Hurricane Isaias is knocking on the door of major hurricane strength. Meanwhile, the Gulf Coast is almost out of time to get ready. The National Hurricane Center’s latest advisory puts the storm at 110 mph, one mile per hour short of Category 3. Landfall is expected tonight or early Saturday. On top of that, the Hurricane Isaias storm surge forecast just got worse.
The 7 a.m. CDT advisory also came with a correction, and it matters. Forecasters revised the surge values and areas. The peak number is now higher than what many local outlets reported on Thursday. For the earlier picture, see our Cat 2 update on the Gulf Coast threat.
Hurricane Isaias Is a Mile Per Hour From Major Status
As of 7 a.m. CDT, the center sat about 245 miles south of Pensacola. It was also 170 miles south-southeast of the mouth of the Mississippi River. At that point, the storm was moving north-northeast at 15 mph. Minimum central pressure was 958 millibars, as measured by a dropsonde from a hurricane hunter aircraft.
Category 3 starts at 111 mph, so technically Isaias is still a Category 2. Fox Weather noted the same thing. Even so, the hurricane center said the storm will likely become a major hurricane this morning. In fact, it should stay dangerous through landfall.
Still, don’t get hung up on the label. Hurricane-force winds reach 30 miles from the center, and tropical-storm-force winds stretch 185 miles. That is a wide shield of trouble. Even so, its biggest threat is the Gulf Coast storm surge it pushes ahead of it.
The Isaias Surge Forecast Is the Real Headline
Wind gets the attention, but water does the damage. The corrected advisory says the Hurricane Isaias storm surge could reach these heights above ground if the peak arrives at high tide:
- Alabama/Florida border to Grayton Beach, FL: 6 to 9 feet
- Grayton Beach to Indian Pass, FL: 4 to 7 feet
- Dauphin Island to the Alabama/Florida border: 4 to 6 feet
- Indian Pass to the Steinhatchee River, FL: 4 to 6 feet
- Mobile Bay, and the Mississippi River mouth to Dauphin Island: 3 to 5 feet
Earlier local forecasts had the Panhandle coast at 5 to 7 feet, so the top end moved up. In addition, a Storm Surge Warning covers the coast from the mouth of the Mississippi River to the Suwannee River. The hurricane center calls it a life-threatening situation. It tells people to follow local evacuation orders.
Who Faces Warnings, Evacuations and Hurricane Surge Flooding
A Hurricane Warning runs from Ocean Springs, Mississippi, to the Bay/Gulf County line in Florida. Tropical Storm Warnings flank both sides. Nothing changed in the warning areas with this advisory. Hurricane surge flooding remains the main reason officials want people out.
On the ground, the response is already underway. Okaloosa County ordered its coastal Zones A and B to leave. Escambia and Walton counties issued mandatory orders as well. CNN reports that Alabama Gov. Kay Ivey told non-residents to clear out of south Baldwin County and Dauphin Island. Meanwhile, Chevron and Shell are shutting in some offshore production and pulling workers, and some Florida airports have closed.
Evacuation details are changing by the hour. Check with your county emergency management office, not a screenshot someone posted last night. Our Friday morning brief tracks the latest.
Rain and Tornadoes Reach Far Past the Coast
Here’s the thing: if you live a few hours inland, this storm is still your problem. The hurricane center expects 4 to 8 inches of rain across southern Alabama, the Florida Panhandle and Big Bend, and southwest Georgia. Local totals could reach 15 inches. Much of the rest of the Southeast should see 2 to 5 inches. The Southern Appalachians and coastal Carolinas could see up to 10.
As a result, flash flooding is likely, and river flooding could be significant. Even far from the water, the Hurricane Isaias storm surge pushing up rivers and bays can worsen that flooding. Tornado risk begins late this afternoon along coastal Alabama, the Panhandle and far southwest Georgia. It then continues Saturday through Georgia and the Carolinas.
What to Watch Next on the Gulf Coast Storm Surge
The next complete advisory lands at 10 a.m. CDT, and it should settle the Category 3 question. The bigger uncertainty is exactly where the eyewall crosses the coast. Surge can swing wildly over short distances, so the Isaias surge forecast could shift again. We first flagged this uncertainty when Invest 92L was still a question mark.
The hurricane center’s message for the warning areas was blunt: finish preparations within the next few hours. The Category 3 label will be settled by lunchtime. The water will not wait for it.
