Hurricane Gert, the Atlantic Blob, the Atlantic Blobette, and the Stormling: August 16, Update A

I’ve had a glass of wine, a cup of tea, a slice of cake…hmm... is it time for a spot of ice cream to round off the evening? ;-) Speaking of cups of tea, we have a lot brewing out there today. It’s a veritable smorgasbord of stormy delights: a Hurricane, a Blob, a Blobette^TM, and a Stormling^TM!! Mother Nature is having a jolly good time! 

Hurricane Gert

She is currently at 40.1N, 58.4W heading ENE at a whopping 37mph. She is officially a cat 2 storm with winds of 105mph (cat 2 range: 96-110mph), minimum pressure of 967mb.

I would say she was definitely a hurricane of around 90-100mph earlier today because she had a well-formed eye, as we can see in this Infra-red satellite image:

But it looks like it dissipated about 2 hours ago (at least), so I would actually classify her as a cat 1 storm with winds of around 85-90mph now.

She has been moving over an area of relatively warm water, even though she is out of the tropics. This is because she is over the Gulf Stream, which is a very strong warm ocean current that moves along the eastern seaboard to Cape Hatteras before it leaves the US coastline and heads across the Atlantic, carrying warm water from the tropics to the northern latitudes (and the UK – land of cups of tea and jaffa cakes). The upper ~70m of the Gulf Stream in this area is warmer than 26 deg C, so she has definitely had something to eat along the way!

The physical structure of Gert has remained robust, as we can see from the vorticity (circulation) maps. Here are the maps at 850mb (lowest level of the troposphere):

500mb (middle troposphere):

And 200mb (upper troposphere):

Again, this indicates that she is a hurricane. But I think she is on a downward spiral (pun proudly intended as every pun is its own reword ;-)) now as she is going to move away from that warm water and is moving into an area of stronger wind shear (which we can see from her satellite image, which shows some of her clouds being whisked away to the northeast).

Atlantic Blob and Blobette

These two are so close to each other that I might as well group them together! One (91L, if you follow those numbers and things) is at around 13.5N, 53W, heading westward at around 15-20 mph, and the other (92L) is at around 14.5N, 40.5W, moving WNW at 15-20mph.

From the vorticity (circulation) maps, we see that although there are two very nice red splodges (highly technical term for ‘red splodge’) in the lowest level of the troposphere in those regions, a little higher up, in the mid-troposphere, the one at around 53W (to the left) isn’t looking as good at the moment as the one around 40W (to the right), which suggests the storm structure is better for the second Blob.

From the satellite images, we see that there really isn’t much convection associated with either of them at the moment:

Although the left one (weaker structure) has more convection than the right one. But there are good reasons for the convection looking like this.

First, this Blob and Blobette are skirting the edge of the Saharan Air Layer (remember that from earlier this season?) which means there is not much room for the atmosphere to be moist enough to help a storm:

Second, the reason why the one on the left, although with a weaker structure, has more convection is because it is approaching an area of warmer water. As it moves further west, two things will happen: it will move away from the SAL and it will continue to move over warmer water. Also, there isn’t much wind shear around here, so I anticipate this storm to develop, although slowly.

The NHC track looks like this Blob will cross the Lesser Antilles and head into the Caribbean on Friday.

Meanwhile, the Blobette is a little more to the north and is heading WNW. That means she will remain closer to the SAL, so even though she has a better structure and the water is around 27 deg C (warm enough for it to be fed), it will be inhibited from developing too quickly – if at all really, because it looks like the wind shear will increase if she carries on in that direction.

The NHC thinks this Blobette will head north of the Leeward Islands – I think it’s a little too soon to say for sure on this one though.

Stormling

This little Stormling currently has a 0% chance of becoming a storm (in the next 2 days anyway) according to the NHC. I think they just threw it on there because they were bored. ;-)

This one just came off Africa and is somewhere in the vicinity of 12N, 25W, heading generally westward at around 15mph. From the vorticity maps you can see some activity in that area in the lower and middle troposphere, but it is definitely not well developed yet. There isn’t much convection with it yet either, but because of the vorticity, it is definitely one to keep an eye on.

That’s it for now! Gosh… so much for short posts for the rest of this year! Why do I even say these things? J

Ciao for now!

J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm
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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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