Dr Geoff Main

HELENE BECOMES A HURRICANE: Helene is now a hurricane with maximum sustained winds of 80 mph… The center is about 500 miles south southwest of Tampa.  The hurricane is moving to the north/northwest at 10 mph.  From NHC: Helene is expected to move through/over an environment of relatively low shear, strong upper-level divergence, and sea surface temperatures of 29-31 degrees Celsius, all of which should foster additional strengthening. Rapid Intensification (RI) indices indicate a high chance of RI during the next 24 hours, and as a result the NHC intensity forecast shows Helene becoming a major hurricane by tomorrow morning. There is still some uncertainty on exactly how strong Helene will get, and upward adjustments to the forecast intensity could be required in subsequent advisories if Helene rapidly intensifies more than forecast. Regardless, Helene is forecast to be a large major hurricane when it reaches the Big Bend coast of Florida. As a result, storm surge, wind, and rainfall impacts will likely extend well away from the center and outside the forecast cone, particularly on the east side. In addition, the fast forward speed while Helene crosses the coast will likely result in farther inland penetration of strong winds over parts of the southeastern United States after landfall, including strong gusts over higher terrain of the southern Appalachians. Landfall will likely come tomorrow evening on the Florida coast south of Tallahassee, and east of Apalachicola; Helene is expected to be a major hurricane (category three) with winds of 125 mph at that time. There has been very little change in the track forecast over the past 48 hours. Also, there has been very little change in the expected impact for inland areas.  Key messages… *A Hurricane Warning remains in effect from Anclote River to Mexico Beach. *A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor *The Central Gulf Coast (Gulf Shores to Panama City Beach) is expected to be on the good, west side of the circulation with an offshore flow. The hurricane warning includes Mexico Beach, Port St. Joe, Cape San Blas, and points east. The main impact in terms of wind, storm surge, flooding, and isolated tornadoes will be from east of Indian Pass to Cedar Key and down to Tampa Bay (the east side of the circulation). *A 10-15 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'. *The southeast corner of Alabama (around Dothan) could see wind gusts to 40/45 mph tomorrow night; a tropical storm warning has been issued for Houston and Henry counties. The rest of East Alabama will see gusts to 35 mph; gusts over the western half of the state will be in the 20-25 mph range. Highest wind velocities will be east of Alabama over North Florida and Georgia. *The eastern half of Alabama has potential for 3-5 inches of rain through Friday morning; rain potential for the western counties is 1-3 inches. Areas in West and Southwest Alabama from Tuscaloosa to Mobile are expected now to receive under one inch. A flash flood watch has been issued for East and Southeast Alabama, in the broad area from Gadsden and Anniston south to Dothan. *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 isolated, light showers Friday night and Saturday. Bottom line is that the weather won't be bad at all for high school and college games in the state, but just keep mind a passing shower can't be ruled out. Wind will be under 10 mph. Remember, any tropical forecast can change. Watch for updates!