ATL: TWENTY-ONE - Remnants - Discussion

[Subtrop]

AL, 95, 2023102206, , BEST, 0, 113N, 814W, 30, 1008, LO, 34, NEQ, 0, 0, 0, 0, 1010, 200, 80, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 041, SPAWNINVEST, al762023 to al952023,

https://ftp.nhc.noaa.gov/atcf/btk/bal952023.dat

[ElectricStorm]

Pretty nice burst of convection. Doesn't have much time at all but maybe it can try to spin up into a TD

[cycloneye]

Southwestern Caribbean Sea (AL95):
Showers and thunderstorms have become better organized in
association with a low pressure system located over the southwestern
Caribbean Sea. Gradual development of this system is possible, and
a tropical depression could form before the system moves inland over
Nicaragua by early Tuesday. Regardless of development, this system
could produce heavy rains over portions of Central America during
the next couple of days.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 7 days...medium...50 percent.

[Sciencerocks]

[MarioProtVI]

Models are way too aggressive with this. GFS HWRF HMON and HAFS A and B make this a hurricane by tomorrow - impossible with its current structure. Euro is a much more likely scenario - weak and broad/barely becomes a TD before moving inland. Current satellite imagery shows a broad area of spin and I can’t see that spinning up as fast as the other models do.

[zhukm29]

Models are way too aggressive with this. GFS HWRF HMON and HAFS A and B make this a hurricane by tomorrow - impossible with its current structure. Euro is a much more likely scenario - weak and broad/barely becomes a TD before moving inland. Current satellite imagery shows a broad area of spin and I can’t see that spinning up as fast as the other models do.

One thing to note is that the curvature of the Nicaraguan coast line and frictional convergence can help tighten up a system like this very quickly - we've seen this happen quite often during the past few seasons with storms rapidly organizing on the coast. Might not be a hurricane like most of the models you mentioned, but personally I think the outcome will be somewhat of a middle ground between the GFS and Euro (probably a low-to-medium strength TS during landfall).

[Nimbus]

Ridging to the north might take this into Central America before it becomes an issue?

[zzzh]

GFS initialized the system too strong

[floridasun]

Ridging to the north might take this into Central America before it becomes an issue?

we move into central america

[Dean_175]

Wow, starting to think there is a real possibility they could end up having to use the new auxiliary list this year and have our second named A storm. During an El Nino year.

[Sciencerocks]

I think a minimum tropical storm is the highest this becomes...35 knts. This has probably 24 hours at most. If I had to guess I'd think the nhc will probably lean conservative and simply not upgrade unless it manages to develop a well defined LLC overnight into tomorrow...We will see! The center looks to be about 80 nmi's of the coast or ~83.5 west or so...



Of course we could be shocked and see this come in stronger like the models suggest. lol

[zhukm29]

Just so happens that ASCAT (not surprisingly) missed the system. Guess it's becoming more likely we might not end up getting ASCAT for this, which will make designation harder, especially with no recon.

Kind of annoying that ASCAT B and C pretty much sample the same area, so if one misses, the other misses as well and they always miss whenever you really want them to hit lol. Going to hope that one pass manages to hit before this makes landfall, but considering ASCAT managed to miss pre-Sean for like 3 days straight, I'm not too optimistic.

[Sciencerocks]

[abajan]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Mon Oct 23 2023

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

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Tammy, located a few hundred miles north of the northern Leeward
Islands.

Southwestern Caribbean Sea (AL95):
Showers and thunderstorms continue to show signs of organization in
association with a low pressure system located over the southwestern
Caribbean Sea. Environmental conditions appear to be favorable for
development, and a short-lived tropical depression could form before
the system moves inland over Nicaragua by early Tuesday. Regardless
of development, this system could produce heavy rains over portions
of Central America during the next couple of days.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...medium...60 percent.

$$
Forecaster Cangialosi/Bucci

[MarioProtVI]

Very disorganized at low levels. Don’t see this developing at all. It’s just about out of time and will move inland later tonight early tomorrow. Euro was correct in keeping this broad and weak and not developing it. Main threat will be mudslides and heavy rain.

[Sciencerocks]

[cycloneye]

Southwestern Caribbean Sea (AL95):
Satellite data indicate that the area of low pressure located over
the southwestern Caribbean Sea has developed a well-defined center.
In addition, the associated showers and thunderstorms continue to
show signs of organization. If the current trends continue,
advisories could be initiated later this afternoon or evening on a
short-lived tropical depression. The low is expected to move inland
over Nicaragua by early Tuesday and will likely produce heavy rains
over portions of Central America during the next couple of days.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...80 percent.

[ChrisH-UK]

95L is improving quick, a good deal of spin and tons of convection should get organised fairly soon. An interesting note Nicaragua rarely gets hits by tropical storms but has Hurricanes fairly often during october.

[zzzh]

Very disorganized at low levels. Don’t see this developing at all. It’s just about out of time and will move inland later tonight early tomorrow. Euro was correct in keeping this broad and weak and not developing it. Main threat will be mudslides and heavy rain.

This is organized

[underthwx]

I haven't kept up very well with 95L...is the system stationary?