Subtropical Storm Alberto Strengthens on Its Way to Northwest Florida

Subtropical Storm Alberto strengthened on Sunday as it moved closer to northwest Florida.  At 11:00 p.m. EDT on Sunday the center of Subtropical Storm Alberto was located at latitude 28.5°N and longitude 85.8°W which put it about 95 miles (155 km) south-southwest of Apalachicola, Florida.  Alberto was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and the were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 991 mb.  A Tropical Storm Warning was in effect for the portion of the coast from Suwannee River, Florida to the border between Alabama and Mississippi.

The circulation of Subtropical Storm Alberto became more organized on Sunday.  A band of showers and thunderstorms wrapped around the center of circulation.  A band of drier air wrapped around the circulation just outside the rainband.  The band of drier air kept the circulation from developing a completely tropical structure and the National Hurricane Center continued to classify Alberto as a subtropical storm.  Alberto moved closer to the center of an upper level low over the Gulf of Mexico.  The upper level winds were weaker near the center of the low and the vertical wind shear decreased.  An upper level ridge over the Florida peninsula enhanced upper level divergence to the east of Alberto and the surface pressure decreases on Sunday.

Subtropical Storm Alberto will move through an environment somewhat favorable for intensification on Monday.  Alberto will move over water where the Sea Surface Temperature is near 28°C.  The upper level low will continue to produce some vertical wind shear.  The band of drier air will limit the development of thunderstorms outside the primary rainband.  Some intensification is possible during the next 12 hours, but the wind shear and drier air should limit any strengthening.

The upper low and the ridge over Florida will steer Subtropical Storm Alberto slowly toward the northwest.  On its anticipated track the center of Subtropical Storm Alberto is expected to make landfall over northwest Florida on Monday.  Alberto will be capable of causing minor wind damage.  Wind blowing water toward the coast will produce a storm surge of up to 4 to 7 feet (1.3 to 2.3 meters).  Alberto will drop heavy rain over parts of the southeastern U.S. and flooding could occur in some locations.