Not unexpectedly, Isaac seems to be surviving its trek across Haiti with it's circulation intact. In moved just far enough west for its core to miss the highest mountains, although the Hispaniola and Cuban land masses will have some tempering effect for the next day or so. The upshot is... the Florida Keys need to get ready for hurricane conditions immediately, including 1 to 3 feet of storm surge flooding at high tides. The worst of this flooding will not occur until Monday when the storm has past and the backside winds push the water into Florida Bay.
For Miami and the entire metro area, be ready for an extended period of very bad weather with winds gusting to hurricane force... likely through Monday. Some flooding around Biscayne Bay is expected at high tide.
The bad weather has already begun in South Florida due to an upper-level feature that is helping pull Isaac north. Well more that a FOOT OF RAIN may fall between today's rain and that directly related to Isaac.
Be prepared to stay indoors in a safe building through Monday. When the wind starts blowing in earnest, stay away from windows.
More on farther up the west coast later.
See you on The Weather Channel.