Invest 97L--50% Development Odds

[WxWatcher007]

We have homebrew potential in the Gulf as an area of low pressure has formed in the northern part of the region and is producing persistent disorganized convection. 

The NHC has taken note, and the odds of development have gradually risen to 30%. 

The key inhibitor here is time, although the guidance has pointed to a more modest development signal, this is likely to be onshore near the Texas/LA border in 48-72 hours. Generally speaking, however, the conditions do seem to be favorable with very warm SSTs (not thinking about OHC needed to sustain a strong system given proximity to land and timing) in the northern Gulf. 

There is dry air to its north, and that could also be an inhibiting factor, but so far that hasn't prevented consistent convection, which has been deep at times. The more consistent deep convection can be, the more likely we see eventual pressure falls and the tightening of the low pressure. However, should dry air make an intrusion it could disrupt any progress toward organization into a TC. 

Importantly, shear is low in the basin. In fact, it's basically the only place in the Atlantic that has a large enough area of low shear to have a meaningfully large enough window for development. That's consistent with my peak season forecast, but we'll see if it leads to another short lived TC here.

Shear may be kept at bay, but the signal is a bit mixed on whether we see some southerly shear eventually develop. Overall, I think this is a legitimate homebrew opportunity for a weak tropical storm that would impact the northern Gulf coast in a couple of days. I think there's a good chance 97L has slightly increased odds and is an orange for the 2pm outlook. 

Northern Gulf of America (AL97):
Showers and thunderstorms associated with an area of low pressure 
located about 125 miles south of the coast of southeastern Louisiana 
have become more concentrated. However, current surface observations 
indicate that the system has not yet strengthened. Slow development 
of this system is possible during the next couple of days as it 
drifts westward to west-northwestward across the northern Gulf. 
Interests along the Louisiana and Upper Texas coasts should monitor 
the progress of this system.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 7 days...low...30 percent.

$$
Forecaster Beven

 

[GaWx]

12Z UKMET doesn’t quite designate this as a TD but it does have 25 knot winds just offshore LA Mon night and landfall Tue AM near TX/LA border. Lowest SLP only gets down to 1011 mb fwiw.

[GaWx]

12z Euro: looks like a TD that comes ashore near LA/TX border midday Tue.

[WxWatcher007]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Aug 30 2026

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

Northern Gulf of America (AL97):
A low pressure area is located over the northern Gulf of America 
about 125 mils south of the coast of southeastern Louisiana.  
Satellite imagery and recent satellite wind data indicate that this 
system has become better organized since yesterday.  Additional 
development is possible as the low moves slowly west-northwestward, 
and a short-lived tropical depression or tropical storm could form 
before the system reaches the Upper Texas or southwestern Louisiana 
coasts Tuesday or Tuesday night. Interests along the Louisiana and 
Upper Texas coasts should monitor the progress of this system. 
Regardless of development, locally heavy rainfall is possible over 
portions of the Upper Texas or southwestern Louisiana coasts during 
the next couple of days.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 7 days...low...50 percent.

 

[WxWatcher007]

This one has legs 

[NorthArlington101]

This one has legs 

Twitter folks like it a lot. Pretty surprised that this doesn’t have a PTC designation. Not sure what else it would be for other than to use it for a potential storm developing that will be surely impacting land which needs a sexier name than “97L” to grab media attention.

[Scott747]

1 hour ago, WxWatcher007 said:

This one has legs 

Slow season is getting to you I see....

[Scott747]

13 minutes ago, NorthArlington101 said:

Twitter folks like it a lot. Pretty surprised that this doesn’t have a PTC designation. Not sure what else it would be for other than to use it for a potential storm developing that will be surely impacting land which needs a sexier name than “97L” to grab media attention.

NHC is still old school and likes the 10 pm news cycle on a Sunday night so I'd be surprised if they didn't designate a PTC or even straight to depression at 10.

Weekday and this might have been a PTC at 5, although it still seemed a little early this afternoon with the lack of storms around the center.

 

[NavarreDon]

I’ve learned to trust the crew at the NHC about jumping the gun. That said I’m not calling for it, but all the visuals & ascat passes say that they could issue a special for PTC. Nice diurnal blow up starting now.


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[Scott747]

19 minutes ago, NavarreDon said:

I’ve learned to trust the crew at the NHC about jumping the gun. That said I’m not calling for it, but all the visuals & ascat passes say that they could issue a special for PTC. Nice diurnal blow up starting now.


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Doubt they would do a special for a PTC. Could get a hint that one is coming with the update at 7 and going red.

[NavarreDon]

Doubt they would do a special for a PTC. Could get a hint that one is coming with the update at 7 and going red.

That makes sense, what are the possibilities of going straight to TD at 10?


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