ATL: DEBBY - Post-Tropical - Discussion

[cycloneye]

A Tropical Storm Warning is now in effect for the southwest coast
of the Florida peninsula from East Cape Sable to Bonita Beach.

A Tropical Storm Watch is now in effect for the Florida Keys south
of the Card Sound Bridge including the Dry Tortugas, the southern
coast of the Florida peninsula east of East Cape Sable to the Card
Sound bridge, and for the west coast of the Florida peninsula north
of Bonita Beach to Aripeka.

[SouthFLTropics]

Call me confused but I cannot figure out why the NHC would issue a TS watch for the Keys and Dry Tortugas but a TS warning for the SW coast of the Florida peninsula. That doesn't seem to make a lot of sense. Impacts will be felt in the keys first.

[Hypercane_Kyle]

The angle-of-attack relative to the Florida coastline is really important. We're talking shifts over the current "best guess" for the center of 15-20 miles could mean a landfall as far south as Naples and a relative non-event, or further up the coastline and possibility increasing the time over water by a day.

[chaser1]

Moisture currently moving west in the Gulf of Mexico. Might delay a northern turn until that changes.
https://tropicwatch.info/moisturewest080220241300z.gif

Watching it over and over again, it’s hard for me to not think the center will be more south of the Cuba Coastline than what is being depicted. Looks like low will exit into the Gulf of Guacanayabo, moving W to WNW.

Of course, it’s my untrained eye and I could be incorrect.

Seems to me as well that center formation either occurs south of Central Cuba along the southern coastline, or the systems traverses nearly all of Cuba really throwing off the major models genesis timing by being further west given the prolonged journey reaching open water and delaying a more developed mid-level from feeling the tug northward. Either way, a more westward or a more southward genesis results in all prior model runs being thrown out the window given an inaccurate COC initialization. This is a fairly large lumbering system. These larger west moving systems are typically prone to slower reaction to less dramatic steering corrections. The other thing is we're not talking about a LLC trailing a 500mb center that is already on the north coast of Cuba where a new COC would magically pop up and redevelop under it. As long as the stronger mid-level vorticity remains over land moving around 285 degrees, than I have to think this will retard development by hours resulting in a genesis a bit further west and south than currently projected. How much that might change landfall intensity or short to mid-term track I'm not sure. If this were to develop over or just south of W. Cuba, than the chances of this reaching minimum hurricane intensity between Tampa and Tallahassee become a greater concern. That's my .02 cents worth anyway.

[fllawyer]

I agree with this. We will likely see tropical conditions tomorrow here in the Keys as most models suggest this will quickly consolidate over the Florida Straits within 36 hours likely bringing storm conditions by tomorrow.

I expect at least a tropical storm watch to be posted over the Florida Keys at the 11am update.

I do think this will catch people off guard tomorrow down here in the Keys. There is a reason why advisories are issued when tropical storm conditions are likely or expected.

Might get to see a lobster walk in advance of, and then after, the storm.

[wxman57]

Have very little time. I have 35kt TS into Tampa Bay in 48 hrs. NHC better get that PTC advisory going.

How much rain for me they are saying 10 inches

Not knowing where you are, I have no guess.

[chaser1]

So very happy that this won't have much time to organize. Yesterday we were unsure, but a weak tropical storm as wxman pointed out looks the most likely scenario.

I think this is still a low confidence call until we actually have a COC and there sure isn't much evidence for one developing over the north Cuba coastline..... yet.

[869MB]

After eyeballing some of the vorticity products and the upper & lower level winds, I can understand why the system is tilted to the west….the 925mb vorticity is slightly further east than the 500mb vorticity which is further west because the upper level winds between 100mb - 350mb are stronger out of the east as compared to the winds between 700mb - 925mb.

Therefore, I think the overall circulation will get slightly tugged a little further west than most models are currently depicting. If this is the case, the overall consolidation of the ultimate center of the storm may organize slightly west or even west/southwest of current expectations, which may slightly delay a gain in latitude in the short term, which in turn may ultimately affect the long term Mid-Atlantic trough interaction.

In other words, a further west or west-southwest consolidation would possibly increase a long term stalling scenario somewhere in the NE Gulf/Florida/Georgia vicinity due to limited trough interaction (The trough lifting out without fully capturing the cyclone).

Just my two cents…We shall see.

[Jr0d]

The angle-of-attack relative to the Florida coastline is really important. We're talking shifts over the current "best guess" for the center of 15-20 miles could mean a landfall as far south as Naples and a relative non-event, or further up the coastline and possibility increasing the time over water by a day.

Just a slight shift 'left' in the forecast track can make a huge difference no doubt. Also if it gets extra time over water with the barocyclonic forcing, I would expect a much stronger system than currently forecast at landfall on the west coast of Florida.

Of course if it goes right or further east of the forecast we will likely only see a minimum storm over Florida...

[wxman57]

My track is about 20 miles east of NHC's, taking the center into the coast west of Tampa Bay 10am Sunday with 35 kts. NHC has about 6 hours more over water. With a storm paralleling the coast, a small heading change can make the difference between Big Bend and Ft. Myers. These type of storms tend to trend right rather than left. I think NHC will adjust their track to the right later.

Who would have thought that the NHC would start PTC advisories this morning?

[chaser1]

My thoughts this morning.

 https://x.com/NDGMETCHEF/status/1819351266612429155

Same here; off by .5 - 1.0 degree (perhaps slightly more)

[Stormlover70]

Have very little time. I have 35kt TS into Tampa Bay in 48 hrs. NHC better get that PTC advisory going.

How much rain for me they are saying 10 inches

Not knowing where you are, I have no guess.

New Port Richey

[DunedinDave]

A bit of a side note but it seems like the last 3-5 years, we’ve been seeing more storms come from the Cuba region and head into the eastern Gulf. Irma, Ian, Idalia, Eta just to name a few.

For a long stretch there it was more northern gulf coast focused from Louisiana to Pensacola with storms tending to move more N and NW in the gulf. The trend has been more N and NE it seems.

Maybe it’s just me but from living in Tampa all my life it seems the last 5 years the west coast has been more active.

[Stormlover70]

Call me confused but I cannot figure out why the NHC would issue a TS watch for the Keys and Dry Tortugas but a TS warning for the SW coast of the Florida peninsula. That doesn't seem to make a lot of sense. Impacts will be felt in the keys first.

because it might not be developed yet in that area.

[StPeteMike]

How much rain for me they are saying 10 inches

Not knowing where you are, I have no guess.

New Port Richey

Hard to tell. If it stays on the NHC track, I would say around 4 inches - 6 inches. A stronger storm, little further west annd over open waters, and possibly missing the trough catching it and meandering in the NE Gulf or North Florida, the totals could likely be more.

Sunday and Monday will be a washout, no matter what. Except…. if it goes into Naples lol

[Stormlover70]

A bit of a side note but it seems like the last 3-5 years, we’ve been seeing more storms come from the Cuba region and head into the eastern Gulf. Irma, Ian, Idalia, Eta just to name a few.

For a long stretch there it was more northern gulf coast focused from Louisiana to Pensacola with storms tending to move more N and NW in the gulf. The trend has been more N and NE it seems.

Maybe it’s just me but from living in Tampa all my life it seems the last 5 years the west coast has been more active.

new Port Richey here and I agree

[Michele B]

My track is about 20 miles east of NHC's, taking the center into the coast west of Tampa Bay 10am Sunday with 35 kts. NHC has about 6 hours more over water. With a storm paralleling the coast, a small heading change can make the difference between Big Bend and Ft. Myers. These type of storms tend to trend right rather than left. I think NHC will adjust their track to the right later.

Who would have thought that the NHC would start PTC advisories this morning?

I don't like when storms are predicted to attack Tampa.

My experience has been that they never actually get that far north. They seem to like the Peace River and detour in that direction, which brings it to my neck of the woods. With that in mind, I won't be taking my eyes off this one till it's gone out into the Atlantic.

[MetroMike]

My track is about 20 miles east of NHC's, taking the center into the coast west of Tampa Bay 10am Sunday with 35 kts. NHC has about 6 hours more over water. With a storm paralleling the coast, a small heading change can make the difference between Big Bend and Ft. Myers. These type of storms tend to trend right rather than left. I think NHC will adjust their track to the right later.

Who would have thought that the NHC would start PTC advisories this morning?

I think you called it and some posters here poo pooed that idea.

[Michele B]

A bit of a side note but it seems like the last 3-5 years, we’ve been seeing more storms come from the Cuba region and head into the eastern Gulf. Irma, Ian, Idalia, Eta just to name a few.

For a long stretch there it was more northern gulf coast focused from Louisiana to Pensacola with storms tending to move more N and NW in the gulf. The trend has been more N and NE it seems.

Maybe it’s just me but from living in Tampa all my life it seems the last 5 years the west coast has been more active.

I agree with you! Grew up in Miami, and we saw a hurricane or threats of hurricane just about every year!

In the past few years, living nearer to the west coast of FL, it seems ALL the storms are coming this way, and most of what happens on the east coast is just rain (including flooding), but no actual hurricane threats.

[Jr0d]

Moisture currently moving west in the Gulf of Mexico. Might delay a northern turn until that changes.
https://tropicwatch.info/moisturewest080220241300z.gif

Watching it over and over again, it’s hard for me to not think the center will be more south of the Cuba Coastline than what is being depicted. Looks like low will exit into the Gulf of Guacanayabo, moving W to WNW.

Of course, it’s my untrained eye and I could be incorrect.

That is what I am seeing, a possible circulation right around the Gulf of Guacanayabo. Of course with developing systems there are often several low level vortices so I am not sure if it's a temporary feature or the actual center of low pressure.
https://weather.cod.edu/satrad/?parms=m ... =undefined