Tropical storm Isaac appears slightly better organized this morning and is on the cusp of becoming a hurricane. Signs of intensification are clear and present: its pressure has slowly been dropping and the storm center has repositioned itself closer to the strongest thunderstorms.
Although forecasting Isaac’s intensity has proved tricky, it is likely to become a hurricane today, with further strengthening tomorrow as it nears landfall to perhaps category 2 strength (maximum winds to 100 mph or so).
Track forecasts for Isaac’s landfall, ominously, have converged around New Orleans - although the “cone” of possible landstrike locations spans from the panhandle of Florida to central Louisiana. Everyone in this region should be prepared for hurricane conditions.
This entire region is vulnerable to storm surge - the wall of water that the storm pushes ashore - that could reach 6 to 9 feet above ground level in worst case scenarios. The worst storm surge is likely to occur just east of the storm center, where the direction of the storm’s circulation (counter clockwise) coincides with its forward motion towards the west and northwest. This same region - difficult to pin down at this point - will also be buffeted by the strongest and likely destructive hurricane force winds.
But rainfall and inland flooding may well end up as the storm’s biggest impact, as Isaac’s forward speed slows down as it moves inland. Widespread 8-12 inch rainfall totals are likely, with some locations receiving more than 20” perhaps.
At 8 a.m., Isaac was 185 miles west southwest of Ft. Myers, Florida and was moving west northwest at 14 mph. Maxium sustained winds are 65 mph and its central pressure is 29.18” or 988 mb (down from 993 mb at 11 p.m. last night).
Link: Interactive tracking map
Tropical storm warnings cover much of Florida’s west coast and hurricane warnings stretch from the western section of the Florida panhandle to the central coast of southern Louisiana, including New Orleans. See above map.
For the latest watches and warnings, please follow the National Hurricane Center’s website.
We will have another Isaac update this afternoon.