ATL: INVEST 93L - Discussion

[cycloneye]

AL, 93, 2023100918, , BEST, 0, 199N, 947W, 25, 1009, LO, 34, NEQ, 0, 0, 0, 0, 1012, 120, 50, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 039, SPAWNINVEST, al742023 to al932023,

https://ftp.nhc.noaa.gov/atcf/btk/bal932023.dat

Thread that was the topic for this area at Talking Tropics forum.

https://www.storm2k.org/phpbb2/viewtopi ... 5#p3051035

[Sciencerocks]

[ElectricStorm]

I would assume shear from Lidia will keep this from doing much. Doesn't look terrible right now though. Maybe an outside chance at a short-lived TD but most likely not.

[WalterWhite]

It only has a 20% chance of development, according to the NHC. Why is the NHC already calling this an invest?

[abajan]

It only has a 20% chance of development, according to the NHC. Why is the NHC already calling this an invest?

Possibly due to its proximity to populated areas. It may also produce significant rainfall.

[tolakram]

It only has a 20% chance of development, according to the NHC. Why is the NHC already calling this an invest?

Because they want to? So Hurricane models will run for it? To prepare for a PTC if they feel winds will be strong enough to warn for?

[cycloneye]

8 PM:

Southwestern Gulf of Mexico (AL93):
A broad area of low pressure over the southwestern Gulf of Mexico
continues to produce an area of disorganized cloudiness and
thunderstorms. Environmental conditions appear only marginally
favorable for some additional development while the system moves
slowly northward during the next day or so. The low is forecast to
merge with a frontal system over the western Gulf of Mexico by
Wednesday morning. Regardless of tropical cyclone development, the
system is forecast to produce winds to gale force over portions of
the northern Gulf of Mexico by Wednesday. Additional information
on this system, including gale warnings, can be found in High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...low...20 percent.

[Sciencerocks]

Gfs and GEFS show some development of this system and to the south over Mexico there's a few surface ob's supporting a westerly wind...I think this and the energy from the other systems does have some chance of development but it is a wait and see.

[cycloneye]

AL, 93, 2023101000, , BEST, 0, 201N, 948W, 25, 1008, LO

[Sciencerocks]

[underthwx]

It only has a 20% chance of development, according to the NHC. Why is the NHC already calling this an invest?

Possibly due to its proximity to populated areas. It may also produce significant rainfall.

Yup, true that abajan...discretion being the better part of valor...makes perfect sense why it's an invest

[hipshot]

https://imagizer.imageshack.com/img923/6006/dRAHz0.gif

What's that circulation west of Mexico just south of Baha California??

[underthwx]

https://imagizer.imageshack.com/img923/6006/dRAHz0.gif

What's that circulation west of Mexico just south of Baha California??

Tropical storm Lidia?

[Nimbus]

It only has a 20% chance of development, according to the NHC. Why is the NHC already calling this an invest?

Possibly due to its proximity to populated areas. It may also produce significant rainfall.

Yup, true that abajan...discretion being the better part of valor...makes perfect sense why it's an invest

The models are showing the LLC tracking rapidly NE with tropical storm force winds and surface pressures below 1000 mb near landfall.

00z UKMET tracks further west making landfall near Mobile Bay while GFS and Euro forecast landfall between Pensacola and Apalachicola in about 48 hours.

Convection at the tail of the front near the apparent LLC this morning displaced to the NE.

[cycloneye]

8 AM:

Southwestern Gulf of Mexico (AL93):
Showers and thunderstorms have increased some, but remain
disorganized, in association with an area of low pressure over the
southwestern Gulf of Mexico. While environmental conditions appear
only marginally favorable, surface pressures have been falling near
the system, and it has a short window to develop further over
the next day or so. However, by Wednesday morning the system is
forecast to merge with a developing frontal system over the western
Gulf of Mexico. An Air Force Reserve Reconnaissance aircraft is
scheduled to investigate the system later today, if necessary.

Regardless of tropical cyclone development, the system is forecast
to produce gale-force winds over portions of the northern Gulf of
Mexico by Wednesday, and potentially heavy rainfall along the Gulf
Coast by the latter portion of this week. For more information, see
products from your local National Weather Service office, and high
seas forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...low...30 percent.

[boca]

I noticed the area moving more NE towards Florida than what is shown on the NHC map at 8am.

[ThunderForce]

It does look like it's on a bit more of a NNE/NE heading admittedly, but it's hard to tell with the LLC not being very visible. Could it be possible that the convection is being displaced by wind shear?

[wxman57]

To be clear, there is nearly a 100% chance that a low pressure area will form on the front in the NW Gulf east of Brownsville by tomorrow morning. No question about that. The weak low is already at the trailing end of a front. There will be a warm front extending east of the low center and a cold front to the southwest. Winds north of the low track will likely reach 40 mph over the offshore lease areas by noon tomorrow. Little question about that, either. Check the upper-level winds across the northern Gulf. They're blowing from the west at 75-90 mph. Such speeds would be prohibitive of this low becoming tropical, but they're no problem for a west Gulf low to form. These lows are relatively common from late fall through early spring, developing along many cold fronts during that period.

NHC is saying that there is a 30% chance that this low, that will develop, cold be classified as a subtropical or tropical storm. I think the chance of it actually being tropical are 10% or less. It would have to do so by this evening. By noon tomorrow, the low will be well south of the central LA coast, probably nearing peak intensity. By sunset, the low will be nearing the Florida panhandle and weakening.

Regardless of whether or not the NHC decides to name this low, the impacts will be identical. It will have little or no chance of significant strengthening and it will produce low-end TS winds over offshore lease blocks, along with gusty wind and rough seas. Not much impact on the northern Gulf coast west of southeast Louisiana, though. could be some heavy thunderstorms from southern Plaquemines parish tomorrow afternoon, spreading ENE along the Gulf coast tomorrow evening.

[wxman57]

I noticed the area moving more NE towards Florida than what is shown on the NHC map at 8am.

It's running into the southern edge of a very strong west to east jet stream now.

[cycloneye]

Plane is en route. Let's see if it finds some good data.

 https://twitter.com/FlynonymousWX/status/1711775952273866943