ATL: ALBERTO - Post-Tropical

[Dean4Storms]

18Z GFS a bit stronger with the cyclone this run, 998 mb just north of Tampa Bay by 0Z Saturday evening, then inland North Florida by 6Z Sunday morning.

Yea, left hook to Tallahassee Sunday afternoon then a creep up into SW GA by early Monday.

[Nimbus]

Low pressure systems can form new "centers", that's established and important to this forecast as mentioned. Are any of those reasons present in this setup? Why would they (or wouldn't they) manifest.

A poorly organized low level system that is under even light shear from the west has the potential to form a new surface low under the dislocated convection.

This was mentioned several ago on this thread.

Potentially the shear might ease up later in the forecast according to some models, so if the storm hasn't been sheared inland over the peninsula in 4 days there is the possibility of a longer term event up near the central gulf coast.

[drewschmaltz]

Low pressure systems can form new "centers", that's established and important to this forecast as mentioned. Are any of those reasons present in this setup? Why would they (or wouldn't they) manifest.

A poorly organized low level system that is under even light shear from the west has the potential to form a new surface low under the dislocated convection.

This was mentioned several ago on this thread.

Potentially the shear might ease up later in the forecast according to some models, so if the storm hasn't been sheared inland over the peninsula in 4 days there is the possibility of a longer term event up near the central gulf coast.

Yes, it was, several times. Buy why does it form under the dislocated convection?

[northjaxpro]

Also Dean, apparently this is like the second straight GFS run which shows apparent stalling or gradual turn westward as the cyclone reaches up near the Big Bend region of Florida. It looks like ridging is trying to establish itself from early Sunday morning through early Monday morning. It will be interesting to see if this happens.

[Sciencerocks]

[AJC3]

Going to all depend when the center forms

It's not really a question of where the center initially forms now. It's a matter of *if* there will be any downshear (NE/ENE) reformation(s) of the center toward where you might expect to get jet forced pressure falls in a high shear environment. If there aren't any, then the center will track north more toward the central Gulf Coast, closer to the non-GFS solutions. If it does take place, then you'll see a track which will wind up being a combination of a northward motion coupled with NE propagation of the center, which would take the center on an apparent NNE track over the eastern GOMEX or near/over Florida, which is closer to the OP-GFS.

Not if you look at the 18z GFS..... it has the surface Low developing early Saturday maybe 50 miles west of Key West whereas just about all the other guidance is north of the Yucatan peninsula.

That's essentially the "jump" I spoke of. All of the guidance, GFS included, shows the initial spot low near, or a little west of the NE tip of the Yucatan.

[Nimbus]

Low pressure systems can form new "centers", that's established and important to this forecast as mentioned. Are any of those reasons present in this setup? Why would they (or wouldn't they) manifest.

A poorly organized low level system that is under even light shear from the west has the potential to form a new surface low under the dislocated convection.

This was mentioned several ago on this thread.

Potentially the shear might ease up later in the forecast according to some models, so if the storm hasn't been sheared inland over the peninsula in 4 days there is the possibility of a longer term event up near the central gulf coast.

Yes, it was, several times. Buy why does it form under the dislocated convection?

The dislocated convection draws moisture from the surface further east beneath it.
Often happens at night when the shear eases temporarily and the column of rising air feeds more directly from the warm surface below the convection.

So this repeating cycle of relocation may be what the GFS is expecting.

[CrazyC83]

This kinda reminds me of Cindy last year, and Bill in 2015. Could this drift all the way to SW LA or TX?

[Aric Dunn]

A poorly organized low level system that is under even light shear from the west has the potential to form a new surface low under the dislocated convection.

This was mentioned several ago on this thread.

Potentially the shear might ease up later in the forecast according to some models, so if the storm hasn't been sheared inland over the peninsula in 4 days there is the possibility of a longer term event up near the central gulf coast.

Yes, it was, several times. Buy why does it form under the dislocated convection?

The dislocated convection draws moisture from the surface further east beneath it.
Often happens at night when the shear eases temporarily and the column of rising air feeds more directly from the warm surface below the convection.

So this repeating cycle of relocation may be what the GFS is expecting.

All the models are indicating center reformations the difference is the direction of the shear..

[Aric Dunn]

This kinda reminds me of Cindy last year, and Bill in 2015. Could this drift all the way to SW LA or TX?

Same here.. I would not rule it out.

[AJC3]

Yes, it was, several times. Buy why does it form under the dislocated convection?

There can be two reasons. In a more tropical type setup, there is the combination of latent heat release aloft (the CISK process) and increasing VHT (vortical hot towers), that aid in the process of lowering surface pressures and increasing low level vorticity downshear. In a more dynamic/baroclinic (BE/BI) type setup such as this, you have strong jet divergence aloft, which leads to intense convection and lowering surface pressures downshear. Hope I wasn't too technical - it's not a terribly simple thing to explain.

[ronjon]

I wish wxman57 would give us his insight on 90L now since it’s looking like a north/central GOM issue now.

He did a couple of days ago. Basically going with the GFS idea that AJC3 has been discussing in his posts. Was thinking NE GOM somewhere along FL panhandle.

[Evil Jeremy]

00
ABNT20 KNHC 232308
TWOAT

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
710 PM EDT Wed May 23 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A broad surface low centered over the southeastern Yucatan
Peninsula has become better defined since yesterday, and it
continues to produce a large area of cloudiness and showers
extending from the northwestern Caribbean Sea across Cuba into the
Florida Straits. Continued slow development of this system is
possible during the next couple of days as it drifts northward near
the Yucatan Peninsula. Thereafter, environmental conditions are
forecast to become more conducive for development, and a subtropical
or tropical depression is likely to form this weekend over the
eastern or central Gulf of Mexico. Regardless of development,
locally heavy rainfall is possible across western Cuba and the
Cayman Islands during the next few days, and over much of Florida
and the northern Gulf Coast during the weekend. For more information
on the heavy rain threat, please see products issued by your local
weather office. The next Special Tropical Weather Outlook on this
system will be issued by 800 AM EDT on Thursday.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Beven

[cycloneye]

[robbielyn]

Well, this is interesting. Last night this now red area, which was orange last night is leaning toward the right from mobile all the way to big bend. Last night it was leaning straight up to a more definite central with no eastern leaning.

[DestinHurricane]

NHC development area well east, may be out of the woods in destin and locations farther west

[northjaxpro]

Definite lean. to the right by the NHC. Now up to 70% for development within 120 hours.

[Janie2006]

Alright, alright, alright. Back in the saddle for another season.

KMOB now has an "extreme risk" of flooding for Mobile and Baldwin counties in Alabama, Stone county in Southeast Mississippi, and Okaloosa and Santa Rosa counties in Northwest Florida. I cannot imagine that KLIX hasn't done the same for coastal Mississippi and Southeast Louisiana.

[Kazmit]

Code red for five days now. Also, they raised it to 10% for two days.

[toad strangler]

*image removed*

Climo this time of year agrees...