Saturday, July 24, 2010

Bonnie the blobette: July 24, Update A

Bonnie wasn't much to be concerned about once she got into the Gulf because of the factors I mentioned yesterday. Earlier today convection picked up a bit, but not enough to write about. Er... apart from that last sentence. ;-)

Her center is still over the Gulf, at about 28.5N, 87.6W, central pressure around 1011mb. Although officially winds are 30mph, I think it's less than that. She's moving WNW at 14mph. All tropical storm watches & warnings were cancelled earlier today.    

This is my last update on Bonnie. I'll write next when there's a blob that looks like it would enjoy being called Colin (next name).

That's all for now! Have fun my friends.
J.

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Disclaimer: Read the blog for proper disclaimer - I'm too busy having a lazy Saturday. ;-)
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Friday, July 23, 2010

Tropical Depression Bonnie: July 23, Update B

Crossing Florida just took the steam out of this wee Bonnie lass ;-).
 
She's back to being a Tropical Depression with maximum sustained winds of 35 mph and central pressure of 1009mb. There are pockets of heavy rainfall, but most of the really stong convection (thunderstorms etc) vanished once she was over land and away from the Florida Current. Wind shear has been more-or-less consistent from the south-southeast all day, so the convective activity remained north-northwest of the center.
 
She sped across the state in about 5.5 hours and is now leaving the west coast via Naples. Her current position is near 26.2N, 81.9W and she's still moving WNW at a rapid 18 mph. She has consistently remained on the northern edge of the cone with almost every advisory, which is why she's farther north than the forecast from a couple of days ago (hence avoiding the Keys). If this continues, whatever is left of her will make landfall in Alabama or possibly Florida again - along the Panhandle (just what you need Pensacola, isn't it?).
 
I don't anticipate much development over the Gulf, although the surface waters are a warm 29-30 deg C. There are a number of factors that I think will act against any further development. First, she is moving very quickly, so the time over warm water is reduced. Second, she won't be anywhere near the Loop Current <science alert... see below>, and will be mostly over the West Florida Shelf, which is a broad and shallow shelf and the warm water is not very deep. And thirdly, it looks like wind shear will increase even further. The only thing to really keep an eye on is the vorticity (circulation), which is still quite strong in the lowest part of the troposphere.
 
<Science alert> The Loop Current in the Gulf of Mexico becomes the Florida Current, which in turn becomes the Gulf Stream - kinda like a long windy road that changes name at major intersections. And before it becomes the Loop Current in the Gulf, it is the Yucatan Current in the Caribbean. Crossing any part of this long ocean current system is dicey for storms because the warm water is veerrry deep. A storm churns up water, but when it crosses these areas it churns up more warm water instead of cold water, so it has more 'fuel' and lo-and-behold, convection increases. We saw this in action today when convective activity really picked up as it crossed from the Bahamas to the south east coast of Florida. <End of science alert>.
 
Notes from the trenches: 
- Marathon (in the Keys) - this afternoon they had lovely blue skies and 5mph winds - from Gene S.
- Miami was wet, but not as bad as the stuff Puerto Rico had - from Chris M. (who is having a rather soggy moving day, but they are leaving Florida so getting hit by a weak Tropical Storm seems a fitting farewell).

And sent in from Richard S.:
    My Bonnie lies over FLO-RI-DA,
     My Bonnie lies over MEEE.
      My Bonnie lies over FLO-RI-DA,
       So send Bonnie back out to Sea!!
 
Done. :-)
 
To wrap up the blob in the western Gulf of Mexico story: it produced a lot more rain and thunder than Bonnie, but it's over land, so no blob.
 
That's all for today. 
Toodle pip!
J. 

Blog archives at http://jyotikastorms.blogspot.com/

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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 was there and was going to "run away, run away" (Monty Python), I'll let you know.
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Tropical Storm Bonnie: July 23, Update A

Quick lunchtime (my lunchtime) update via phone!

TS Bonnie has, indeed, been following a path that's been on the northern side of the cone, and is shortly going to arrive on the south east coast of Florida. She's obviously in a rush to get there and visit the NHC (in Miami) in person because she's moving at a very fast 18mph! The convection picked up as she began interacting with the Florida Current, but because of strong wind shear from the south,  most of the rain & thunder is on the northern side if the center of circulation. Free car wash for anyone in SE Florida! ;-)

Because of the shear, she's a weak system with max winds still at about 40mph (TS range: 39-73 mph) and central pressure of 1008mb.  

I know there's a lot of concern about her getting into the Gulf, but at this point it doesn't look too bad. If she'd gone over the Keys, I'd be a bit more concerned. If I recall correctly, Florida and the Gulf in general has had equally severe, if not worse, weather since the oil spill started. Of course, now I've said this I'm reminded of Tropical Storm Fay, which actually intensified as she crossed southern Florida a couple of years ago. The thing to watch out for over the next few hours is how much the convection decreases as it moves across the state.

More later. Lunch done. Back to this real work lark. Don't forget your raincoats if you live in Florida, anywhere south of Orlando! And let me know what the weather is (and if you don't want me to post your comments, let me know that too!).

Later gators! (and er... now what was that other one...?) ;-)
J.

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Disclaimer: Same as on my website, but can't cut & paste on phone. Will do it later. Pay attention to your local emergency managers, the NHC, and NWS. I just do this for a hobby! ;-)
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Thursday, July 22, 2010

Tropical Storm Bonnie: July 22, Update B

The NHC just upgraded TD3 to Tropical Storm Bonnie, based on further information from a reconnaissance aircraft. Maximum wind speeds are now 40 mph (TS range: 39-73 mph), making her only just a Tropical Storm. Central pressure is 1005mb. She's still moving in a NW direction at 14mph, and their revised center location is 22.9N, 75.4W.
 
The only other change I see is that convection is picking up slightly again, which backs the increase in wind speed.
 
Next update from me tomorrow. Really. I mean it this time. ;-)
 
Good night from this side of the pond!
J.
 
Blog archives at http://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. If I was there and was going to "run away, run away" (Monty Python), I'll let you know.
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Tropical Depression 3 & Gulf of Mexico Blob: July 22, Update A

Tropical Depression 3:
Woo hoo... we have the third Tropical Depression of the season! :-)
 
Our rainy little western Atlantic blobette got upgraded to a Tropical Depression today (one, two, three... aww! ;-)). A Tropical Depression is when the system has 'closed' circulation but winds are less than 39 mph. For this TD, maximum winds are currently 35mph and central pressure is 1006mb. A plane was out there this afternoon and found it wasn't strong enough (yet) to be a Tropical Storm (TS wind range: 39-73 mph). I'd agree with this because from the satellite images it looks like it's still struggling. Convection, although looking good earlier today, has decreased over the last few hours.
 
It's visiting the Bahamas (how nice). The NHC have the center of circulation at 22.7N, 75.4W moving NW at 14mph. I agree with the NW movement, but I might have had one too many glasses of wine because that doesn't look quite like the location of the center to me. From satellite images, I think the center is somewhere around 22.8N, 74.9W. This suggests that the forecast track may be to the right (northern edge) of the current cone, which means it's currently heading towards the east coast of Florida. BUT, the forecast from the NHC is that the pressure patterns that are steering this will change (based on models), and it will begin heading WNW tomorrow, bringing it to the southern tip of Florida, the Keys and then into the Gulf eventually - but only as a very weak Tropical Storm. Bear in mind is that this is a weak system, and it's typically harder to forecast the track of weak systems because it's difficult to find the center.
 
Wind shear died down a bit today, which is what gave this system a chance, but it looks like it might pick up again. Sea surface water temperatures are around 28-29 deg C, but temperatures warmer than 26.5 deg C don't extend very deep because the water depth is pretty shallow. I think that if this system is going to pick up any strength it will be when it's close to or over the Florida Current system, but that's a day or two away and it depends on atmospheric conditions at the time.
 
The other factor that may be contributing towards inhibiting it is Saharan Dust. It's difficult to see in the satellite images because of the all the clouds (go figure!), but there is a lot of dust blowing off Africa at the moment, and extending across the Atlantic. I got this from Gene S. today:
"I  have been in Marathon Fla (in my boat) for more than a week due to 25 mph wind out of the east. We have been having one heck of a dust storm since last Friday. visibility has been way down ..and air temp is hot and humid as the dickens.  We can smell the dust. Last Sat it was so bad in Stuart, Fla that African dust made the front page of the news paper."
 
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Gulf of Mexico Blob:
 
This rather large beasty is over the Bay of Campeche, near Mexico. Convection with this system has been very strong - poor Mexico is getting lashings of rain with a dollop of thunder and lightning! Water temperatures are over 29-30 deg C here and wind shear is weak. The circulation is as strong in the lower half of the troposphere as that in the TD, so I would have thought this was also a TD by now. It is close to Mexico, so there's a chance it will make landfall without getting to that status. 
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That's all for today folks. Oh, my cat would like to add: 'mggggreee333eeezz'. I think it means 'stop writing and give me some food before I fall asleep'. ;-)
 
Until tomorrow amigos!
J.
 
Blog archives at http://jyotikastorms.blogspot.com/

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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 was there and was going to "run away, run away" (Monty Python), I'll let you know.
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Wednesday, July 21, 2010

Western Atlantic Blobette: July 21, Update A

This blobette is having a bit of an identity crisis today and isn't looking quite so bonnie anymore. ;-) (puns always intended). As I thought, the wind shear and proximity to the islands of PR & Hispaniola took their toll and the NHC said the same thing this afternoon when they downgraded the percentage of formation from 70% to 60%.
 
The blobette still has some lower level circulation centered just north of Haiti and near the southern end of the Bahamas. But because of that wind shear, the convection is to the east and south - stretching from the Dominican Republic to the Windward Islands and including the Virgin Islands. I got this from Tom J. in St. Thomas yesterday afternoon: "we have had plenty of rain and very heavy at times...like today. had to pump down the pool level twice today. expecting more flooding rain tonight and hope the following mosquitos are gentle...there will be millions after a rain like this. this system has vollyed north and south over us since Saturday...will it ever leave??  Still pouring with plenty of lightning and thunder...4pm and it looks like 8pm at night.....weird."  I think they finally saw the sun today. For about 5 minutes anyway.
 
Although this system is all over the place, it still has some pretty good low level circulation which means there's a small chance it could re-develop if it moves away from the bigger islands of Hispaniola and Cuba - but I'm not yet convinced that will happen. Also, although water temperatures are in the 29-30 deg C range, the wind shear is still looking strong. I (along with many others) will be keeping an eye on it, just in case it does something sneaky. For now, it's still a blobette that's trying really hard to be a grown-up storm (or at least a Tropical Depression!).
 
Until tomorrow!
Toodles,
J.
 
Blog archives at http://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. If I was there and was going to "run away, run away" (Monty Python), I'll let you know.
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Tuesday, July 20, 2010

Western Atlantic Blobette: July 20, Update A

Another bonnie attempt at forming Tropical Storm Bonnie is in the works right now. (I spent entire *seconds* thinking of that sentence - does it show? ;-))

This blobette is just north of Puerto Rico (PR) and appeared on my radar over the weekend. It brought some wellie-wearing weather to the Virgin Islands on Sunday - "our man on the ground", Tom J., in St. Thomas said they had horizontal rain on Sunday and it looks like they are still getting squally weather - third day in a row! Hope you have extra rain gear!

Waay back then it didn't really have much circulation, but that was a whole two days ago. It's really picked up since then and, in addition to the convection (heavy rain and thunderstorms) it now has some pretty good circulation (vorticity) in the lowest levels of the troposphere.

It's a bit too soon to say, but I'm not sure if this will become a big storm. It is certainly over waters warm enough to sustain a storm (surface temperatures are 28-30 deg C) and waters of 26.5 deg C+ can be found in the upper 50-75 m of the ocean. But it is close to the PR and Hispaniola islands and there is some pretty decent wind shear to the northern edge of this blobette, both factors which will slow down development. As usual, how much this develops very much depends on the track. If it stays over water then there's every chance of it getting stronger.

About the track. The NHC says it's moving WNW at 10mph and will do so for the next day or so. I'd agree with that. The good news is that it will be closer to Hispaniola, which will inhibit development. The bad news is that I expect Haiti will get a lot of rain, which usually results in landslides and they don't need that.

This is one to keep an eye on - there's a small chance it may end up in the eastern Gulf. Next update when something interesting happens (to the blobette... not to me!). ;-)

Ciao,
J.

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To New Readers: I'm sorry. Are you sure you don't want to watch reality tv instead? There's probably a really good one out there about watching grass grow or something. No? Well, I hope you've been suitably warned. If you have any questions about my fancy-schmancy scientific terminology (oo-aaah :-) ) or anything else about storms or whatever else I mention, please let me know. I like reading your questions ... and sometimes I've even been known to answer them! ;-)

Blog archives at http://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. If I was there and was going to "run away, run away" (Monty Python), I'll let you know.
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Sunday, July 04, 2010

Caribbean Blobette: July 4, Update A

Happy 4th of July! As a special treat for you a blobette has been developing in the Caribbean. Isn't that nice? ;-) ('Blobette': my "technical term" for a collection of clouds and thunderstorms that may develop into a (she-name) tropical storm.)

I mention it because it's in the same area that the blob-that-became-Alex really began to kick up a fuss and there is some decent circulation in the lower half of the troposphere (lowest level of our atmosphere, more details here: http://jyotikastorms.blogspot.com/2010/06/caribbean-blob-june-25-update.html). At this location the water temperature is over 29 deg C, with a very deep layer of warm water (greater than 26.5 deg C) in the upper 100-125m of the Caribbean Sea. Tropical storms need water warmer than 26.5 deg C to develop, so ocean conditions are certainly ripe for further development. There is a little bit of wind shear in the atmosphere, which I think is the only thing keeping this as a blobette for now. It's moving WNW at about 15mph, towards the Yucatan Peninsula region.

I'll be keeping an eye on this one. The next name is Bonnie. Another update only if this blobette develops further.

An appropriate quote for today is by Abraham Lincoln:
"we, your forefathers, were brought forth upon a most excellent adventure conceived by our new friends, Bill... and Ted. These two great gentlemen are dedicated to a proposition which was true in my time, just as it's true today. Be excellent to each other. And... PARTY ON, DUDES!"
(from the classic documentary, 'Bill & Ted's Excellent Adventure' ;-) ).

Have fun!
J.

Blog archives at http://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. If I "run away, run away" (Monty Python), I'll let you know.
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Thursday, July 01, 2010

Tropical Storm Alex: July 1, Update A

Great googliemooglies! That'll teach me to go galavanting around during hurricane seasaon and neglect the storm. Alex sneakily went up to a cat 2 just before landfall, with a beautiful eye and everything. Boys. Huh. They never behave! ;-) (you know I'll say the opposite later in the season, don't you?)

Alex is now back down to being a Tropical Storm, but I agree with the NHC that he was a cat 2 with a central pressure of 947mb at landfall in Mexico around 9pm CDT yesterday evening. According to the NHC, his winds were 105 mph, making him a pretty decent strength cat 2 (cat 2 range: 96-110mph).

He is currently over central Mexico, somewhere around 22.4N, 102W, moving WSW at around 13mph. The minimum pressure is now at least 990mb, and rising, and winds are barely Tropical Storm force at 40mph (TS range: 39-73mph). Despite the low wind speed he has quite a bit of convection, and for a storm that's so far inland he still has A Lot of circulation in the atmosphere (which is interesting in a "hmm... that's interesting" sort of way).

Next time I decide to be away from a computer for a few days, I'll make sure Mother Nature knows so she can form another storm. This is my last entry on Alex... unless he makes the crossing into the Pacific! (highly unlikely, but he IS a bit stubborn).

Until next time, ciao for now! :-)
J.

Blog archives at http://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. If I "run away, run away" (Monty Python), I'll let you know.
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