[brakos82]

Tropical Storm Isaac battering the Florida Keys, Gulf Coast landfall uncertain.... 65mph/995mb/wnw-18

Isaac's inner rain bands are landing on the Keys this afternoon, bringing heavy rain and winds upwards of 50mph to the islands. Conditions will remain poor throughout the day and overnight tonight.

Isaac is expected to gain hurricane strength over the warm Florida waters, then move into the Gulf. From here, the forecast models split into two distinctive paths.
The first (and original) takes Isaac north into the Florida panhandle, likely as a cat-1 or weak cat-2 hurricane. There is an eddy of cooler water off Florida's west coast, which would keep Isaac from intensifying too much.
The second option takes Isaac on a more northwesterly track, with landfall in Louisiana as a cat-2 (possibly cat-3) hurricane.

Isaac is a very large storm, with tropical-storm force winds extending 205 miles from the center. In comparison, Katrina's TS-force winds at landfall extended 235 miles, and Ike's 275 miles. Wind speed changes of 5-10 mph will be significant in forecasting storm surge totals. Even if Isaac makes landfall as a minimal hurricane, storm surges will be high because of the storm's size.