Monday, September 06, 2010

Tropical Storm Hermine & Gaston, the Atlantic Blob: September 6, Update A

Tropical Storm Hermine:
Our Gulf of Mexico Blobette was officially upgraded to a Tropical Depression late last night, and then to a Tropical Storm in the early hours of this morning. She's about to make landfall in Mexico, just south of the Texas border. Normally, as you know, I would be saying something (i.e. ranting ;-)) about short-lived storms and a wasted name, but in this case she really is a Tropical Storm. It's just fortunate that she developed so close to the coast. Her center is at 24.5N, 97W and she's moving NNW at 15mph. This little beauty had a lot of convection in her (decreasing at the moment) - lots of rain over Mexico and Texas. You can see both the center of circulation and the rainfall on the NWS radar at Brownsville (http://radar.weather.gov/ridge/radar.php?rid=bro&product=N0R&overlay=11101111&loop=no). Click on the word 'loop' on the left, next to Composite or Base, under Short Range Images.
 
Central pressure is 992mb with winds of 60mph, making her a mid-sized Tropical Storm (range: 39-73mph). Despite low wind shear I don't think she'll intensify too much more because she's interacting with land. She doesn't have any circulation (vorticity) in the upper troposphere, which also suggests she doesn't have enough structure to become a hurricane.
 
Gaston, the Atlantic Blob:
He's still driving under the influence of dry and dusty air, which isn't advisable if you have plans to become a Tropical Storm again. ;-) Wind shear is low and he has good circulation in the lowest half of the troposphere, but convection is minimal. He's somewhere in the region of 17.5N, 58.5W and is moving westward towards the northern Leeward Islands at 15-20mph. It looks like the air over the northern Caribbean (say Hispaniola and west) has more water vapor, so if he survives for the next couple of days and remains away from land, there's a good chance he'll re-form. You can see 'Gaston, the blob' on the Meteo France Guadeloupe radar (http://www.meteo.fr/temps/domtom/antilles/pack-public/animation/animMOSAIC2.html).
 
That's it for today. Time for a spot of nosh. :-)
Ciao! (ha ha ha)
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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1 comment:

Gruntled Guy said...

It's great to see that you are still keeping up with your blog. Those of us who potentially are in harm's way appreciate hearing about the threats to us described in such a charming way.
Best.
Jan