James Spann: Unsettled weather ahead for Alabama; Helene now a tropical storm

UNSETTLED WEATHER AHEAD: A few strong thunderstorms are in progress over northwest Alabama this afternoon. The Storm Prediction Center maintains a marginal risk (level 1 out of 5) of severe thunderstorms for the Tennessee Valley through early tonight; heavier storms there could produce small hail and gusty winds. Otherwise, the sky is partly sunny across the state with temperatures mostly in the low 90s.

The weather will be wet Wednesday with occasional rain ahead of a surface front, and rain continues Thursday ahead of the tropical system in the Gulf. Rain will likely be heavy at times late Thursday and Thursday night, then will diminish Friday morning. We expect just a few scattered showers Friday afternoon and night.

A few scattered showers are possible over the weekend, but the rain won’t be widespread or heavy. Highs will be between 78 and 82 degrees.

TROPICAL STORM HELENE FORMS: Newly formed Tropical Storm Helene, with sustained winds of 45 mph, is about 175 miles south of the western tip of Cuba. The storm is moving west/northwest at 12 mph.

Satellite trends suggest that the shear over the system is beginning to decrease, and model guidance continues to show relatively low to moderate shear for the next 48 hours or so. In addition, oceanic heat content values are very high, and the system will be moving through an environment of upper-level divergence.

Therefore, significant strengthening is anticipated, and the National Hurricane Center intensity forecast shows the system reaching a peak intensity around 115 mph in 48 hours while over the eastern Gulf of Mexico.

There could be some increase in shear around the time the system reaches the coast; given its large size, it might weaken only slowly. As a result, there is still a risk that the system could reach the coast as a major hurricane.

The forecast track has changed very little. Landfall is forecast in the Florida Big Bend region southeast of Tallahassee Thursday evening.

Key messages:

• A hurricane watch remains in effect for the Gulf Coast of Florida from Englewood northward and westward to Indian Pass, including Tampa Bay.
• A tropical storm watch is in effect for the Gulf Coast of Florida from Indian Pass to the Walton/Bay County line and from north of Bonita Beach to south of Englewood.
• The main impact in terms of wind, storm surge, flooding and isolated tornadoes will be from Carrabelle to Cedar Key and down to Tampa Bay (the east side of the circulation).
• The central Gulf Coast (Gulf Shores to Panama City Beach) is on the good, west side of the circulation with an offshore flow. There will certainly be some rain and wind for places like Panama City Beach, Mexico Beach, Port St. Joe and Cape San Blas, but the big issues with dangerous storm surge will be east of there. The Alabama Gulf Coast, Pensacola, Navarre Beach, Fort Walton Beach and Destin will have breezy, showery weather but nothing dangerous based on the current forecast track.
• A 10- to 15-foot storm surge is forecast from the Ochlockonee River down to Chassahowitzka on the Florida coast. The storm surge around Tampa Bay is forecast to be 5-8 feet.

• The southeast corner of Alabama (around Dothan) could see wind gusts to 40-45 mph Thursday night. The rest of east Alabama will see gusts to 35 mph; gusts over the western half of the state will be 20-30 mph. Higher winds will be east of Alabama across Georgia.
• The eastern half of Alabama has potential for 4 inches of rain Wednesday through Friday morning; rain potential for the western counties is 2-3 inches. A flash flood watch has been issued for southeast Alabama.

• Tornadoes are not expected in Alabama. Any isolated tornadoes will be along the east of the center of circulation as Helene moves northward east of Alabama.
• The weather will improve across Alabama by midday Friday; we expect just a few scattered, light showers Friday night and Saturday. The weather won’t be bad at all for high school and college games in the state, but a passing shower can’t be ruled out. Wind will be less than 10 mph.

Remember, any tropical forecast can change. Watch for updates.

ON THIS DATE IN 1956: Hurricane Flossy made landfall near Destin as a Category 1 storm.

For more weather news and information from James Spann and his team, visit AlabamaWx.