The National Hurricane Center (NHC) has just upgraded Tropical Depression 19 to Tropical Storm Sally. And they will likely upgrade it again to a Hurricane on Monday.
Miami and Tampa Bay radar currently show a defined center of circulation and deep convection across much of Florida Bay and the Florida Keys.
Sally’s Likely Landfall in Louisiana
On the forecast track, the center is forecast to move over the southeastern and eastern Gulf of Mexico later today and Sunday. Sally will then move over the north-central Gulf of Mexico Sunday night and Monday.
Maximum sustained winds have already increased to near 40 mph (65 km/h) with higher gusts. Sally will likely become a hurricane by late Monday. (Note how the S’s turn to H’s in the cone map above.)
Tropical-storm-force winds currently extend outward up to 80 miles (130 km) south and southeast of the center.
Intensity guidance is inching up some. Conditions over the eastern Gulf of Mexico make a hurricane likely at landfall. “In fact,” says the NHC, “the hurricane models show significant intensification of Sally. This will need to be closely monitored over the next 1-2 days.”
Sally should produce total rainfall of 3 to 6 inches with isolated 8 inch amounts over the Florida Keys through tonight. NHC expects 2 to 4 inches and isolated maximum amounts of 6 inches across southern Florida and the western Florida coast to Tampa Bay.
This rainfall will produce flash and urban flooding across Southern and Central Florida.
Through Tuesday, NHC expects Sally to produce rainfall of 3 to 6 inches with localized amounts of 8 inches along the Gulf Coast between Florida and SE Louisiana. NHC predicts 2 to 4 inches farther inland over far southern Alabama, Mississippi and southeast Louisiana.
NHC says, “This is expected to be a slow-moving system. Sally will likely continue to produce heavy rainfall and considerable flooding near the central Gulf Coast through the middle of next week. Flash, urban and rapid onset flooding along small streams and minor to isolated moderate flooding on rivers is likely.”
Jeff Lindner, Harris County Meteorologist says, “Nearly all guidance slows Sally to around 5mph as the system approaches the coast. That will result in prolonged impacts and potentially devastating amounts of rainfall.” Remember Harvey?
Even though Houston is outside of the cone of uncertainty today, stay alert. Remember how the tracks of Marco and Laura kept shifting hourly. The NHC cautions that “The average NHC track error at 96 hours is around 150 miles. In addition, winds, storm surge, and rainfall hazards will extend far from the center.”
Posted by Bob Rehak on 9/12/2020
1110 Days since Hurricane Harvey