Tropical Development Possible in the Southern Gulf Next Week

August 24, 2023

Synopsis, there is a 50% chance of development in the Caribbean or southern Gulf early next week. Lots of forecast uncertainty exists, but a track to the north or northeast looks likely if a storm does develop.

The National Hurricane Center is watching an area in the Western Caribbean for tropical development. Models have been hinting at development here for over a week and just yesterday became more bullish. In the late spring and towards fall we sometimes see what is called a Central American Gyre (CAG) setup which can sometimes spit out an area of rotation that becomes a seed for tropical development. I'm not sure if that is the case here (it sort of doesn't matter), but the NHC is forecasting a 10% chance of development through 48 hours and a 50% chance through 7 days in the area where we see a CAG. This area showed up on the 7 Day Outlook yesterday evening and went from a 20% chance of developing to 50% in 12 hours. Based on that and what the models are showing, it is something we need to watch.

Development could happen as early as Sunday or Monday in the Western Caribbean or later into Tuesday in the southern Gulf with a potential storm probably tracking to the north or northeast. For the rest of this discussion take it with a grain of salt. The track and strength of a tropical cyclone is difficult to forecast before the system forms. Once a low level center forms and that data is being fed into the models they start producing much better solutions. Before that time the models are more or less guessing where and when the center will form (if it does) and that can make a big difference for the forecast beyond that. With that said, a track to the north-northeast across the Gulf with a landfall somewhere along the Florida Gulf coast looks to be the most likely solution. The solutions are sort of centered on the Big Bend area, but really anywhere from the Florida/Alabama line to Fort Myers is in play (maybe beyond that to the west and the east). Storm strength is fairly uncertain also. Right now I'm not seeing many solutions that are producing a really strong storm but that doesn't mean it isn't possible. The Gulf is plenty warm enough so given enough time and the right environmental conditions a strong storm is possible. That being said wind shear and some dry air may be a bit of an issue but models differ on this so it's hard to know what environment a potential storm may see. What is interesting is that between the ECMWF (Euro) and GFS (US) operational models the ECMWF is much more bullish on development while also forecasting what looks like a more harsh environment. For whatever reason the GFS isn't showing any development at all (as of this morning) even though the environment it forecasts is better. Both the ECMWF and GFS ensembles have similar solutions as the operational models with maybe the main difference being that the mean solution for the Euro ensembles shows a better environment than the operational Euro by itself. This is notable because within the model suites of each the operational model isn't producing an outlier solution which tends to increase confidence in that solution (other model solutions notwithstanding). It is also interesting that the GFS is so quiet on this, especially because it often has a bias where it develops storms where there shouldn't be one. For what it's worth the Canadian model (which can be too aggressive at times) has a similar solution as the ECMWF. We'll see if the Euro backs off on this in future runs or if the GFS picks up on it and starts showing stronger chances for development.

That's probably more info than you need at this point but I wanted to point out the forecast uncertainty and what I'm seeing. I do think it is more likely than not that we'll see a storm develop in the Gulf next week. That being said if nothing came of this it wouldn't be the first time this year when expected development didn't occur. I think we'll have a better picture of what the possibilities are this weekend.

Looking at the rest of the Atlantic there are no other concerns right now although the high level of overall activity is continuing. Franklin doesn't look to be a threat to the East Coast, but it may try to sneak in close to the Northeast US around midweek.

That's it for today. If you've been slacking (like me) on your hurricane kit this would be a good time to get some supplies.

Chris