Franklin County, in the Florida Panhandle, has issued a mandatory evacuation for its barrier islands in the Gulf of Mexico affecting some 4,200 housing units, while Taylor County, to the east, has a voluntary evacuation order in place for its coastal areas.
Hurricane season doesn't officially begin until June 1, but Alberto apparently missed the memo.
Florida, Alabama and MS declared states of emergency on Saturday with up to 15 inches (38 cm) of rain forecast over the Memorial Day weekend, as well as tidal surges and damaging winds, according to Patrick Burke of the weather service's Weather Prediction Center in College Park, Maryland.
At 11 a.m. ET Sunday, the National Hurricane Centre said Alberto was about 210 kilometres west-southwest of Tampa, Fla., and moving north at 22 km/h.
You'll likely have to adjust those weekend grilling plans for this Memorial Day weekend: As Subtropical Storm Alberto makes its way north through the Gulf of Mexico, sloppy, wet and potentially risky conditions are expected through Monday.
This is still a developing weather situation, so pay close attention to the weather, especially over the next 48 hours.
"As we continue to monitor Subtropical Storm Alberto's northward path toward Florida, it is critically important that all Florida counties have every available resource to keep families safe and prepare for the torrential rain and severe flooding this storm will bring". A tropical storm warning has been issued for the Dry Tortugas. The threat of storms through the end of the week makes this a definitely possibility.
Alberto is expected to strengthen until it reaches the northern Gulf Coast, likely on Monday night.
Rain is considered the main threat here, with downpours possible through Sunday, then becoming more scattered.
About 130 to 250 millimetres of rain are possible along affected areas in eastern Louisiana, Mississippi, Alabama, western Tennessee and the western Florida Panhandle.
Live video from webcams posted in Clearwater and Destin showed half-empty beaches, and whitecaps roiled the normally placid Gulf waters.
Alberto is expected to produce heavy rainfall and flooding over western Cuba, South Florida and the Florida Keys, the National Hurricane Center said Sunday. Timing so far seems to be around 12-1PM Monday.
Jeffrey Medlin, meteorologist in charge in Mobile, says even after the storm moves north there will still be swells coming up from the south. Just because it's "nice and sunny" after the storm passes, Medlin said, there's still a risk for swimmers. Anyone thinking about going out onto the water is urged to use caution.