Isaias Named, Concern Grows Around Significant Impacts From Wind, Water, Tornadoes

The National Hurricane Center named Tropical Storm Isaias overnight, with the storm expected to further intensify to major category 3+ hurricane status over the next 48 hours. Isaias is forecast to make landfall along the Gulf Coast between Louisiana and the Florida Panhandle late Friday night into Saturday morning. Significant impacts from heavy rain, high winds, and isolated tornadoes are expected as the storm moves inland and travels north into the Ohio Valley while decaying through Sunday.

Here is the latest forecast track + probability of tropical storm force winds from NHC early Wednesday morning:

While wind + water impacts are expected to be significant and widespread, I continue to wonder if Isaias won't be a prolific tornado producer along the Gulf Coast on Saturday morning, northward into the Ohio Valley by Sunday.

Isaias will be picked up by an incoming upper-level wave in the sub-tropical jet on Thursday and Friday, steering the storm north and east toward the Gulf Coast. By the time the storm makes landfall early Saturday morning, the interaction with this incoming jet stream wave should be to increase shear disorganizing the storm some from it's more classic tropical form into somewhat of a hybrid low that could foster several corridors of tornadic supercells.

There is still quite a bit of forecast uncertainty regarding the exact track of Isaias, and when/where this risk for rotating storms could peak. The most favorable zone for rotating storms and tornadoes should be near and east of the track of the storm, which for now seems to favor southern Mississippi and Alabama into the Florida Panhandle, with this zone lifting north into the rest of MS, AL and perhaps into TN, KY and portions of the Ohio Valley by Sunday.

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