ATL: IDA - Remnants - Discussion

[weeniepatrol]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
505 AM EDT Thu Aug 26 2021

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

Special tropical weather outlook issued to update the discussion of
the system south of Jamaica.

Updated: Shower and thunderstorm activity continues to become better
organized in association with a trough of low pressure located less
than 200 miles south of Jamaica. Environmental conditions remain
conducive for development, and a tropical depression or storm is
expected to form later today or tomorrow. This system is forecast to
move northwestward over the northwestern Caribbean Sea near the
Cayman Islands tonight, near Cuba and the Yucatan Peninsula of
Mexico on Friday, and into the Gulf of Mexico this weekend. Given
the recent developmental trends, Tropical Storm Warnings for the
Cayman Islands and Tropical Storm Watches for western Cuba could be
required later today.

Regardless of development, locally heavy rainfall and flooding will
be possible over portions of Jamaica and the Cayman Islands today
and tonight, and will likely spread across Cuba and the Yucatan
Peninsula on Friday. In addition, this system could bring dangerous
impacts from storm surge, wind, and heavy rainfall to portions of
the coasts of Louisiana, Texas, and the Mexican state of Tamaulipas
late this weekend and early next week. However, uncertainty remains
large since the system has yet to form. Interests in these areas
should closely monitor the progress of this system and ensure they
have their hurricane plan in place. An Air Force Reserve
reconnaissance aircraft is scheduled to investigate the system later
today, if necessary. Additional information on this system,
including gale warnings, can be found in High Seas Forecasts issued
by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

[Kohlecane]

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
505 AM EDT Thu Aug 26 2021

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

Special tropical weather outlook issued to update the discussion of
the system south of Jamaica.

Updated: Shower and thunderstorm activity continues to become better
organized in association with a trough of low pressure located less
than 200 miles south of Jamaica. Environmental conditions remain
conducive for development, and a tropical depression or storm is
expected to form later today or tomorrow. This system is forecast to
move northwestward over the northwestern Caribbean Sea near the
Cayman Islands tonight, near Cuba and the Yucatan Peninsula of
Mexico on Friday, and into the Gulf of Mexico this weekend. Given
the recent developmental trends, Tropical Storm Warnings for the
Cayman Islands and Tropical Storm Watches for western Cuba could be
required later today.

Regardless of development, locally heavy rainfall and flooding will
be possible over portions of Jamaica and the Cayman Islands today
and tonight, and will likely spread across Cuba and the Yucatan
Peninsula on Friday. In addition, this system could bring dangerous
impacts from storm surge, wind, and heavy rainfall to portions of
the coasts of Louisiana, Texas, and the Mexican state of Tamaulipas
late this weekend and early next week. However, uncertainty remains
large since the system has yet to form. Interests in these areas
should closely monitor the progress of this system and ensure they
have their hurricane plan in place. An Air Force Reserve
reconnaissance aircraft is scheduled to investigate the system later
today, if necessary. Additional information on this system,
including gale warnings, can be found in High Seas Forecasts issued
by the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

Well I would imagine we get a PTC designation out of that come 11AM

[cycloneye]

 https://twitter.com/AndyHazelton/status/1430840931696054272

[GCANE]

Looks like this may have shifted quite a bit north east from where recon was planning to fly to today.

[GCANE]

ULL to the west slowly weakening.
700mb vort strengthening and beginning to cut off.

[GCANE]

The weakening of the ULL is taking out a ton of shear

[GCANE]

Looks like areas east of the MS Delta may be under the gun now.

[MississippiWx]

I believe we already have a tropical depression consolidating nearly over Jamaica. I’m amazed to find it ramping up even further north than yesterday. Places like NOLA and the MS Coast should be on high alert as the newest GFS run shows.

[Shell Mound]

 https://twitter.com/BMcNoldy/status/1430840243066863617

[aspen]

This looks to be consolidating way NE of where most models expected it to be around now. However, without ASCAT or recon at the moment, it’s difficult to be certain, and center jumps are still possible. Seems like a Cuba landfall is highly likely though.

[GCANE]

A major shift for 00Z GFS.
Looks like a weak ML HIgh over the Carolina's seaboard will be the major feature steering this in the GoM.
Forget about the EPAC TC in terms of shear or steering effects.
Track moving east and getting close to a high CAPE pool off FL Big Bend.
Will be under a huge UL HIgh and anticyclone.
Not looking pretty for NoLA, AL, FL Panhandle

[AlphaToOmega]

Given the recent developmental trends, Tropical Storm Warnings for the Cayman Islands and Tropical Storm Watches for western Cuba could be required later today.

[GCANE]

This is what I was afraid of.
Just checked the model progression of the Rossby Wave.
Run to run shows it digging south.
Looks likely now forecasted intensity will increase in the GoM and track shifting more east.
Temps are cooling in the CONUS Midwest with rain coming in.
That'll keep pushing that Rossby wave further south in the forecasts.

[GCANE]

Needless to say, the first recon run today will be very significant

[GCANE]

Ouch!!
Right in the middle of a 355K PV Ring as it enters the GoM

[aspen]

Ouch!!
Right in the middle of a 355K PV Ring as it enters the GoM

[url]https://i.postimg.cc/XJvScVMK/gfs-pv355-K-atl-9.png [/url]

What will that do?

[Jagno]

These drastic model flip flops will ultimately catch people totally off guard. Please do not relax your preparations anywhere from Texas to Florida.

[Shell Mound]

Ouch!!
Right in the middle of a 355K PV Ring as it enters the GoM

https://i.postimg.cc/XJvScVMK/gfs-pv355-K-atl-9.png

Unless 99L is somehow sufficiently strong, the PVS just to its west would still induce westerly shear, thus limiting intensification over the Gulf. The PVS is attributable to downstream wave fluxes associated with TD Fourteen's convection over the EPAC near the west coast of Mexico. This PVS will play a major role in 99L's ultimate intensity. A stronger 99L prior to western Cuba would be better able to offset westerly shear from TD Fourteen.

[3090]

These drastic model flip flops will ultimately catch people totally off guard. Please do not relax your preparations anywhere from Texas to Florida.

No area should let their guard down. That is a given. However, it is looking less likely for Texas and Florida. More likely for all of Louisiana and possibly Mississippi and Alabama, both being to the immediate east of landfall.

[jlauderdal]

These drastic model flip flops will ultimately catch people totally off guard. Please do not relax your preparations anywhere from Texas to Florida.

No area should let their guard down. That is a given. However, it is looking less likely for Texas and Florida. More likely for all of Louisiana and possibly Mississippi and Alabama, both being to the immediate east of landfall.

The panhandle is in Florida and the chances are increasing there with each model run.