulation. In the
atmosphere, the wind shear is low, which is favorable for the storm.
However, it is almost completely surrounded by dry air, which is not so
favorable. In the ocean, it is hanging out over water temperatures of
about 24-25 degs C, which is lower than those needed for storm formation
(generally 26.5 deg C and above are the temperatures to keep an eye out
for - all puns always intended :) ). It has begun to interact with land,
which will also keep it from developing.

So... the question is that given all the conditions that would prevent a
storm from developing, why has this persisted? One reason is that it is
very slow moving and has basically remained over the Gulf Stream for
most of it's life. Although the surface waters of the Gulf Stream are
warmer than surrounding waters, the important factor is that the water
is warm here with depth as well, so the water that is being churned up
from beneath the surface of the ocean is as warm as the surface, not
colder as you might expect. The persistence (and weak strength) of this
storm has very little to do with actual surface temperatures and global
warming, and in that respect it is like many storms we have seen over
the past few years, and will probably see again this year. Another
reason is that it was formed as part of a frontal system in the
atmosphere, so it had a lot of energy (and water vapor) associated with
it to begin with as it developed into a non-tropical low pressure system.

I'll send out another note once I hear they have named it (or not).
Toodles,
J.

Tuesday, May 08, 2007

Subtropical Storm

Hello everyone... I'm back from hibernation. I know I know, 'Hurricane
Season' doesn't officially start for another few weeks, but mother
nature never listens to us. There is a reason for this email - see
below. For those of you who have joined this list over the past few
months, welcome. If at any point you want to be removed, just send me an
email. For those who have been with me for the last 3 years, welcome
back :) As usual, if you have any questions, please drop me a line.

-------------------------------
As the first email of the upcoming 'exciting'?!? hurricane season 2007,
I'm going to put my disclaimer up front:

DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
-------------------------------------------
And we're off:

Some of you have seen what appears to be a tropical storm off the
Florida/Georgia/Carolina coast (thanks to those who sent me an email
asking about it). There is, indeed, a low pressure system that has the
characteristics of a subtropical storm off the Carolina coast. The low
pressure is associated with a dying cold front (also connected to the
tornadoes in Kansas late last week). It is not unheard of that a
subtropical storm can develop into a tropical storm (TS), for example,
TS Ana in April 2003. Also, since 2002, subtropical storms have been
given names from the hurricane name list.

The atmospheric conditions look good for storm development - good
circulation and low wind shear at the moment. Winds in the storm are
Gale Force, which is 34-40 knots, or 39-46 miles per hour (mph).
Tropical Storm winds are 34-63 knots, so it's on the lower end of the
scale. It is pulling in dry air from the west and south, and the ocean
conditions are not too favorable at the moment. As your local weather
stations are probably reporting, it does mean some bad weather for the
Carolina's, Georgia and possibly Florida in a day or so. The movement of
the system is to the west. At the moment, this hasn't been officially
classified as the first Tropical Storm of the season, but I will send
out an email if the National Hurricane Center (NHC) decide to change
that status. As I was writing this, the NHC has issued a special
tropical disturbance statement, so everyone is watching this system. I'm
sure we will all hear a lot more about this in the news.

More later,
J.

testing for 2007

Ramping up for a new season - here's a test post.

Thursday, November 30, 2006

Last Day of the 2006 Hurricane Season

My final forecast... there will be no tropical storms for the rest of
the 2006 hurricane season. Today is officially the last day of a
wonderfully quiet hurricane season. So, have a good and safe holiday/New
Year/early spring ... and I'll be back sometime next year with more
riveting (!) and fun (!!) hurricane discussions.
Ciao,
Jyotika
P.S. As we are in El Nino conditions, generally Florida can expect a
rainy winter, the western US is already experiencing above average
rainfall (and will continue to do so) & the Northeastern US will be
warmer than usual this winter.

Monday, October 02, 2006

Tropical Storm Isaac: October 2, Update A

As expected, Isaac is now a Tropical Storm with winds of about 60mph.
He's moving along at a rather brisk 41mph- to provide some context,
that's faster than me on a bike.

He has merged with that low front. The convection is ahead (to the
northeast) of the center which is completely in dry air. So Newfoundland
is probably experiencing some bad weather today but things should be
better by tomorrow morning even though the center of circulation won't
reach there until tomorrow.

This is my last post on Isaac.
J.
------------------------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
------------------------------------------------------

Sunday, October 01, 2006

Hurricane Isaac: October 1, Update A

Isaac has picked up forward speed (now moving at a decent 17mph) and he
is also moving in a more northerly direction, and will turn north-north
east in the next few hours.

He's a weak cat 1 at 80 mph (cat 1: 74-95mph), and I don't expect him to
get any stronger - if anything, he should start weakening soon because
he is in colder waters now and in that region of stronger shear I
mentioned yesterday. He will probably be a tropical storm by this time
tomorrow.

There's a chance that he will clip Canada, but it won't be anything
major by the time he gets there. Nothing as strong as some of the winter
storms they experience every year.

That's all to say about Isaac for now. Toodles.
J.
------------------------------------------------------
DISCLAIMER:
These remarks are just what I think/see regarding tropical storms (my
storm blog). If you are making an evacuation decision, please heed your
local emergency management and the National Hurricane Center's official
forecast. This is not an official forecast.
------------------------------------------------------

Wednesday, September 12, 2007

Monday, September 10, 2007

Sunday, September 09, 2007

Saturday, September 08, 2007

Tuesday, September 04, 2007

Monday, September 03, 2007

Sunday, September 02, 2007

Friday, August 31, 2007

Wednesday, August 22, 2007

Tuesday, August 21, 2007

Monday, August 20, 2007

Sunday, August 19, 2007

Saturday, August 18, 2007

Friday, August 17, 2007

Thursday, August 16, 2007

Wednesday, August 15, 2007

Tuesday, August 14, 2007

Monday, August 13, 2007

Thursday, August 02, 2007

Wednesday, August 01, 2007

Tuesday, July 31, 2007

Saturday, June 02, 2007

Friday, June 01, 2007

Thursday, May 10, 2007

Wednesday, May 09, 2007

Tuesday, May 08, 2007

Thursday, November 30, 2006

Monday, October 02, 2006

Sunday, October 01, 2006

Search This Blog

Twitter Updates

Blog Archive

Subscribe To

Translate

Total Pageviews