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New disturbance in the Gulf of Mexico

By: Dr. Jeff Masters, 9:43 PM GMT on August 15, 2006

The old frontal boundary that spawned the distubance off the East Coast we're watching has spawned a new disturbance over the Gulf of Mexico this afternoon. A large blow-up of intense thunderstorms south of New Orleans marks the center of this disturbance. With wind shear only 5-10 knots, this region is probably the bigger threat to develop than its sister east of Florida, which is under higher wind shear. Developments from old fronts are usually slow, and I expect Thursday is the earliest we would have to worry about a tropical depression forming. Steering currents are weak, but a slow motion to the south or southwest away from Louisiana should begin tonight. The NHC has not run their package of preliminary model runs on this system yet, but I will post them as soon as they do.

East coast of Florida disturbance
Heavy thunderstorms continue over the waters east of Florida this evening along a broad area of low pressure that has developed from the remains of an old cold front. Wind shear is 10-15 knots in a narrow band along this old front, which is low enough to allow some development to occur. This disturbance remains poorly organized, with only a moderate amount of heavy thunderstorm activity. The Hurricane Hunter mission scheduled for today was canceled and rescheduled for Wednesday.

The computer models are forecasting that any system that forms in this area will begin moving northwestwards towards the Carolinas over the next two days, in response to a trough of low pressure swinging across the eastern U.S. When the trough moves out to sea on Thursday, high pressure is forecast to build back in, forcing the system back towards the west, or leaving it nearly stationary off the East Coast. None of the computer models forecast that the storm will grow to anything stronger than a 40-mph tropical storm.

Figure 1. Current satellite of the Gulf of Mexico.

Figure 2. Preliminary models tracks for the East Coast disturbance.

I'll be back Wednesday with my Atlantic tropical outlook for the rest of August.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

lol thel

See ya'll later
Atlantic is blowing up. Debby will be here soon and hit Florida. I am going to say 4 Atlanitc storms at once in next two weeks.
1003. guygee
Posted By: Skyepony at 1:55 PM GMT on August 16, 2006.
Guygee amazing how much the QuikScat changed as the area off SC has deepened this morning.

Skye - Kinda shakes my faith. The pass from around 10:00 UTC for Storm 93 was showing no circulation to the north, just a trough extending from the Bahamas, now that page is blank attm and the 12.5 km hi-res view shows a strong circulation.
1004. nash28
I think it will take the SW track as the BAM models have indicated.
wow weather456, you've been keeping track of how many cyclones formed so far this year..
the weak front moving through NC will likely limit the westward track of 93L. I don't know if the front is strong enough to pick it up and wisk it NE as some of the models show. I would be happy if it sat right where it is a developed further, stayed there for about a month, and then dissipated. But, that is just wishful thinking.
1007. IKE
The unreliable NAM jumped on board with a SW movement too on the earlier run.
" I would think that the front would pick it up and push it out to sea?"

well, guess that depends on how much "pull" that trough has, and "how fast" the high pressure builds in when the trough passes....... and how strong the high pressure will be.....

sounds like lots of room for error in all that! LOL
well, i need some water for my grass..... so a nice dpression with about 2-3 inches of rain will do just fine! :)
Right now I am told there is a "cold front" hovering over south-middle-south Alabama and across GA, MS, etc. That is pretty much pushing anything south of us short of the storms that develop from the daytime heating and evening cooling, etc. I would not expect it to give 93L any chance of heading across North GA, unless 93 L pushes it out of the way or it decides to recede back to the north.

The model runs that come out at 2pm should give us a better idea. It will also be very interesting to see if 93 can hold the convection through the late afternoon early evening hours.

That being said, the GFDL seems to have had a pretty good handle on the system thus far. Intensity and track IMHO.

thel-got your mail...Get with you this weekend.

and the GOM blob seems to have vanished...typical pattern. first i'm very skeptical, then the blob looks good and i think "hmm maybe i was wrong, maybe it will do something", then it falls apart.
well, the comment about 93L you get from me..... it has an extremely small ciculation..... so it could weaken petty rapidly.... or intensify....

flip a coin......
guess i should qualify my statement to the "northern" low associated with 93L..... I guess thats what you would call it!

i am still looking at the possibility that one of these lows could absorb the other....

but since you have two lows so close, it also throws extra error in the models imho.......
always a 50/50 chance
looking at the local bouy observations,
Frying Pan shaols bouy, located approximately on the western edge of 93L has a 15.5mph sustained wind from due North. The bouy 250 miles east of Charleston, SC, approximately on 93L's western edge has a 12 mph sustained wind out due south. That shows a 180 degree variation in wind direction from east to west. Is the circulation center becoming better organized, I think yes. Convection continues just south of west on 93L not directly over the center though.
1017. IKE
Looks like the main low is off of the SC coast and most models have it diving SW toward NE or east-central Florida.
1018. guygee
Posted By: thelmores at 2:23 PM GMT on August 16, 2006.
well, the comment about 93L you get from me..... it has an extremely small ciculation..... so it could weaken petty rapidly.... or intensify....

Good point thel. At least we know which surface low is 93L now! Just a surge of moderate shear could blow the top off of 93L. It looks to me that the trough axis is passing to the east of the longitude of 93L, so I think that will tend to push it south and west, and the ULL will also pull it in that direction. If the surface low moves against this steering, then I think it will get sheared.
Hello all..........It's seems to me (amateur observation)that any lack of development on the part of 93L may indeed be related to the ultimate level of wind shear since the water vapor loops seem to indicate that there is enough moisture, as opposed to dry air, in the present vicinity and it remains close to the Gulf Stream............If wind shear does not blow it apart, then it may have a good chance at development