Thursday, August 25, 2016

Hurricane Gaston and the Atlantic Blobette: August 24, Update A

So much to talk about that I'll just go and get another bottle er... I mean glass... of wine! ;-) 

Hurricane Gaston
Gaston is now the Hurricane that I knew he would grow to be, because, after all... 

No one's slick as Gaston
No one's quick as Gaston
No one's neck's as incredibly thick as Gaston
For there's no man in town half as manly
Perfect, a pure paragon
You can ask any Tom, Dick or Stanley


(Name that song/movie! :-))

Gaston is currently at 18.7N, 42.2W heading NW at 17mph. His winds are officially 75mph, central pressure is 988mb, which makes him a very weak cat 1 (cat 1 range: 74-95mph). 

As the song says, his neck is pretty thick - the main region of convection spans almost 3 degrees of latitude, which is around 200 miles! I agree that he is a cat 1 storm because he doesn't have an eye, but his circulation and convection is pretty good: 

He may be a little stronger than the official forecast, but I'd say no more than 85 mph at the moment which makes him a mid-sized cat 1 storm. 

There are three major factors influencing his intensity. 

First, the sea surface temperatures are around 27 deg C, which is warm enough to sustain him (temps over 26.5 deg C are warm enough) and the upper 75-100 m of the water column is warmer than 26.5 deg C. This means that even if he churns up the surface, he has another 75-100m of warm water to keep him going. Lucky Gaston! This will help to increase his intensity.

Second, the wind shear. He is heading into an area of stronger wind shear. You can see this in this University of Wisconsin wind shear tendency map:

Gaston is marked by the hurricane symbol. He is moving NW, into that area of yellows/oranges/reds. That is an area of higher wind shear. From another map, I see that the wind shear is going to be around 35-45 mph. This is almost half of his actual wind speed, so this will definitely inhibit his development and may make him quite a bit weaker. 

Third, the Saharan Air Layer (SAL). He is pretty much at the edge of the SAL so this will no longer be an inhibiting factor:

Overall, I think the wind shear is going to be the dominant factor at the moment so I don't think Gaston will get much stronger until he gets past that. This is in agreement with the NHC. 

NOAA kindly redirected me to another site (from the discontinued site where I used to get my pressure maps from), which supposedly had the data I need to figure out his track, but alas, it doesn't seem to be working. At all. Grr. Double grr in fact. So, looking at the meager information I can find, it looks like his track is going to take him towards Bermuda (you guys - haven't we already spoken about turning off the hurricane magnet during hurricane season?), but I don't have enough info to be able to say for sure what is going on! I'll keep pressing the buttons until something works. Grrr. 

Atlantic Blobette
I saw a flurry of media about a storm hitting Florida. Looking at this baby objectively, I'd first like to say 'Don't Panic' (HHGTTG). :-) (at least not until you really need to!!)

Officially, this blobette has a 50-50 chance of becoming a Tropical Storm in the next 2 days and I wouldn't be too surprised if she became Tropical Storm Hermine tomorrow - or as soon as she leaves an area of high wind shear (which may possibly coincide with when the Hurricane Hunter plane returns the latest data). 

Currently it looks like she is centered somewhere around 19.5N, 66.5W although it is quite difficult to see this because she is very disorganized:
She has definitely not had her morning coffee or done her hair or make-up yet! However, she is making a lot of noise as she wakes up. There is a lot of very strong convective activity, with thunderstorms and possible tornadoes in that red/grey area in the infrared satellite image above. Looks like mostly cloudy weather over the VIs, but Puerto Rico is getting bunches of rain. 

She is experiencing considerable wind shear - around 35 mph - which has kept her in check. Her vorticity is good in the very lower troposphere, and although there is some in the middle troposphere, the wind shear has pushed that to the east of the lower level circulation (which is how the wind shear is keeping her in check). 

The not-so-groovy news is that she is going to move into an area of lower wind shear in the next day or so... and this is why I expect her to be a Tropical Storm in the next 24 hours. 

The current tracks (from the models) do show a track towards Florida. As before, if NOAA hadn't discontinued their service (see above 'grr' comments or yesterday's comments!), I would be able to access the data I need to try and confirm or deny this. I will keep on looking and searching for the data of course. As I said yesterday, the only consolation is that the NHC track has improved and is really good at 1 day out, and not too bad at 2 days out. If you want a longer lead time, then that is not yet going to happen. 

The Turks and Caicos/Hispaniola/Cuba had better be ready for some rainy thundery sort of weather! 

That's it for today!
Toodles,
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.

1 comment:

Bob helber said...

Beauty and the Beast.