The National Hurricane Center (NHC) has updated its storm surge flooding forecast for parts of northwest Florida, now predicting up to 9 feet of water above ground level from the Alabama-Florida border to Grayton Beach. This adjustment was issued in the revised bulletin 11A at 7:00 a.m. CDT on Friday, October 9.
The NHC's official bulletin indicates that this sector could experience flooding between 6 and 9 feet (1.8 to 2.7 meters) if the peak surge coincides with high tide. This measurement refers to water height over normally dry ground, not wave height. The updated report specifically highlights changes in predicted heights and affected areas.
The new forecast exceeds the previous maximum of 7 feet (approximately 2.1 meters) noted in bulletin 11, as reported earlier by CiberCuba. The NHC has now provided a more detailed outline of the coastal sections, with the highest value set between the Alabama-Florida border and Grayton Beach. The correction does not alter the existing weather advisories and alerts.
Coastal Areas Facing Severe Flooding Risks
Between Dauphin Island, Alabama, and the Florida border, the NHC anticipates flooding of 4 to 6 feet (1.2 to 1.8 meters). From Grayton Beach to Indian Pass, Florida, the estimate is 4 to 7 feet (1.2 to 2.1 meters); from Indian Pass to the Steinhatchee River, 4 to 6 feet (1.2 to 1.8 meters) is expected.
For the stretch between the Steinhatchee and Suwannee Rivers, predictions are for 3 to 5 feet (0.9 to 1.5 meters), and from Suwannee to Yankeetown, 2 to 4 feet (0.6 to 1.2 meters). The forecast from the mouth of the Mississippi River to Dauphin Island, including Mobile Bay, is 3 to 5 feet (0.9 to 1.5 meters).
The agency warns that the most severe flooding could occur in coastal areas where the wind drives water inland, accompanied by large and dangerous waves. The severity of flooding depends on the timing of the surge with tidal cycles, which can vary significantly between nearby localities.
Isaias Approaches with 175 km/h Winds
At 7:00 a.m. CDT (8:00 a.m. in Miami), the center of Isaias was located near 27 degrees north latitude and 87.7 degrees west longitude, about 390 kilometers south of Pensacola, Florida. It was moving north-northeast at 24 km/h, with maximum sustained winds of 175 km/h and a minimum central pressure of 958 millibars, according to NHC and U.S. Air Force Reserve reconnaissance observations.
At that time, Isaias was at the upper limit of category 2. The NHC anticipated it could reach category 3 by Friday morning and remain a dangerous hurricane as it makes landfall on the northern Gulf Coast, likely overnight Friday into early Saturday, October 10.
Hurricane-force winds extended up to 45 kilometers from the center, while tropical-storm-force winds stretched as far as 295 kilometers. The NHC expected Isaias to turn north during the day on Friday and approach the U.S. Gulf Coast later that afternoon.
Warnings and Alerts in Place
A storm surge warning remains in effect from the mouth of the Mississippi River to the Suwannee River and a hurricane warning from Ocean Springs, Mississippi, to the boundary between Bay and Gulf counties in Florida. Tropical storm warnings are also in place from the boundary between Jefferson and Plaquemines parishes in Louisiana to the west of Ocean Springs, and from the east of the boundary between Bay and Gulf counties to the Aucilla River in Florida. A storm surge watch is also in effect between the Suwannee River and Yankeetown.
Rainfall between 100 and 200 millimeters is expected over the weekend in southern Alabama, northwest Florida, the Big Bend region, and southwest Georgia, with isolated totals potentially reaching 380 millimeters, particularly in areas affected by persistent rain bands in the Florida Panhandle and Big Bend.
In other southeastern U.S. areas, accumulations between 50 and 125 millimeters are anticipated, with local maxima nearing 250 millimeters, notably in the southern Appalachians and coastal areas of the Carolinas.
These rains could lead to flash flooding and urban flooding, with significant impacts in southern Alabama, northwest Florida, and southwest Georgia. River flooding is also expected, some of which could be substantial.
The NHC warns of a tornado risk from late Friday afternoon into the night along the coast of Alabama, northwest Florida, and southwest Georgia. The threat will persist Saturday in parts of eastern Alabama, Florida's Panhandle, Georgia, and the Carolinas.
Additionally, swells generated by Isaias, already affecting western and northern sections of the Yucatan Peninsula, will extend to the northern Gulf of Mexico. These conditions could cause dangerous surf and potentially deadly rip currents.
The NHC urges completion of preparations in hurricane and storm surge warning areas and advises following local evacuation orders. Flood threat maps can be viewed on the NHC's official storm surge forecasting page.
FAQs on Hurricane Isaias Impact
What is the maximum expected flooding from Hurricane Isaias in Florida?
The National Hurricane Center predicts up to 9 feet of storm surge flooding in parts of northwest Florida, particularly from the Alabama-Florida border to Grayton Beach.
What areas are under hurricane warnings due to Isaias?
Hurricane warnings are in effect from Ocean Springs, Mississippi, to the boundary between Bay and Gulf counties in Florida.
What rainfall totals are expected from Isaias?
Rainfall between 100 and 200 millimeters is expected in southern Alabama, northwest Florida, and southwest Georgia, with isolated totals reaching 380 millimeters in certain areas.