ATL: DEBBY - Post-Tropical - Discussion

[weeniepatrol]

This is becoming extremely uncomfortable. From the last discussion.. six hours ago:

INIT 02/2100Z 21.4N 78.3W 25 KT 30 MPH...POTENTIAL TROP CYCLONE

12H 03/0600Z 22.4N 80.1W 25 KT 30 MPH...POTENTIAL TROP CYCLONE

24H 03/1800Z 24.2N 82.2W 30 KT 35 MPH...TROPICAL CYCLONE

Slow development is possible while the system is over Cuba, and the system is likely to become a tropical depression soon after it moves offshore on Saturday.

Just six hours ago this was forecast to become a depression AFTER emergence into the Gulf, around 18 zulu tomorrow. In other words, this is a whopping ~18 hours ahead of schedule.. AND as the new discussion mentioned with the west shift will have even MORE time over the 86-90 F waters of the Gulf of Mexico than initially forecast. This is very serious.

The biggest factor I was worried about was the location being over water. It simply consolidated south over the most favorable environment. Hopefully passage over Cuba will prevent any RI in the short term. I don’t trust anything organized coming into the gulf with those record water temps ahead and low shear. In the long term there might be some shear and dry air that caps it before landfall as Levi pointed out.

The issue with that is:

1. We've seen systems not be disrupted whatsoever by passage over western Cuba time and time again, such as Ian.

2. In Levi's video, look at what ECMWF shows. 1007mb Sunday afternoon? At this rate this will be 1007mb within 12 hours

[MGC]

Didn't expect the upgrade so soon.....I also would not be surprised to see additional westward track adjustments......MGC

[Poonwalker]

This is becoming extremely uncomfortable. From the last discussion.. six hours ago:

INIT 02/2100Z 21.4N 78.3W 25 KT 30 MPH...POTENTIAL TROP CYCLONE

12H 03/0600Z 22.4N 80.1W 25 KT 30 MPH...POTENTIAL TROP CYCLONE

24H 03/1800Z 24.2N 82.2W 30 KT 35 MPH...TROPICAL CYCLONE

Slow development is possible while the system is over Cuba, and the system is likely to become a tropical depression soon after it moves offshore on Saturday.

Just six hours ago this was forecast to become a depression AFTER emergence into the Gulf, around 18 zulu tomorrow. In other words, this is a whopping ~18 hours ahead of schedule.. AND as the new discussion mentioned with the west shift will have even MORE time over the 86-90 F waters of the Gulf of Mexico than initially forecast. This is very serious.

The biggest factor I was worried about was the location being over water. It simply consolidated south over the most favorable environment. Hopefully passage over Cuba will prevent any RI in the short term. I don’t trust anything organized coming into the gulf with those record water temps ahead and low shear. In the long term there might be some shear and dry air that caps it before landfall as Levi pointed out.

The issue with that is:

1. We've seen systems not be disrupted whatsoever by passage over western Cuba time and time again, such as Ian.

2. In Levi's video, look at what ECMWF shows. 1007mb Sunday afternoon? At this rate this will be 1007mb within 12 hours

Yeah the models were trying to initiate a wave that was over land though. They can’t handle intensity forecasts without a formed COC. The only useful info was the track but they were starting too far north. The ones to watch for intensity at this time will be the HWRF, HAPS, and Ships. GFS next and then the Euro.

[weeniepatrol]

Yeah the models were trying to initiate a wave that was over land though. They can’t handle intensity forecasts without a formed COC. The only useful info was the track but they were starting too far north. The ones to watch for intensity at this time will be the HWRF, HAPS, and Ships. GFS next and then the Euro.

That is true, but I think we agree we can expect a much deeper system than that as it approaches landfall, meaning it will be more resilient to said shear and dry air.

[Hurricane Mike]

1130pm video update on TD 4
https://www.youtube.com/watch?v=y51QN9gDeLA

[stormhunter7]

Looks like new hot tower going up near center. I also see two more convection towers going up near the center. I think the low level center may still be west of the track?

[AtlanticWind]

Still kinda disorganized, land interaction will probably keep
a lid on this until it can clear cuba.

[TallyTracker]

We’re stocked up and ready for the storm. I’m mowing the lawn and cleaning out the French drains tomorrow. Then we’ll hunker down here in Tallahassee. My main concern is rapid development sending this above a Cat 1.

[TomballEd]

The center still seems to be moving barely N of due W, I buy the NHC's advisory 285* heading. It should turn NW immediately to follow the center of the NHC cone.

[AtlanticWind]

Looks like it may be about to start its journey over Cuba ,seems to be slowly making its NW turn

[chaser1]

I see no course correction thus far. Slower perhaps, but nothin' but west motion

[AtlanticWind]

It’s looks to me like the circulation is on north side of convection approaching the Cuban coast

[USTropics]

Radar loop sped up a bit does a good job of tracking the center for now:



https://www.barbadosweather.org/Composite/kidbuuComposite_Lionel_displayer2.php?Product=Reflectivity&Sector=NW_Caribbean&Composite=Sabre&ANISP=700&MAPP=1&PlanetOfTheApes=908241.9776540145

[Hurrilurker]

Looks like a pretty big jump to the NW. That's good because it might not travel over the narrowest, flattest part of PR, and will have less time in the Gulf to organize.

[AtlanticWind]

5pm advisorie has it almost on the Cuban shoreline
Should begin its short trek over Cuba this morning

[caneman]

5pm advisorie has it almost on the Cuban shoreline
Should begin its short trek over Cuba this morning

I saw that NW movement a few hours ago as well. Think the models will stop moving west now and perhaps tic back East some. IMO.

[GCANE]

The up-draft anti-cyclone disappeared for a while but is now back.
Centered well south of Cuba at 20N 81.1W

[GCANE]

A Hurricane Watch is in effect for...
* Aucilla River to Yankeetown

https://www.nhc.noaa.gov/text/refresh/M ... 1131.shtml

[NDG]

This morning TD 4 seems to be not aligned with its MCL, perhaps some SE shear going on at the low levels.

 https://x.com/NDGMETCHEF/status/1819702344277254541

[Michele B]

I still believe once this system gets out into the Gulf ALL earlier intensity forecasts and future track cones go out the window. It sure is moving slow.

The Bermuda high is strong, but is Four going to miss the dip in the jet stream that’s supposed to pick it up and steer it north/NE?