ATL: INVEST 92L - Discussion

[Cainer]

I think it will. But it appears that LLC is dissipating. Definitely moving SW now, something we've seen many times. Look for a new center to form farther north closer to the convection.

Could this turn out to be a situation similar to Debby, where continual NE center relocations lead to the disturbance moving in a more northerly direction?

[USTropics]

sorry about that Portastorm. I forget to include those when using the quick reply.

[GCANE]

Air is destabilizing. Good flare up of afternoon thunderstorms over Yucatan.

[Portastorm]

sorry about that Portastorm. I forget to include those when using the quick reply.

Muchas gracias ... now let's get back to 92L. Looks like we might have something to actually talk about soon enough.

[Rgv20]

Afternoon discussion out of the NWS in Brownsville..

LONG TERM /SUNDAY THROUGH FRIDAY/...UNCERTAINTY WITH A WEAK LOW OFF
THE NORTHWEST TIP OF THE YUCATAN PENINSULA DOES CAST A BIT MORE OF A
CHALLENGE INTO THE LONG TERM. THE LOCATION OF FINAL DEMISE OF THE
LOW...AND ITS INTENSITY...COULD CHANGE THINGS A LOT. HOWEVER...FOR
NOW FOLLOWED PERSISTENCE WITH AN EYE TOWARD AN AREA OF SURFACE LOW
PRESSURE CONTINUING TO MOVE EAST OVER THE WEEKEND...WITH ABOUT AN
EVEN CHANCE OF DEVELOPMENT INTO A TROPICAL CYCLONE. MOVEMENT WEST
WOULD BE MORE FAVORABLE THAN MOVEMENT NORTH...WHERE A MID LEVEL
TROUGH WOULD LIE ROUGHLY OVER THE SOUTHEAST UNITED STATES. THE
EUROPEAN MODEL SEEMS TO TAKE A QUICKER ROUTE TO THE WEST...WHICH
COULD ULTIMATELY BRING SLIGHTLY HIGHER RAIN CHANCES TO THE RIO
GRANDE VALLEY...BUT THE AMOUNTS ARE NOT YET MAKING A BIG DENT IN THE
ONGOING FORECAST. EVEN A BLEND OF SOME OF THE OTHER MODELS...WHICH
TRACK MORE NORTHWEST OR SO...COULD END UP ON A TRACK CLOSER TO THE
LOWER TEXAS COAST THAN NOW. I BLENDED SLIGHTLY HIGHER POPS FROM THE
EUROPEAN IN FOR NEXT WEEK...BUT THIS AFFECTED THE MARINE AREAS MORE
THAN OVER LAND. FOR NOW...

[tailgater]

I don't see a second llc. trying to form the first one still looks tight to me still stationery its not going to develop with that upper level low right on top of it though.

[Stormcenter]

Not as pronounced as it was this morning. IMO

I don't see a second llc. trying to form the first one still looks tight to me still stationery its not going to develop with that upper level low right on top of it though.

[tailgater]

I don't see a second llc. trying to form the first one still looks tight to me still stationery its not going to develop with that upper level low. right on top of it though.

Probably not but the 850 vorticity has increased

[BigA]

Not as pronounced as it was this morning. IMO

I don't see a second llc. trying to form the first one still looks tight to me still stationery its not going to develop with that upper level low right on top of it though.

Running through the 8-hour loop, the circulation looks about the same as it was this morning. But yes, there is little chance that this can get convection over the center with an ULL directly to its northeast. The models (CMC, GFS, NAVGEM; haven't seen the ECMWF vorticity) have been consistent with weakening the ULL, but it doesn't appear to by dying off yet.

[HurriGuy]

But regardless, the convection is building to the north instead of being sheered apart. I would think the ULL must be dying off. Still a newbie, and love feedback!

[ozonepete]

wxman57 forget models member opinions and all that....just your professional take....does this mess even make td?

I think it will. But it appears that LLC is dissipating. Definitely moving SW now, something we've seen many times. Look for a new center to form farther north closer to the convection.

Hi wxman. I agree with you here, which is almost always the best thing to do, lol. That LLC west of the Yuatan is dissolving rapidly and a new center is forming well N or NNE of it very close to the convection. One would think this really has a good chance to develop now, especially if the forward speed stays down. Would you say the upper Texas coast is in play now?

[HouTXmetro]

Looks like the last few frames show the LLC from earlier slowly consolidating northward toward the ULL. But that ULL is still very present and i think some of us (including myself) are getting confused as to if a new LLC is forming due to the increased convection around the ULL.

http://www.ssd.noaa.gov/goes/east/gmex/flash-wv.html

[HurriGuy]

I agree with both of you guys. It looks really clear on infared that the two are merging.

[ozonepete]

Not as pronounced as it was this morning. IMO

I don't see a second llc. trying to form the first one still looks tight to me still stationery its not going to develop with that upper level low right on top of it though.

Running through the 8-hour loop, the circulation looks about the same as it was this morning. But yes, there is little chance that this can get convection over the center with an ULL directly to its northeast. The models (CMC, GFS, NAVGEM; haven't seen the ECMWF vorticity) have been consistent with weakening the ULL, but it doesn't appear to by dying off yet.

The first LLC we were watching all day is already stretched out from east to west and just about gone. This is back to being a tropical disturbance with multiple candidate LLCs rotating around near or under the best convection and MLC. We should see a final LLC win out much more to the NNE under the southern end of the blossoming convection. That first one is not going to be involved anymore.

[Sanibel]

Air is destabilizing. Good flare up of afternoon thunderstorms over Yucatan.

The displaced convection is filling-in in a curved band. The convection over Yucatan is bursting. This looks like a cyclonic loop and possible direction change. Could be about to take-off.

[Stormlover2012]

Direction change to florida?

[Alyono]

watch the broad low, not any eddy. I'd expect the broad low to move generally to the WNW. May be more of threat to Texas now than NE Mexico, especially since most of the storms should be north of the center.

[Dean4Storms]

Evidently the Mobile NWS office see's what I was talking about earlier about a circulation moving northward toward the upper Gulf Coast.

From this afternoons AFD....

.MARINE...A WEAK SURFACE CIRCULATION OVER THE NORTH-CENTRAL GULF
COAST WILL ERODE TONIGHT AS A SURFACE CIRCULATION FORMS OVER THE
SOUTHERN GULF OF MEX AND MOVES NORTH. THIS CIRCULATION WILL MOVE
ONSHORE ON THE LOUISIANA COAST SATURDAY NIGHT INTO SUNDAY. MODERATE
TO AT TIMES STRONG ONSHORE FLOW IS EXPECTED TO MOVE OVER AREA
COASTAL WATERS SATURDAY INTO SATURDAY NIGHT. AM NOT EXPECTING MORE
THAN EX CAUTION LEVEL WINDS/SEAS ATTM...THOUGH DEPENDING UPON HOW
THE SYSTEM DEVELOPS AND MOVES NORTH IS STILL IN FLUX.

[BigA]

Taking a closer look, it makes sense that the LLC is dissipating, while the overall large-scale circulation remains. Looking at the 850 vorticity map, the vorticity over the circulation hasn't weakened. However, that is satellite-derived and likely unable to pick out small-scale changes such as the weakening of the small LLC. Once (if?) the upper-level low weakens, I like 92's chances as long as it moves more west than north in the short run.

[nautical wheeler]

Do we have multiple LLC's or just a naked LLC and a convective MLC? Is that MLC with the convective activity that same ULL we were looking at this morning? Did it spin itself down?

I figured I would come back from work and see the ULL having dissipated completely and convection starting to wrap itself around the LLC.