Three Atlantic disturbances to watch
A low pressure system over the southern Gulf of Mexico (90L) has developed a large surface circulation covering most of the Gulf of Mexico, but is not a threat to develop rapidly. This morning's QuikSCAT pass shows this circulation nicely, with top winds of 35 mph to the southeast of the center. Satellite loops show that 90L's heavy thunderstorm activity has decreased since yesterday. Water vapor satellite loops show a large upper-level low pressure system also covers the entire Gulf of Mexico, with two embedded swirls. This upper level low has a cold core and is wrapping plenty of dry air into 90L. These factors, plus the very large size of the surface circulation of 90L, will keep any development of the storm slow. A Hurricane Hunter aircraft is scheduled to investigate the system Thursday afternoon, if necessary. Today's flight was canceled.
The latest computer model runs continue to point to a landfall Thursday night or Friday morning near the Louisiana/Texas border. I don't see 90L becoming a hurricane, and I give equal chances of 90L arriving at the coast as a tropical disturbance, tropical depression, or tropical storm.
Figure 1. Today's line up of tropical disturbances to watch.
Disturbance 92L east of the Bahamas
Of greater concern to me is an area of heavy thunderstorm activity associated with a surface trough of low pressure (92L) that has developed just east of the Bahama Islands. This morning's QuikSCAT pass showed an east-west oriented zone of converging winds at 27N between 69W and 72W, but no surface circulation. Satellite loops show a large area of disorganized thunderstorm activity that is not getting better organized. This disturbance is under about 10-15 knots of wind shear. Wind shear is expected to remain ten knots or less over 92L for the next five days. The computer models expect 92L will move slowly west-southwest over the Bahamas, then the Florida Straits or Cuba during the next three days. By Saturday, the GFS and ECMWF models predict a tropical depression could form in the Western Caribbean or southern Gulf of Mexico. The NOGAPS and UKMET model forecast that development Monday is more likely. These are the highest heat content waters in the Atlantic, and with a upper-level anticyclone with light wind shear expected to set up over the disturbance, the potential exists for a hurricane to form from 92L next week. The Hurricane Hunters are scheduled to investigate 92L Thursday afternoon.
Disturbance 91L between Africa and the Lesser Antilles
A tropical wave (91L) near 9N, 41W, midway between Africa and the Lesser Antilles Islands, has gotten better organized this morning. This morning's QuikSCAT pass showed a wind shift associated with the wave, but no closed circulation. Satellite loops show a modest area of heavy thunderstorm activity that is not well-organized. The disturbance is headed west at 10-15 mph, and is expected to take a more west-northwesterly track Thursday.
Wind shear is about 10 knots over the wave, and is forecast to remain below 15 knots until Thursday night. This may allow for some slow development. However, beginning Thursday night, wind shear is expect to increase and remain 20-30 knots through Sunday. This should prevent further development.
I'll have an update Thursday morning at the latest.
Jeff Masters
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Yes, Cuba will be a big player with 92L. Hopefully it holds off and tries to develop as it reaches Cuba. This would reduce the potential development at least in the short term, and hopefully disrupt any developing system enough that it can't get itself back together. The sooner it develops, the better chance it has of becoming something considerable. I think it still has another 1-2 days, at least, before it really gets a spin going. However, I dont think that is enough time to get to Cuba.
After that, looking at the position of the High, I think the models that bring the system into the Bay of Campeche are a bit too far south. I think it will stay further north riding the southern edge of the high. Now, this theory could be thrown out if the low center develops further south, as the track would then be further south. However, if it does go to the northern end of Cuba, I dont see it in the Bay. I dont doubt a stall, however.
TWC was talking about season's tendancies (sp?) seems like 92L would be headed toward MEXICO right by his/her family this year?
Turn on NCEP Fronts on IR CH2 loop. May actully have a sharper bend in it then depicted right now.
84 hrs ~3 1/2 days from now forecast
I'm from about an hour north of the Coast in Hattiesburg.
I always wondered what that was all about. Feels like we are on Apollo 13, or going to the dark side of the moon. What causes that? anyone?
So was that ensemble run if there was no shear?! Crazy how different it is.
and topography......
we all know little.....
like Richie D.....
He has drink.....
and some coffe...
mistakes its stain...
for Mississipi.....
The 8:05 didn't seem to mention that northern swirl.
The most northern swirl in 92L looks to be moving quickly west, like outta the area. The south one that's trying to wrap the convection, if it lasts should be the dominate one. That is also right about under the upper high.
hey sky watch that n swril after the blackout the jumps are neat and the south convection just might jump into the north convetion or visverser this will be cool to watch . in the dmax . cant tell yet which will win the
ALSO... new water vapor observation: The extrmemly dry air around 90L is begining to be moisened up... maybe somemore moisture could be getting pulled into the system..
The 8:05 didn't seem to mention that northern swirl.
SP,It aint much...(the N swirl) Where do you spot the other one?
There was an interesting area at 24N 74W earlier today.
Navy had picked it back up this morning.
NHC put it back on the intensity & position page the 2nd 1/2 of the 3rd. Too weak for a T#. 90 & 92L both hitting the board with actual #s..
03/2345 UTC 9.6N 43.4W TOO WEAK 91L
03/2345 UTC 24.8N 72.4W T1.0/1.0 92L
03/2345 UTC 26.8N 87.7W T1.5/1.5 90L
03/2345 UTC 21.5N 48.5W TOO WEAK MELISSA
03/1745 UTC 9.6N 41.0W TOO WEAK 91L
03/1745 UTC 25.8N 87.0W T1.0/1.0 90L
03/1745 UTC 21.2N 47.2W TOO WEAK MELISSA
And as for that burst of convection over 90L; lets not get too ahead of ourselves. It is a very small area of convection and it is still away from the center. We need to see some convection form over the center for this to really become a depression. Maybe after the blackout we might see something, but that little bit of convection doesn't tell me anything.
91L looks very weak and too disorganized to get its act together before the shear develops.
92L looks like it might be trying to consolidate its mass where all the convection is developing. However, this could just be a byproduct (sp?) of the convection from the north just happening to run into the new convection from the south. That main band of convection almost looks like a squall line rather than a really tropical feature.
That North one seems to be treking too fast to win. Turn on the NWS fronts ~ at the tip of the one that appears you can see it well with the last bit of sunlight on it & watch it faintly travel west after. Or we see 2 different N swirls.
Not just you, it has. Will have to watch to see if this continues, but I think it will. The models were saying this would happen, so I am not too surprised. Of course, many of the models didn't expect it to be this weak!
a Blonde Male that loves Mexican Food....
wink, wink, wink...
:0)
To funny- The photos have really made people think.
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