Alberto is slated to hit land just west of Panama City, Fla. - which is predicted to get more than 6.5 inches of rain through Tuesday night, according to the National Weather Service's office in Tallahassee.
Swells generated by Alberto will continue to affect the eastern and northern Gulf Coast Tuesday, meteorologists said.
"We're not expecting the season to be one of the most active on record", said Gerry Bell, lead hurricane season forecaster with NOAA's Climate Prediction Center.
The storm is the first storm of this year's hurricane season, coming a few day before the season officially starts on June 1.
As Alberto moved inland, deprived of the warm waters that fuel tropical weather systems, the storm was expected to steadily weaken.
Even after this pulls away from us, scattered showers and storms will continue.More news: North Korea summit hopes soar as U.S. delegation visits
Subtropical Storm Alberto has maximum sustained winds of 45 miles per hour and is moving north at 9 miles per hour.
A tropical storm warning remains in effect for Santa Rosa and Okaloosa counties, as does a storm surge watch.
Some spots along the gulf coast could be hammered with more than a foot of rain, but that's not the only concern.
Alberto disrupted long Memorial Day holiday weekend plans along from Pensacola in the Florida Panhandle to Miami Beach and other areas along the northern Gulf Coast, forced beachgoers out of the the water and prompted evacuations of low-lying areas.
For those who wish to dip their toes in the water this week, be warned: Strong breezes will produce above-normal waves, ranging from 2 to 4 feet, and unsafe rip currents through midweek, forecasters said.
"Steady weakening is in the forecast as the system moves inland but will remain a big rain-maker of 4-8" with isolated amounts up to 12" will be possible through Tuesday near and along the storm "core" track.
Heavy rainfall and flash flooding were occurring over parts of the Florida Panhandle, the National Hurricane Center said. A storm's winds need to reach 74 miles per hour to be called a hurricane.
With such an early start to the season, it makes sense to be concerned. Some of the showers and storms could become locally heavy.