Tropical Storm Isaias Prompts Hurricane Watch for Northern Gulf Coast

By
Harris
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28

Key Points

  • The National Hurricane Center issued a Hurricane Watch from Bay St. Louis, Miss., to Indian Pass, Fla., at 10 a.m. CDT Wednesday, the first U.S. watches for Isaias.
  • A Storm Surge Watch covers the coast from the mouth of the Mississippi River to Yankeetown, Fla., with 5 to 7 feet of surge possible from Ocean Springs, Miss., to Indian Pass and in Mobile Bay.
  • Isaias had 45 mph winds about 540 miles south-southwest of the mouth of the Mississippi and is forecast to become a strong hurricane before reaching the northern Gulf Coast on Friday.
  • Forecasters expect 3 to 6 inches of rain, locally up to 10 inches, from far southeastern Louisiana to the Florida Panhandle from Friday through the weekend.
  • Florida Gov. Ron DeSantis has declared a state of emergency for 25 counties, FOX Weather reported.

Hurricane and storm surge watches are now up along the northern Gulf Coast as Tropical Storm Isaias gets better organized in the southern Gulf. The National Hurricane Center says Isaias is expected to strengthen rapidly and could be a strong hurricane by the time it nears the coast of Mississippi, Alabama and the Florida Panhandle on Friday.

What happened

In its 10 a.m. CDT advisory on Wednesday (11 a.m. EDT), the hurricane center issued three sets of coastal watches:

  • Hurricane Watch: Bay St. Louis, Miss., to Indian Pass, Fla.
  • Storm Surge Watch: the mouth of the Mississippi River to Yankeetown, Fla.
  • Tropical Storm Watch: the Jefferson/Plaquemines Parish line in Louisiana to west of Bay St. Louis, and east of Indian Pass to the Aucilla River in Florida.

A hurricane watch means hurricane conditions are possible in the area. NHC says it is typically issued 48 hours before tropical-storm-force winds are first expected, since those winds make outside preparations difficult or dangerous. The center added that more watches and warnings could be needed for part of the U.S. northern Gulf Coast later Wednesday.

The storm grew out of the disturbance we first covered on Monday, when forecasters were still tracking a likely tropical depression in the Gulf. Tropical Depression Nine formed Tuesday afternoon and was named Isaias early Wednesday.

Latest development

At 10 a.m. CDT, an Air Force Reserve Hurricane Hunter aircraft located the center of Isaias about 260 miles west-northwest of Progreso, Mexico, and about 540 miles south-southwest of the mouth of the Mississippi River. Maximum sustained winds had risen to 45 mph, up from 40 mph six hours earlier, and the storm was moving east-northeast at 8 mph. Dropsonde data put the minimum pressure at 1000 mb.

NHC expects Isaias to turn northeast and then north on Thursday and Friday, passing north of the Yucatan Peninsula on Thursday. “Isaias is expected to strengthen into a strong hurricane before approaching the northern Gulf Coast on Friday,” forecasters wrote in their forecast discussion. The official forecast peaks Isaias near 110 mph over the central Gulf early Friday. Increasing wind shear near landfall could cause some weakening, but NHC says it is not certain how fast the winds will drop, and the storm should grow in size as it approaches the coast.

The track is not settled. NHC says computer models remain “somewhat split,” and its new forecast was nudged slightly east. Many of the stronger solutions are on the eastern half of the guidance and faster, which is why a range of watches was issued now.

Why it matters

Isaias is expected to become the first hurricane of the 2026 Atlantic season, according to The Weather Channel, and it is aimed at a densely populated stretch of the Gulf Coast. NHC lists these possible storm surge heights above ground if the peak surge arrives at high tide:

  • Ocean Springs, Miss., to Indian Pass, Fla.: 5 to 7 feet
  • Mobile Bay: 5 to 7 feet
  • Mouth of the Mississippi River to Ocean Springs: 3 to 5 feet
  • Indian Pass to the Aucilla River, Fla.: 3 to 5 feet
  • Aucilla River to Yankeetown, Fla.: 2 to 4 feet
  • Lake Pontchartrain: 1 to 3 feet

The deepest water is expected near and east of where the center comes ashore. Residents in the surge watch area should follow local officials and evacuate if told to do so, NHC says. It also warns that the risk of damaging hurricane-force winds is rising for the Florida Panhandle, southern Alabama and Mississippi, and that people there should prepare for long power outages.

Rain will reach well inland. NHC forecasts 3 to 6 inches, with local totals up to 10 inches, from far southeastern Louisiana to the Florida Panhandle from Friday through the weekend, and 1 to 3 inches, locally 5, across much of the Southeast as far north as the Tennessee Valley and the Carolinas. Flash and urban flooding and isolated river flooding are possible. Swells reaching the Gulf Coast late this week are likely to cause life-threatening surf and rip currents.

States are already preparing. Florida Gov. Ron DeSantis signed an executive order declaring a state of emergency for 25 counties in the Panhandle and Big Bend region, FOX Weather reported.

What happens next

  • Timing: Tropical storm conditions could begin in the watch areas midday Friday, and hurricane conditions could begin in the hurricane watch area late Friday, according to NHC.
  • Next advisories: NHC will issue an intermediate advisory at 1 p.m. CDT (2 p.m. EDT) and a full advisory at 4 p.m. CDT (5 p.m. EDT) Wednesday. Watches could be extended or upgraded to warnings.
  • Prepare now: People along the coast from Louisiana to the Florida Big Bend should check their hurricane plan, follow their local National Weather Service office and emergency managers, and use the checklists at Ready.gov.

Related live coverage

Track Isaias and other severe weather on our U.S. Weather Live center, or find national news channels on the Watch Live News hub.

Sources