ATL: ISAIAS - Post-Tropical - Discussion

[chaser1]

This is the track I am thinking

https://i.imgur.com/5VtfTqX.jpg

Not at all unreasonable

[SFLcane]

Can't recall the last time I've seen so much disagreement for a non-cyclone. It's heading west. It's clearly going WNW. Convection is bouncing NW. It's an open wave. It's about to close off. North of Hispaniola. South of Hispaniola. Shear and dry air will kill it North of the islands. The heat content is ripe for intensification. Florida can take a nap now. Florida's got to keep it's eyes open.

Man, I can only imagine what the NHC has been debating internally for the past week. I'm still in awe at Stewart's excellent discussion from last night. I can only wonder what Avila's rebuttal would have been...

I think we can all agree that we are lucky this system's gargantuan footprint and fast pace across the Atlantic prevented what could have been a much worse situation for the NE Caribbean today.

Well its the Atlantic basin. Sometimes the stars and the moon have to align in order to a get a well organized TC. Fragile basin

[Hurricaneman]

Eric Blake seemed to disagree with Stewart this morning:

The cyclone will probably take some time to recover after
moving over the very high mountains of Hispaniola, and some of the
guidance after that time shows an increase in southwesterly shear
over the Straits of Florida that could limit the potential of the
cyclone. Simply put, there are a lot of hurdles in the system's
way, so it is best to stay on the conservative side at the moment
and continue to stress the large uncertainty after it leaves the
Caribbean. Little change was made to the forecast intensity,
although the guidance has come down at longer range for many of the
models.

It even seems the pros at the NHC are arguing what this will do, it’s not very common

[chaser1]

I think you can pretty much scratch FL off the list.
Start thinking more about the West Carib / GoM

That's precious

[AubreyStorm]

Time: 14:18:00Z
Coordinates: 16.633N 64.717W
Acft. Static Air Press: 923.1 mb
Acft. Geopotential Hgt: 785 m (2,575 ft)
Extrap. Sfc. Press: 1009.6 mb (29.82 inHg)
Flt. Lvl. Wind (30s): From 45° at 37 kts (From the NE at 42.6 mph)
Air Temp: 21.6°C (70.9°F)
Dew Pt: 19.5°C (67.1°F)
Peak (10s) Flt. Lvl. Wind: 38 kts (43.7 mph)
SFMR Peak (10s) Sfc. Wind: 30 kts (34.5 mph)
SFMR Rain Rate: 0 mm/hr

[GCANE]

I think you can pretty much scratch FL off the list.
Start thinking more about the West Carib / GoM

Florida does have a coastline along the Gulf of Mexico ya know

Dang, your right.
Forgot about that part.

[ScottNAtlanta]

The problem you have getting a west wind in the Eastern Caribbean is that the winds surge from the east and its hard to get a west wind until you get to the Western Caribbean and they slow down. A weaker system gets trapped in the easterly flow. Although, some have mentioned that the trades are not as brisk in the area right now.

[Javlin]

Looking at MIMIC this one rolls W for while and either impacts CA or the trough over the US lifts it some?This has been the main steering for the last month.

http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

[wxman57]

Can't recall the last time I've seen so much disagreement for a non-cyclone. It's heading west. It's clearly going WNW. Convection is bouncing NW. It's an open wave. It's about to close off. North of Hispaniola. South of Hispaniola. Shear and dry air will kill it North of the islands. The heat content is ripe for intensification. Florida can take a nap now. Florida's got to keep it's eyes open.

Man, I can only imagine what the NHC has been debating internally for the past week. I'm still in awe at Stewart's excellent discussion from last night. I can only wonder what Avila's rebuttal would have been...

I think we can all agree that we are lucky this system's gargantuan footprint and fast pace across the Atlantic prevented what could have been a much worse situation for the NE Caribbean today.

I must disagree with you.

[HurricaneFrances04]

INIT 29/1500Z 15.8N 63.7W 40 KT 45 MPH...POTENTIAL TROP CYCLONE
12H 30/0000Z 16.9N 66.4W 45 KT 50 MPH...TROPICAL CYCLONE
24H 30/1200Z 18.5N 69.8W 50 KT 60 MPH
36H 31/0000Z 19.9N 73.0W 40 KT 45 MPH...INLAND
48H 31/1200Z 21.4N 76.0W 40 KT 45 MPH...NEAR COAST
60H 01/0000Z 22.7N 78.3W 40 KT 45 MPH...OVER WATER
72H 01/1200Z 23.8N 80.2W 45 KT 50 MPH
96H 02/1200Z 26.3N 82.6W 45 KT 50 MPH
120H 03/1200Z 29.0N 83.5W 45 KT 50 MPH

[wxman57]

Matches my track last hour, but I have it as a TD or remnant low near Florida. Nothing indicates TS in Gulf or near west Florida. NHC is being cautious so that people pay attention. That's their job. Staying a TS after crossing the DR, interacting with Cuba, and fighting the mid-level dry air and shear? Maybe a little optimistic.

[Evil Jeremy]

Discussion highlights:

"It still must be
stressed that since the system lacks a well-defined center and
remains in its formative stage, uncertainty in the specifics of the
track forecast remain high in both the short and longer range. The
latest NHC track foreast has been nudged slightly south of the
previous advisory and lies between the latest ECMWF solution and the
various consensus aids."

"Some additional
intensification is then possible before the system reaches
Hispaniola on Thursday, but weakening is likely to occur while it
interacts with land. After that time, the system's close proximity
to eastern Cuba and an expected increase in southwesterly shear are
likely to inhibit significant re-strengthening."

[ScottNAtlanta]

My thoughts exactly...

 https://twitter.com/webberweather/status/1288483748196036608

[SFLcane]

Winds reduced to your daily afternoon storms "50 mph" in Florida. Not much hope anything will be left other then some rain for SFL. Enjoy your haircut PT9.

[gatorcane]

I would pay attention to the Northern side of this wave. That is where some models want to develop the low-level center which could still end up just north of Hispaniola. We can even see some center reformations to the north as the wave interacts with land.

[GCANE]

I asked this when this was at 40W:
What is going to cause this to turn NW?
Question still stands.

GFS currently has it as a closed surface low - NOT.

[supercane4867]

I'm thinking the upcoming interaction with Hispaniola could help to trim its size. Probably will cut the massive circulation in half as the GFS and GFS parallel run suggest. In the most interesting scenario it may end up with 2 TCs: one in the western Caribbean and one in the Bahamas.

[jfk08c]

I asked this when this was at 40W:
What is going to cause this to turn NW?
Question still stands.

GFS currently has it as a closed surface low - NOT.

Beta drift will eventually cause the turn

[HurricaneFrances04]

I would pay attention to the Northern side of this wave. That is where some models want to develop the low-level center which could still end up just north of Hispaniola. We can even see some center reformations to the north as the wave interacts with land.

Can see that on the latest ICON, but also seen it in other models as well:

[GCANE]

I asked this when this was at 40W:
What is going to cause this to turn NW?
Question still stands.

GFS currently has it as a closed surface low - NOT.

Beta drift will eventually cause the turn

Only when it spins up fast enough.