Hurricane Isaias reached 100 mph sustained winds on Thursday afternoon, Oct. 8, when Hurricane Hunter aircraft flew into the storm over the central Gulf, and by 10 p.m. CDT the National Hurricane Center had raised that to 105 mph with the minimum central pressure down to 969 millibars. The hurricane warning for the northern Gulf Coast has held steady across both advisories, covering the shoreline from Ocean Springs, Mississippi, east to the Bay/Gulf County line in the Florida Panhandle. Landfall is forecast within that area late Friday or early Saturday.
Hurricane Hunter winds: 100 mph at Advisory 9, 105 mph at Advisory 10
The 100 mph figure came from Advisory 9, issued at 4 p.m. CDT, which opened with the line that Hurricane Hunters had found Isaias now had 100 mph winds and put the central pressure at 975 millibars. Six hours later the numbers had moved the wrong way for anyone on the coast. The 10 p.m. CDT Public Advisory 10 places the center near 25.4 degrees north, 88.4 degrees west, roughly 260 miles south of the mouth of the Mississippi River, moving northeast at about 14 mph.
The advisory text has hurricane-force winds reaching out up to 25 miles from the center, while tropical-storm-force winds extend as far as 125 miles. Those radii put the strongest winds close to the core, so the stretch of shoreline that takes the eyewall will see conditions very different from towns farther out.
Forecaster Reinhart wrote in the 10 p.m. forecast discussion that the maximum winds were raised to 90 knots, the equivalent of 105 mph, and that further strengthening is possible overnight. The discussion allows a brief peak near 100 knots, about 115 mph and the major-hurricane threshold, early Friday, before southwesterly wind shear begins to weaken the storm ahead of landfall.
The hurricane warning from Ocean Springs to the Bay/Gulf County line
The warning that gives this storm its map is the hurricane warning running from Ocean Springs, Mississippi, to the Bay/Gulf County line in Florida. Advisory 10 states there were no changes to the watches and warnings from the previous package, so the endpoints that were in effect at Advisory 9 still apply. A tropical storm warning flanks the hurricane warning on both sides, from the Jefferson/Plaquemines Parish line in Louisiana to west of Ocean Springs, and from the Bay/Gulf County line east to the Aucilla River in Florida.
The NHC home page carried the banner that Isaias is expected to approach the northern Gulf Coast as a dangerous hurricane on Friday, with the storm surge and hurricane warnings remaining in effect.
Storm surge of 5 to 7 feet from Dauphin Island to Indian Pass
Water is the hazard the advisory ranks first. A storm surge warning covers the coast from the mouth of the Mississippi River to the Suwannee River in Florida, and a storm surge watch extends from the Suwannee River to Yankeetown. Advisory 10 forecasts peak inundation of 5 to 7 feet above ground between Dauphin Island, Alabama, and Indian Pass, Florida, with lower amounts elsewhere, and warns that the timing of the surge relative to high tide will decide how much land floods.
The NHC says on its storm surge overview that surge is currently the leading cause of fatalities from hurricanes. The same page lists what raises it: higher wind speed, a perpendicular approach to the coast, a wide and gently sloping continental shelf and a concave shoreline. The National Weather Service office in Mobile and Pensacola described the same 5-to-7-foot figure on its local Isaias page as life-threatening surge, expected to peak Friday night and subside by Saturday morning.
Landfall timing and the forecast track across Alabama
Hurricane conditions are expected in the warning area Friday night into early Saturday, with tropical-storm conditions arriving earlier on Friday. Isaias is forecast to turn north on Friday and accelerate. The discussion’s 24-hour point, valid at 7 p.m. CDT Friday, places the center at 29.9 north, 87.1 west, just offshore of the Alabama-Florida line, still at 85 knots, or about 98 mph.
By the 36-hour point, 7 a.m. CDT Saturday, the track has the center near 32.2 north, 87.3 west over central Alabama with winds down to 45 knots, about 52 mph, and the 48-hour point shows a post-tropical remnant still over Alabama. The Weather Prediction Center’s extended rainfall discussion, issued at 4:23 p.m. EDT Thursday, puts the expected landfall near the Alabama-Florida border.
The next update is an intermediate advisory at 1 a.m. CDT, followed by the full 4 a.m. CDT advisory. The discussion left open the chance of strengthening overnight, so the 105 mph reading at 10 p.m. may not be the peak before the warning area sees its first hurricane-force gusts.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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