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.
A storm surge watch is in effect along the US gulf coast, from Crystal River to the mouth of the Mississippi River.
Subtropical Storm Alberto is delivering heavy rain and gusty winds to Florida on Sunday morning with current projections showing the storm making landfall in the Panhandle as a tropical storm tomorrow.
Local emergency officials continue to monitor flood-prone areas, but so far no issues have been reported. Gradual strengthening is expected, although Alberto is not forecast to become a hurricane.
At the moment its growth is being hindered by strong winds in the upper atmosphere, but as the storm tracks northwards these winds are expected to ease, allowing the storm to complete its transition into a fully tropical system.
Another 1 to 2 inches of rain is expected through Sunday in the Manatee-Sarasota area, though specific areas could receive much more.
Alberto's projected storm track has shifted eastward since Friday, lessening its threat to the active oil production areas in the Gulf of Mexico.
Image By NOAA
Alberto is the first major storm of the 2018 hurricane season, which runs through the fall and often brings heavy storm damage to the Gulf Coast and southeastern United States. The forecast from the Weather Prediction Center still estimates up to 4 inches or more of rain could fall in Volusia County, where a flood watch is in effect. There were no immediate reports of emergencies.
"We can not rule out the possibility of this system becoming a hurricane before it makes landfall sometime on Monday or Monday evening", according to AccuWeather meteorologist Dan Kottlowski.
As several states in the Southeast declare emergencies ahead of Subtropical Storm Alberto, forecasters in Upstate New York are tracking its progress northward.
Many may see some tropical storm force wind gusts along the coast but not necessarily sustained winds.
"So we need to really be careful with that rainfall", Graham said.
A Tropical Storm Watch has been issued for the west coast of the Florida peninsula from Boca Grande to Anclote River.
Flash flooding and even tornadoes are possible due to the storms hitting Florida from Alberto.