CORRECTION : Sunday Night Update for TS Sally

You all know what day it is, the subject of my previous email said Monday, I'm getting ahead of myself. Sorry about that.

September 13, 2020

Sally is starting to organize a lot more tonight and I think we're seeing the beginning of the intensification phase that's been expected. With the 10 p.m. update, the NHC has shifted Sally's track back to the east a little and slowed the storm down. While the track center hasn't moved a whole lot, the cone has come quite a bit to the east due to the change in the turn location. The NHC has the storm making landfall right after daybreak Tuesday raking the Mississippi Delta as a 90 mph storm. In their discussion the NHC states that their forecast is to the west of most of the guidance so it may be adjusted to the east even more overnight. Earlier today I was feeling pretty confident that the Florida Panhandle was looking pretty safe but I'm not as confident tonight. I'm not trying to get anyone too excited, I just want to keep you informed about the different possibilities. Most of you are in the Panama City area and I think you all are fine for now, but people a bit more to the west need to stay alert.

Both of these trends, to the east and slowing down, are concerning because it gives the storm more time over water if it misses the Delta to the east which would allow for more intensification and increases the track uncertainty if it stalls over water. If we're getting back to the scenario where it could stall over water that allows more time for the steering environment to change which could ultimately bring a stronger storm more to the east. Also concerning is the 18Z HWRF run, after showing the storm being barely a hurricane for the 6Z and 12Z runs, it is back showing nearly a category 3 storm making landfall in Mississippi. Other intensity models continue to support a category 2 storm but about half show category 1 intensity. Something people in the extreme western Florida Panhandle need to watch for is if the storm stalls just off the Mississippi Delta tomorrow night it might start curving to the east as it heads north again Tuesday night into Wednesday, putting the Pensacola area or even points a little east at greater risk. I think this is an outlier scenario at this point, but it is a possibility. This area is back in the cone now and the cone only covers two-thirds of historical forecast errors. We'll see what the overnight trend is and if the NHC brings the track more to the east.

I also want to mention that the SPC is now indicating a marginal chance for severe weather tomorrow, coinciding with a 2% tornado risk, from just west of the Florida Big Bend through southeast Louisiana. People right along the coast should stay aware of the weather as rain bands come ashore.

Let's see what tomorrow brings. 

Have a good evening.

Chris