Thursday, August 09, 2012

Tropical Storm Ernesto, the remains of Florence, Tropical Depression 7 and the Atlantic blobette: August 9, Update A

Today was another exciting day of record breaking news! In the Olympics earlier I watched David Rudisha from Kenya break the world record for 800m, and now I just watched Usain Bolt from Jamaica win the gold for the 200m, after having won the 100m – the first time anyone has done this in consecutive Olympics. Well done Kenya and Jamaica! Over here, across the Atlantic, records are also being broken… my website clocked over 30,000 hits today! J (I’d like to take a moment to thank whoever the other person is that’s been clicking on it all these years … ;-)) I am celebrating in style with wine AND super yummy raspberry-chocolate cake. It’s the thing to do.

Before we get on with the show, I’d like to show you the er show (hmm… that sentence didn’t quite work out how I thought it would). Here is the NHC graphical depiction of interesting tidbits in the Atlantic:

Someone was having fun with the crayons today, weren’t they? We have Tropical Storm Ernesto over Mexico on the left. There are the remains of Tropical Storm Florence just north of the Caribbean (10% chance of reforming). Our newly formed Tropical Depression 7 (pre-Gordon). And the latest beauty that just came out of Africa on the right (currently 30% chance of forming and maybe the future Tropical Storm Helene).

Tropical Storm Ernesto
Ernesto is hanging onto his circulation with both paws as he crosses Mexico. His winds are officially at 40mph, which makes him a weak Tropical Storm (range: 39-73mph), but the central pressure, at 999mb, is low for this wind speed. This is partly because his circulation in the entire troposphere has remained quite strong as he moved over land, but also because he is in a narrow section between the Gulf and the Pacific and is drawing moisture from both sides (sea surface temperatures are 30 deg C or higher in both ocean basins). Although the official forecast downgrades him to a Tropical Depression by the morning, he still looks stronger than that to me – both in terms of circulation and convection. You can see this for yourself in the satellite images of Ernesto.

The visible one, in shades of grey (not Shades of Gray!), shows the center of circulation at about 18.1N, 96.7W. The infrared image, in shades of colour (not shades of color!) shows the huge amount of convection in Ernesto. It’s been pouring rivers (the orange, red and gray parts), probably accompanied by lightning (red and gray parts) and stuff (er, a technical term ;-)).

He is moving westward at 14mph, which means he has some more land to cross before getting over water, but I think given his integrity there is a chance that he might be a storm all the way into the Pacific. Once upon a time when a storm crossed from one basin to another it would change names and take on the next name in the alphabet in the new basin. In these modern days and fast times if the storm maintains Tropical Storm status as it crosses Mexico (and doesn’t get downgraded to a tropical disturbance), then it will keep its name in the new basin as well. The NE Pacific is already at G in the alphabet with Tropical Storm Gilma (which was a hurricane earlier today), so unless Ernesto has a Strength of +2 he may transmute into Tropical Storm Hector! (gaming parlance ;-))

Remains of Tropical Storm Florence
The storm-formerly-known-as-Florence still has a bit of circulation and earlier today gained some nice shapely rain clouds as she went over a patch of ocean where the water was over 26 deg C in the upper ~100m. But wind shear is a bit too strong for her and she’s still got that dry and dusty Saharan Air (from yesterday) on her east side, so she is looking rather pathetic again. I won’t mention her again unless she has another resurgence.

Tropical Depression 7
This is our Atlantic Blob from yesterday and the one I thought would evolve into Gordon a couple of days ago, when he was just a blip on the radar (quite literally J). He is officially at 13.7N, 45.5W, moving W at 20mph. Winds are 35mph, central pressure 1009mb. He is not very organized at the moment, so it is a bit tricky for me to see his center. He could be moving west, or it could be somewhere else in the system, in which case he is moving SW. I’ll stick to the official center and direction for now.  The forecast track makes him a weak Tropical Storm tomorrow and takes him through the middle of the Lesser Antilles island chain in the middle of the weekend, and then up to Jamaica for Tuesday. At the moment I agree with the NHC and their intensity assessment – there is little wind shear, circulation is improving in the lower half of the troposphere, sea surface temperatures are warm which allows for some improvement. But he will still be impacted by dry air from the edge of the SAL (see figure yesterday) and there’s a chance that wind shear will increase a little tomorrow, which will keep his intensification slow. I think his track may be south of the official one (at least over the next day or two), but my data is not very good at the moment and I hope I’ll have more on this tomorrow.

Atlantic Blobette
This is the new blobette I was referring to yesterday. It emerged off Africa today and has good circulation in the very lowest region of the troposphere (I do not have any data for the rest of the troposphere this far east) as well as good convection. It has to cross the Atlantic and the SAL, but she may be the future Tropical Storm Helene. I’ll be keeping an eye on this one, rest assured!   

Thus ends today’s epic entry. One more important news item before I go back to watching the Olympics: BBC is making a TV movie of the origins of Dr. Who! About time. (puns always intended J).

(Goodness me… some of these long-jumpers can jump over 3.5 times my height!! And that’s when I’m wearing heels. Hmm… I suppose I can jump over 3.5 times my cat’s height. And that’s when I’m wearing heels… ;-))

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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 "run away, run away" (Monty Python), I'll let you know.

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