More Evidence for a Westward Push
Last night, I wrote up a post about how amazingly consistent the GFS ensembles were in putting Isaac inland over Louisiana; that trend continues this morning, and now the ECMWF (European) is on the right track too. Here’s the 6Z GFS 500 mb ensemble:
And this is the 0Z ECMWF. It is not quite as certain about the situation as the GFS (there are more red circles representing Isaac scattered away from that thicker white one):
This kind of consistency really settles it in my mind that this is a much more serious situation for the Louisiana and Mississippi Gulf Coasts than for the Alabama or Florida Coast. That’s not to say there will be NO impact at all! Storm surge of 3 to 6′ is still possible in Mobile and Baldwin Counties (NOAA SLOSH Model)`:
The next big question to answer is what kind of impact this storm could have on the Tennessee Valley. In short, our over-all risk of very heavy rain and tornadoes is low, but it is not zero. The Hydrometeorological Prediction Center has painted a large swath of heavy rain across the South due to Isaac’s uncertainty:
Our best chance of rain will be in the Thursday-Friday time frame around here. The best chance of heavier, tropical downpours will be a little to the south and west of the Tennessee Valley, but we could still get some beneficial rain for some of us this week.