ATL: INVEST 93L - Discussion

[TomballEd]

The LLC about to leave the Florida Panhandle for Alabama is still quite obvious. Until it dies organizing a new LLC closer to the storms is unlikely. This making a run at a TD before Louisiana landfall is the ceiling for this. I absolutely understand why NHC cancelled the recon this afternoon but it would have been nice for aircraft data to be in the 0Z models.

Edit to add: Outflow boundaries (a sign of dry air) coming from the most intense offshore convection is also a negative signal for those expecting a new LLC soon.

[BobHarlem]

This thread is over if the area Southwest of PCB doesn't form before Louisiana:

[GCANE]

Radar indicating some rotation of the towers

[GCANE]

Looking better: towers refiring in just about the same location.

[GCANE]

Anti-cyclone is pretty much over the top of the convection now.
Watching if this goes ballistic around dusk.

[Frank P]

Radar indicating some rotation of the towers

Premature speculation on my part but might be the general area of the rotating HT where the lightning strikes are evident?

[GCANE]

Radar indicating some rotation of the towers

Premature speculation on my part but might be the general area of the rotating HT where the lightning strikes are evident?
https://i.ibb.co/Y4kmgZL2/IMG-5360.jpg

Spot on

[Nuno]

Doesn't look like much will happen today with it, maybe as it gets closer to Louisiana. All the models keeping it in the general area and looping it back into the gulf in a week or so are wild though. And that keys thing is still there.

https://i.postimg.cc/gcvqQb2N/83073179.gif

There was some vicious lightning this AM in South Florida from that keys thing.

[GCANE]

This may be pushed to the southwest and IMHO there is a chance it could miss the MS Delta.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Wed Jul 16 2025

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

Northeastern and north-central Gulf (AL93):
Surface and radar observations indicate that a westward-moving
broad area of low pressure is located along the coast of the
Florida Panhandle near Panama City. The associated shower and
thunderstorm activity remains disorganized and located mainly south
and southwest of the center. This system is forecast to continue
moving westward across the northern portion of the Gulf through
tonight, reaching the coast of Louisiana by Thursday. If this system
moves far enough offshore, environmental conditions over the Gulf
appear generally favorable for additional development, and a
tropical depression could form over the next day or two before
the system moves fully inland by the end of the week.

Regardless of development, heavy rainfall could produce localized
flash flooding over portions of Florida through through today.
Heavy rainfall could also cause flash flooding for portions of the
north-central Gulf Coast beginning late today and continuing through
Friday. For additional information, please refer to products issued
by the Weather Prediction Center and your local National Weather
Service office.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...medium...40 percent.

$$
Forecaster Beven

[wxman57]

LLC over Florida is definitely weakening, but I see no sign of something spinning up offshore. Convection near the LA Delta is weakening, as is evident by the outflow boundaries. Small blob south of Pensacola isn't doing much, but that would be the place to watch for center redevelopment. However, it's only about 175 miles from reaching SE LA, so there is not much time left. I think it's unlikely to become a depression before tomorrow morning when it moves inland. Good news is that GFS develops another similar situation next Monday! Yeah, right...

[TomballEd]

I think there is enough of the LLC left just inland that one small blob of convection won't be able to generate a new LLC anytime soon and as mentioned, time is running out. Even a new LLC forming under the tiny blob isn't missing Louisiana.

[USTropics]

I think there is enough of the LLC left just inland that one small blob of convection won't be able to generate a new LLC anytime soon and as mentioned, time is running out. Even a new LLC forming under the tiny blob isn't missing Louisiana.

I'd agree, it's the current LLC over land or nothing with this system. Here is the 12z ECMWF going back two days ago. This is a cool product where areas shaded in green indicate cyclonic vorticity at 850mb, while purple areas are typically associated with fronts. We can see the ECMWF tracks the LLC the entire time up to the coast of LA tomorrow morning around ~8AM ET:


Looking at the 12z HAFS-B, around midnight ET would be the earliest we would see the LLC remerge over the GOM:


imo this will be another scenario where invest 93L will be the most organized right at landfall tomorrow morning. Enough to be classified as a tropical cyclone? I would say no, but the end result doesn't really matter (mild gusts and rain being the main impact).

[TallyTracker]

The rain has been training over Tallahassee all day on the east side of the LLC. We’ve gotten a few inches of rain with some gusty winds in squalls. I think that will be the main thing with this system. Fortunately it was hot and dry before this so flooding should be minor in the Panhandle.

I’d put development odds at 10-20% at this point though the NHC may wait to lower it to keep the focus on the flood threat. The LLC has been persistent and does not seem to be dissipating. As others have noted, unless it redevelops under the new blob off PCB, it’s not developing.

[jaguars_22]

Anyone notice the twisting in the blob below New Orleans?

[LadyBug72]

Anyone notice the twisting in the blob below New Orleans?

Can you please share radar?

[BobHarlem]

Anyone notice the twisting in the blob below New Orleans?

Can you please share radar?

Afternoon storms are pumping up with the bands well away from where 93L is. The area south of New Orleans is just part of that front convective area. It's starting to look pretty unlikely that 93L develops.

[jaguars_22]

......its dead Jim...

The HRRR model has been showing this deepening heading more towards Texas... according to the satellite view

[MGC]

Poof.......MGC

[Stratton23]

No development this time, to close to land, however 93L may get a 2nd shot at developing down the road in the gulf again, storybook isnt closed on this one yet even if it loses the “ invest “ name