ATL: IDA - Remnants - Discussion

[cycloneye]

SSD dvorak.

A. TROPICAL DISTURBANCE (99L)

B. 25/2330Z

C. 14.5N

D. 75.8W

E. FIVE/GOES-E

F. T1.5/1.5

G. IR/EIR/SWIR

H. REMARKS...CIRCULAR CLOUD LINES AROUND A CSC THAT IS LESS THAN 1.25
DEGREES FROM A SMALL COLD OVERCAST MAKES THE DT EQUAL TO 1.5 USING THE
SHEAR PATTERN. THE MET IS EQUAL TO 1.0 AND THE PT AGREES WITH THE DT
AND IS ALSO EQUAL TO 1.5. THE FT IS BASED ON THE PT DUE TO CONVECTION
THAT HAS NOT BEEN PERSISTENT NEAR THE CSC IN RECENT SATELLITE IMAGERY.

I. ADDL POSITIONS

NIL


...SAMBUCCI

[GCANE]

Looks like the only towers firing at this point is far removed from the LLC indicated by IR Sat analysis.
Makes sense since AMSU is showing a very small warm core with a thermal inversion near the surface keeping lapse rate minimal.
Once a cold pool forms, the lid comes off and convection should fire much closer to the LLC.
Would hate to see this turn into a pinhole.

[BobHarlem]

The 8PM Outlook was "Corrected" to 60/80 (was 50/80)

[AlphaToOmega]

A broad area of low pressure is expected to form over the western
Caribbean Sea during the next day or so from a tropical wave
currently located north of Colombia. Environmental conditions are
forecast to be conducive for development, and a tropical depression
or tropical storm is likely to form late this week or over the
weekend. The system is expected to move northwestward over the
northwestern Caribbean Sea and near or across the Yucatan Peninsula
of Mexico on Friday and into the Gulf of Mexico this weekend, where
conditions are expected to be favorable for additional development.
Regardless of development, heavy rainfall and flooding will be
possible through the weekend in portions of Central America and the
Yucatan Peninsula. 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
Thursday afternoon, if necessary.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

[sma10]

Do you think maybe it's getting pretty close to NHC to consider putting up PTC advisories?

[jlauderdal]

This has a good shot to be the storm of the season.

[captainbarbossa19]

A broad area of low pressure is expected to form over the western
Caribbean Sea during the next day or so from a tropical wave
currently located north of Colombia. Environmental conditions are
forecast to be conducive for development, and a tropical depression
or tropical storm is likely to form late this week or over the
weekend. The system is expected to move northwestward over the
northwestern Caribbean Sea and near or across the Yucatan Peninsula
of Mexico on Friday and into the Gulf of Mexico this weekend, where
conditions are expected to be favorable for additional development.
Regardless of development, heavy rainfall and flooding will be
possible through the weekend in portions of Central America and the
Yucatan Peninsula. 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
Thursday afternoon, if necessary.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

Interesting choice of words.

[Ubuntwo]

Do you think maybe it's getting pretty close to NHC to consider putting up PTC advisories?

Based on the 18z model suite, 99L could qualify for PTC advisories by 11PM, but I imagine they'll wait a little longer than that.

[sma10]

Do you think maybe it's getting pretty close to NHC to consider putting up PTC advisories?

Based on the 18z model suite, 99L could qualify for PTC advisories by 11PM, but I imagine they'll wait a little longer than that.

I agree with you. But if I lived in the Caymans or western Cuba, I'd keep a wary eye out

[cycloneye]

00z Best Track up in latitud.

AL, 99, 2021082600, , BEST, 0, 140N, 770W, 30, 1006, DB

[Keldeo1997]

 https://twitter.com/weather_chest/status/1430692241434189825

[wxman57]

Do you think maybe it's getting pretty close to NHC to consider putting up PTC advisories?

NHC procedure is to have a high chance of development (70% or more) within 48 hours and require the issuance of TS watches for a PTC to be declared and advisories started. Don't know how much I'll be around next 4-5 days. Starting back on 12-hr+ shifts tomorrow at 4:30am.

[zal0phus]

Is there any way of telling just yet how large this storm could be physically?

[wxman57]

Is there any way of telling just yet how large this storm could be physically?

Models suggest average size, as does current moisture envelope. TS winds going out maybe 130-150 miles east of the track. Hurricane force winds maybe 25-35 miles east of the center. Maybe a little larger.

[skyline385]

Is there any way of telling just yet how large this storm could be physically?

You can look at the Simulated IR on GFS(https://www.tropicaltidbits.com/analysi ... 82518&fh=6) or HWRF(https://www.tropicaltidbits.com/analysi ... 2518&fh=30) to get an idea.

It wont be a small storm for sure cause its part of a large trough and is pulling moisture from the EPAC.

[wxman57]

By the way, 00Z Consensus came in (TVCN) with landfall east of Vermilion Bay before sunrise on Monday.

[Stormgodess]

Local Baton Rouge Meteorologist just put this out there

https://ibb.co/JnZPPQG

Cant remember how to do images or either its not working for some reason

Just found it on Twitter too...

 https://twitter.com/Jay_WAFB/status/1430678148677578753

[grapealcoholic]

Newest tower is close to 18z gfs vortmax

[Nimbus]

Last GFS run I saw had a large UL High forming in the GOM when this is going to be in the middle of the GOM.
Not going in the right direction to keep a lid on this.
Right now, showing marginal CAPE in the east GOM, which would be a good thing.
Let's see what 00Z GFS shows tomorrow.

Deep layer steering with a pumped ridge could explain the track changes.
We need to see a few runs with a stable pattern for the upper air steering though.
And they will probably fly G-IV upper air missions in the gulf if this gets under a dome and slows down.

[Stormgodess]

Is there any way of telling just yet how large this storm could be physically?

You can look at the Simulated IR on GFS(https://www.tropicaltidbits.com/analysi ... 82518&fh=6) or HWRF(https://www.tropicaltidbits.com/analysi ... 2518&fh=30) to get an idea.

It wont be a small storm for sure cause its part of a large trough and is pulling moisture from the EPAC.

Anyone have a good image of current surface temps of the Gulf?