Labor Day Tropical Weather Update

September 2, 2024

Happy Labor Day. I know for me the three day weekend is most welcome.

TL;DR we need to keep watching the Caribbean system as it moves west. Development chances are currently on the low side (40%), but expected to improve. Lots of uncertainty still, but any tropical system in the western Caribbean in September needs to be watched closely regardless. Too many details below, I guess I felt like writing a lot today.

I've been waiting for this area in the Atlantic to get figured out before sending another update but as of this morning I don't think we're any closer to knowing what is going to happen. You can see there are three areas being watched, but the only one of any real concern is the orange X in the eastern Caribbean, that is the same system we were looking at a week ago. The area in the Gulf is bringing a lot of rain to parts of Texas and Louisiana but is not expected to develop, current chances are at 10%. Another tropical wave just coming off the African coast has a 40% chance to develop over 7 days. It is something to watch but it doesn't look to make it very far to the west based on current modeling.

Back to the Caribbean system, the NHC gives this area a 40% chance of development through 7 days. In my previous update I said that I didn't expect it to do much and regardless of what ultimately happens that statement was premature. Computer models can't seem to figure this thing out. A few days ago I was a bit worried about this one. For a few days development looked very likely, with some scary scenarios in some of the solutions, only to see that wax and wane every other model run, now tapering off a bit overall. As of this morning development chances look to be lowering in the short term but we still need to keep watching. Thankfully this system has remained broad and elongated without any consolidating areas of vorticity (spin) and hopefully this continues as this moves off to the west. It looks like some moderate wind shear and stronger winds on the north side of the wave axis may be currently inhibiting development but the NHC expects conditions to improve in a few days in the western Caribbean. If you know your history you know that a moderately healthy tropical wave in the western Caribbean in September can be bad news, so we need to keep watching.

As mentioned, models can't figure this thing out. The operational GFS is currently the most bullish on development but the others not so much. The ensembles are indicating a medium-low chance of development, so I think the NHC's assessment of 40% is right on. Either way, the off again and on again signals from run to run are enough to pay attention to. Were this to develop, the potential tracks are somewhat troubling. Earlier on (last week) there were some model tracks that took any developing system out in the Atlantic as well as into the Gulf. Now that it has made it farther west without development the solutions all end up in the Gulf with possibilities from Mexico to Florida. Southern solutions (Mexico) seem to be the most likely at this point, but I think confidence in where any system that does development may go is on the low side at this point, there are just too many unknowns. Timing is another unknown. We could see development as soon as the end of the week (unlikely) to late the following week if this gets penned up in the southern Gulf by a front (low confidence). The most likely scenario is slow development around the weekend near the Yucatan or southern Gulf, at which point we'll need to watch a little closer to see where it goes from there. There are also too many unknowns to speculate on intensity, but all possibilities are on the table.

A few more notes. Cooler(ish) and wet weather is on the way towards the end of the week, with a warm up near the middle of the month near the coast. We'll see one or two fronts push through during this period, perhaps with one or both stalling near the coast or offshore. I will welcome the rain and cooler temps, but we'll need to watch the Gulf after these push offshore in case something tries to develop along the tail end. There is some low confidence model support for this idea.

That's it for today. If you've made it this far, thanks for reading!

Have a great Labor Day.

Chris