[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.

-------------------------------
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.
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[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.

-------------------------------
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.
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[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.

-------------------------------
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.
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[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.
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[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.
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[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.

-------------------------------
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.
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[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.
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[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.

-------------------------------
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.
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[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.

-------------------------------
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.
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[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.

-------------------------------
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.
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[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.

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.
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[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.

-------------------------------
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.
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[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.

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.
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[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.

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.
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[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.

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.
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[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)

-------------------------------
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.
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[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)

-------------------------------
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.
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[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.

-------------------------------
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.
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[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.

J.

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.

-------------------------------
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.
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[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.
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[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.

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.
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