The National Hurricane Center's latest data indicates a low-pressure system now over the northwestern Caribbean Sea has become "better defined" overnight, and could bring tropical-storm-force winds and storm surge to the northern Gulf Coast late this weekend or early next week.
Alberto had top sustained winds of 40 mph (65 kph) early Friday and was located 55 miles (90 kilometers) south of Cozumel, Mexico.
Tropical storm watches are in effect for Tulum to Cabo Catoche, Mexico, and the Cuban province of Pinar del Rio.
Locally, the storm will produce heavy bands of rain and storms as the center of circulation is set to impact in the Gulf Coast.
"The slow movement of the storm can allow heavy rain to persist over a part of the southeast through most of next week".
At the very least, several inches of torrential rain are likely across the Gulf states east of Texas. That would certainly mean a wet Memorial Day weekend in the New Orleans area and at Gulf Coast beaches in Mississippi, Alabama and Florida.
Subtropical Alberto set to drench Florida on Sunday, Monday
Hurricane season officially begins next Friday.
According to the NHC, the system could also bring tropical storm-force winds and storm surge to portions of the northern Gulf Coast by late this weekend or early next week. Subtropical storms can develop into tropical storms, which in turn can strengthen into hurricanes. This heavy rain could lead to flooding in vulnerable areas of Southwest Florida. The coastal Carolinas and southern Florida are expected to have more rain.
The "subtropical" designation is a nuance in the world of weather science.
Volatile upper-level winds are also preventing this system from developing into something stronger.
Last hurricane season - which produced the immensely destructive hurricanes Harvey, Irma, and Maria - was exceptionally active, said Bell, who doesn't now expect this season to produce such intense activity.
The NHC expects the storm to make landfall late Monday or early Tuesday around the MS or Alabama coast, at which point its strength should decrease and it will become a tropical depression.