LRandyB's Tropical Weather Discussion

Last Updated: 2:24 PM GMT on June 06, 2013 — Last Comment: 11:10 PM GMT on June 07, 2013

	Tropical Weather Discussion for Thursday, September 1, 2011

Posted by: LRandyB, 6:24 PM GMT on September 01, 2011

Hi folks!

Well, after two weeks in the Caribbean flying Irene, I am back at Keesler AFB in Biloxi and the season is starting to roll along. We have Hurricane Katia in the Atlantic, a disturbance in the North Atlantic, and a disturbance in the Gulf. And while no one is talking about it yet, there is a fairly vigorous wave just off Africa a little south of the point where Katia got going.

In the Gulf of Mexico ......

The big news here is Invest 93L over the central Gulf of Mexico. This system is currently very disorganized but is producing a broad area of showers and thunderstorms. NWS has issued flood watches through Sunday for most of the coastal counties from LA to NW FL in anticipation of the heavy tropical rains produced by this system. Right at the moment, an upper level low over S LA is helping to drive westerly shear over the invest area. But that low is being driven westward by the broad Bermuda High over the south central US and is expected to move far enough away over the next 24 hours to allow the shear to relax over 93L. The models call for some modest development of this system but proximity to land and some dry air north and northwest of the system may keep it from becoming too serious a problem. The biggest problem, as it is with most tropical systems, will be torrential tropical rains over the northern Gulf Coast. Compounding that issue is the fact that at the moment the models reflect a lack of steering flow for the next couple of days so 93L, whether it develops or not, isn't going anywhere too fast.

I was schedule to fly 93L today buit that tasking was canceled. I'm scheduled on a crew to fly an invest in 93L tomorrow morning. Being so close, it won't take us long to get there. I'll let you know what we find when I get back on the ground tomorrow.

In the Western Atlantic and Caribbean .....

In the Caribbean, a trough of low pressure in the southern Caribbean is producing thunderstorms in Central America but otherwise, the Caribbean is enjoying mostly clear conditions.

In the western Atlantic, a disturbance in the North Atlantic near 38N 62W appears to be a low level wave interacting with an upper level col or area of divergence between an array of low pressure systems SW, SE, and NW of the wave. NHC gives this system a 50% chance of development but even if it does develop, it is forecast to move NE into the open Atlantic.

In the Atlantic ....

The big news really in the Atlantic is Hurricane Katia approaching 16N 48W as of this writing. Katia has managed to remain fairly organized although it was looking less impressive on satellite this morning. The forecast calls for Katia to continue slow strengthening as it moves WNW. The models are beginning to diverge at the end of the long range forecast and at the moment it's hard to say whether Katia will recurve into the Atlantic or continue on a WNW track toward the US. We'll have to wait a couple of days for the models to get a better handle on the trough over the eastern US.

Lastly, there is a new wave that has emerged off the African Coast. I don't pay attention to waves fresh off the coast as they always look good until they have been over water for 24 hours or so but this one has persisted for the last 24 hours over water and in fact looks much like Katia looked a few days ago when it was in the same area. None of the models develop this wave but we'll have to keep an eye on it as the models typically don't handle genisis very well.

I'll try to come back from tomorrows flight with some pictures!

For those with iPhone, iPod Touches, and iPad's, there is a new app on the App store designed to help track the Hurricane Hunter flights and all the storms in the Atlantic. It's the first app I have seen that plots the flight tracks and the data generated by the flights.

http://itunes.apple.com/us/app/hurricanehunterapp colallc/id456831217?mt=8
Give it a try. And let me know what you think (No, it's not my app but I know the creators).

Have a great day!

Randy

TS Lee