September 14, 2020
The 10 p.m. advisory for Hurricane Sally was just issued by the NHC. Sally thankfully hasn't strengthened since earlier and has probably weakened a little. The forecast has shifted east again, now showing a landfall Wednesday morning just west of Mobile Bay as a 110 mph storm. Sally is crawling along now at about 3 mph and is expected to gradually turn more to the north and then to the northeast. The eastern edge of the cone is now all the way over towards Fort Walton Beach, although the hurricane warning area has not been extended in that direction. It also still goes nearly as far west as the LA/MS border...
Here's the NHC's words regarding the track:
"Weak high pressure ridging to the north and east of Sally is expected to cause the hurricane to continue to move slowly west-northwestward to northwestward for another 12 hours, bringing the center of the storm very near the northern Gulf coast. By Tuesday afternoon, when the hurricane will likely be just offshore, the models show the steering currents collapsing and Sally is likely to drift northward before finally turning northeastward ahead of a developing mid-level trough over the central U.S. by late Wednesday. There continues to be a significant amount of uncertainty on exactly where and when Sally turns northward and makes landfall, with model solutions ranging from a landfall on the Florida panhandle to a landfall in extreme southeastern Louisiana. It should be emphasized that it is always challenging to forecast the track of hurricanes in weak steering currents, and in Sally's case the weak steering is occurring very near land."
There's some meteorologist talk in there, but I think you can see just how much uncertainty we're still dealing with.
Sally still hasn't completely closed off an eye, and that has kept it from intensifying more. If it is able to close off all the way around we should see it strengthen some more. Hurricanes generally strengthen more after dark, so we could see that happen overnight. It may be trying to do so as I'm writing this based on what satellite and radar are showing. A run at category 3 strength is still possible, but I don't think we'll see too much more than that based on the intensity guidance. Another thing to note about the intensity is that if Sally sits in one place long enough, maybe longer than 24 hours, it will actually start to cool the water to where it can't intensify any more, it pulls out all the usable heat. Wind shear will also be increasing over the next day so that will help provide a more unfavorable environment as well.
I think if we do see a track towards the far eastern side of the cone, it's likely to be one that is very slow at first and probably right along the coast after having used up a lot of the heat. There's also not as much heat available in the shallow coastal waters and that combined with some land interaction could weaken the storm on an extreme eastern track. So even though places as far east as Destin are starting to look like they're at risk, I don't think we'll see the storm make a beeline for that part of the coast over open water while maintaining or increasing strength. It's not impossible but I don't think it is likely. For places between Gulf Shore and West Pensacola I think the risk of this is a lot higher. Regardless of my thoughts things have been changing every so many hours so don't let your guard down if you're near Sally's path.
Along with wind, storm surge and flooding rainfall are going to be major issues for some areas, so please make preparations for these hazards.
To add to this the risk for tornadoes tomorrow has increased a little, with the SPC now showing a 5% risk area along the coast in the yellow area below. Keep an eye out for the rain bands as they come ashore and have a way to receive alerts.
I'll be keeping an eye on things overnight, the next full advisory is at 4 a.m. I may send out an update then or wait until the 10 a.m. advisory.
Have a good evening.
Chris
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