Hurricane Isaias is headed for a Gulf Coast landfall Friday night after strengthening in the Gulf, and the storm is already carrying 85 mph sustained winds as it sits just under 400 miles south-southwest of New Orleans. Moving east-northeast at 10 mph, Isaias is expected to bring storm surge, rainfall flooding and high winds to a broad stretch of the coast.
The warning map is already wide. A storm surge warning runs from the Mouth of the Mississippi River to the Suwannee River, Florida, while a surge watch reaches south to Yankeetown, Florida. Hurricane warnings extend from Ocean Springs, Mississippi, to the Bay/Gulf County line in Florida, with additional hurricane warning coverage inland in parts of southwest Alabama and the western Florida Panhandle. Tropical storm warnings also stretch from the Jefferson/Plaquemines Parish line south of New Orleans to west of Ocean Springs, then east of the Bay/Gulf County line to the Aucilla River, Florida, and into much of inland southern Alabama, parts of southeast Mississippi, the rest of the Florida Panhandle not in hurricane alerts and extreme southwestern Georgia.
That means the storm is not just a coastal problem. Preparations to protect life and property from damaging winds and storm surge should be finished by tonight, before conditions deteriorate farther as the system moves north. The same forecast that is driving the alerts also shows why the public is being told to move quickly: Isaias has already doubled its sustained winds from 40 mph at 5 a.m. on Wednesday to 80 mph at 5 a.m. on Thursday, and it is expected to strengthen to at least a Category 2 hurricane by Thursday night in the central Gulf.
There is still a catch in the forecast. Warm Gulf water and a moist air mass are feeding the storm now, but increasing wind shear as it moves north Friday near the Gulf Coast is expected to work against it. Wind shear is hostile to tropical systems, and forecasters say Isaias is likely to lose some wind intensity closer to landfall. Even so, the threat does not disappear if the top wind speed eases; surge, flooding rain and damaging winds can still reach well inland.
By Friday night, the key question will not be whether Isaias is still organizing, but how much of its strength survives the trip north. For people under warnings, the deadline is already set: tonight is the time to finish preparations, because the next major milestone is landfall itself.
