ATL: MICHAEL - Post-Tropical - Discussion

[Extratropical94]

I guess I probably know the answer since there's no thread on it yet, but has recon been scheduled yet?

OUTLOOK FOR SUCCEEDING DAY: POSSIBLE LOW-LEVEL
INVEST IN THE WESTERN CARIBBEAN NEAR
17.5N 86.5W FOR 07/1800Z

There might be a mission on Sunday.

[AutoPenalti]

Note that current shear does not equal future shear. GFS indicates quite strong shear developing across the Gulf as the disturbance moves northward on Monday/Tuesday. I think we're looking at another sheared TS, similar to Gordon. Landfall somewhere between Pascagoula, MS and the mid FL Panhandle Wed afternoon. Went with 45 kts on my forecast. Certainly could not rule out 55-60 kts, but not forecasting that. Not much weather west of the track, and squalls could extend all the way east across the FL Peninsula Tue/Wed.

http://wxman57.com/images/shear.png

That's a lot of shear for it to even survive, but considering how warm Gulf temps are, any small change in flow and we may have something.

[chaser1]

Note that current shear does not equal future shear. GFS indicates quite strong shear developing across the Gulf as the disturbance moves northward on Monday/Tuesday. I think we're looking at another sheared TS, similar to Gordon. Landfall somewhere between Pascagoula, MS and the mid FL Panhandle Wed afternoon. Went with 45 kts on my forecast. Certainly could not rule out 55-60 kts, but not forecasting that. Not much weather west of the track, and squalls could extend all the way east across the FL Peninsula Tue/Wed.

http://wxman57.com/images/shear.png

Regardless of present shear analysis, I'll bet your anticipation of the upper shear in the N. Gulf is spot on (maybe slightly negated by any NNE track motion at the time?) However, I'm just not seeing the present upper environment in the NW Caribbean improving that quickly and anticipating a slower evolution; one that might eventually track slightly more to the east (Panama City to St. Marks) with landfall not occurring until Thursday or Friday. I suppose a tight core over anomalous warm SST's could present the opportunity to spin up to a min. hurricane, but I sure wouldn't bet on any continuity of strength if increased shear were occurring near landfall.

[chaser1]

Looking at present visible satellite, I'm just not convinced that the low level swirl co-located with where 91L is presumed to be will (or is) a true dominant point where genesis will occur. The turning is very evident but without convection and this feature appearing to be moving to the west, this area of vorticity could just be one of several vorts that have been shot out of a straw like a spit-ball. "Belize-it" or not, this particular feature might just be transient as well. "Sooner" development would seem to work in tandem with a further west initialization such as what the EURO might suggest, and also imply a track somewhat more to the left (Biloxi/Mobile/Pensacola?). I still believe that a true COC will eventually evolve closer to where the MLC is (or will be). Unless the mid level low (which I believe is east of that point) begins to move westward, then eventual development might be a bit east of some of the more western biased models. It's unknown whether or not that occurs, but the implications would certainly suggest a possibility of eventual landfall a little farther to the east. It's also my thinking that if (and the longer) genesis were delayed, then the farther east the track will be as well. Looking at the present lack of a clear COC and assuming that the present tracked LLC is merely transient, I'm leary of the speed in which nearly all models suggest increased organization supposedly beginning around 12Z Sunday.

not necessarily, if you notice in the models, the system has been stalling or doing a loop, if the center forms farther east or the whole thing moves slower the next couple days it may very well go farther west as the ridging would have built back in by then. the NE turn on the models is already barely titering on the edge of being trapped.

True enough; Of course that suggests yet a third possible scenario? Begins to deepen just prior to drifting west over Yucatan where it becomes virtually trapped and essentially dissipates over land (with a remnant low perhaps eventually moving NNE ahead of the southeast sagging cold front)?

[psyclone]

The CPC 6-10 day outlook shows the max above normal precip anomalies along the northeastern gulf coast from near cedar key to near or just west of panama city..and on northeastward into central and southern GA. that would be consistent with a sheared, right loaded ts landfall near or just west of that bullseye.

[ScottNAtlanta]

Nothing is going to spin up until the feature on the other side in the Pacific dissipates. It is competing with the Atlantic side (and currently winning). Until it comes onshore, I dont see anything spinning up on the other side, and its barely moving as is.

[Cypresso]

From ABC 13 here in Houston:
"A pattern change coming to the United States this weekend will increase our rain chances again early next week. This pattern will draw in a large amount of tropical moisture while at the same time blocking fall fronts from reaching Houston. That means we'll also have to keep a watchful eye on a developing tropical disturbance lifting out of the Caribbean and into the Gulf."

I took note of the "blocking fall fronts from reaching Houston." That makes me think that Texas does need to be alert for this one at this time. Smaller chance, but one needs to be prepared. Opal looks like it had a Fall front push her eastward in '95.

[cycloneye]

Surface observations and satellite data indicate that a broad area
of low pressure is centered near the coast of Honduras. This system
is producing a large area of disturbed weather extending from
Central America east-northeastward across the Western Caribbean to
Hispaniola. Environmental conditions are expected to become more
favorable for development, and a tropical depression will likely
form over the northwestern Caribbean Sea or the southern Gulf of
Mexico by late this weekend or early next week while the system
moves slowly toward the northwest and north. Regardless of tropical
cyclone formation, this disturbance will continue to bring
torrential rains primarily to portions of Central America, and these
rains should then spread over western Cuba and the Yucatan peninsula
during the next few days.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...80 percent.

[Aric Dunn]

some convection beginning to build near that vort along the coast with a large surge of building convection coming in from the east.

[ozonepete]

Note that current shear does not equal future shear. GFS indicates quite strong shear developing across the Gulf as the disturbance moves northward on Monday/Tuesday. I think we're looking at another sheared TS, similar to Gordon. Landfall somewhere between Pascagoula, MS and the mid FL Panhandle Wed afternoon. Went with 45 kts on my forecast. Certainly could not rule out 55-60 kts, but not forecasting that. Not much weather west of the track, and squalls could extend all the way east across the FL Peninsula Tue/Wed.

http://wxman57.com/images/shear.png

Bold prediction for so far out. Let's see how you do.

[N2FSU]

I respectfully disagree with the Houston Met. This doesn’t look to be anywhere near a Texas threat.

[Emmett_Brown]

I find it interesting that models are suddenly bullish on development in the very short term of a just a couple of days, when 91L is still so ill defined. If I had not seen the model runs, and just looked at satellite end surface obs, I would guess that this is at least 4 days away from forming... the eternal watched pot that never seems to boil. Sure, conditions will be improving, but this "gyre" has much more impressive vortices (like 97E specifically). And yet, almost all models now show a TD forming in about 48 hours in the NW Caribbean out of this broadly turning defuse blob that is part of another broadly turning even more diffuse blob. Is it possible that all the models are being fooled at once? The GFS didn't want to develop this at all as recently as 6Z today (although ensembles did).

[Aric Dunn]

I respectfully disagree with the Houston Met. This doesn’t look to be anywhere near a Texas threat.

Then take a closer look at the factors in play and timing ( as of right now)

[robbielyn]

I find it interesting that models are suddenly bullish on development in the very short term of a just a couple of days, when 91L is still so ill defined. If I had not seen the model runs, and just looked at satellite end surface obs, I would guess that this is at least 4 days away from forming... the eternal watched pot that never seems to boil. Sure, conditions will be improving, but this "gyre" has much more impressive vortices (like 97E specifically). And yet, almost all models now show a TD forming in about 48 hours in the NW Caribbean out of this broadly turning defuse blob that is part of another broadly turning even more diffuse blob. Is it possible that all the models are being fooled at once? The GFS didn't want to develop this at all as recently as 6Z today (although ensembles did).

As Doc would say:” Are you sure about this storm?”

[N2FSU]

I respectfully disagree with the Houston Met. This doesn’t look to be anywhere near a Texas threat.

Then take a closer look at the factors in play and timing ( as of right now)

Oh I have, and I respect and look for your analysis as much as anyone on here Aric. Maybe I should have worded that differently. If I had to put money down on a forecast right now, I would say Texas is a long shot. I know we are looking at conditions that are more like August than October, but I’m still giving climo quite a bit of weight. I may be totally wrong, but that’s the beauty of a weather message board, I’m not a professional and I can make my prediction this far out.

Interesting days ahead.

[Aric Dunn]

I respectfully disagree with the Houston Met. This doesn’t look to be anywhere near a Texas threat.

Then take a closer look at the factors in play and timing ( as of right now)

Oh I have, and I respect and look for your analysis as much as anyone on here Aric. Maybe I should have worded that differently. If I had to put money down on a forecast right now, I would say Texas is a long shot. I know we are looking at conditions that are more like August than October, but I’m still giving climo quite a bit of weight. I may be totally wrong, but that’s the beauty of a weather message board, I’m not a professional and I can make my prediction this far out.

Interesting days ahead.

yes very interesting days ahead

and it really comes down to timing in this case. there is a very fine line right now with the models. can go either way at the moment.

[cycloneye]

00z Best Track:

AL, 91, 2018100600, , BEST, 0, 165N, 847W, 25, 1007, DB

[gatorcane]

Hard to believe the GFS which makes this a hurricane in 3 days. Sat imagery looks like a mess with tons of shear:

http://rammb.cira.colostate.edu/ramsdis ... display=12

[Aric Dunn]

Hard to believe the GFS which makes this a hurricane in 3 days. Sat imagery looks like a mess with tons of shear:

http://rammb.cira.colostate.edu/ramsdis ... display=12

we know all to well how fast TC"s can change. only takes 12 hours ..

[NDG]

Hard to believe the GFS which makes this a hurricane in 3 days. Sat imagery looks like a mess with tons of shear:

http://rammb.cira.colostate.edu/ramsdis ... display=12

Which makes sense that the GFS doesn't do much with it over the next 48 hrs until the UL environment starts changing over the eastern GOM.