Subtropical Storm Alberto has gained an early jump on the 2018 hurricane season, heading toward expected landfall sometime Monday on the northern Gulf Coast.

Though the Atlantic hurricane season doesn't officially start until Friday, Alberto has become the first named storm this year, throwing disarray into long holiday weekend plans along Florida's Gulf Coast.

At 11 p.m. EDT Sunday, Alberto was centered about 205 miles (330 kilometers) west of Tampa and had maximum sustained winds of 65 mph (100 kph) as it approached the northern Gulf of Mexico.

The National Hurricane Center in Miami says a tropical storm warning is in effect from the Suwannee River in Florida to the Mississippi-Alabama state line. A tropical storm warning was discontinued from Florida's Anclote River to the Suwannee River.