Tropical Storm Alex, the first named storm of the Atlantic hurricane season, formed Sunday morning in the Gulf of Mexico on a track to come ashore in southern Florida with heavy rains and gusty wind.

National Hurricane Center forecasters said in a 5 am advisory that Alex had sustained winds of 50 mph (80 kph) and was located about 270 miles (435 kilometers) northeast of Fort Pierce, Florida.

Parts of South Florida were experiencing road flooding from heavy rain and wind Saturday. Officials in Miami warned drivers about road conditions as many cars were stuck on flooded streets.

“This is a dangerous and life-threatening situation. Travelling during these conditions is not recommended. It’s better to wait. Turn around, don’t drown,” the city of Miami tweeted.

Alex is a new version of the storm that was called Hurricane Agatha when it slammed into Mexico’s Pacific Coast earlier this week, killing at least 11 people and leaving 20 missing. It got a new name once the storm crossed Mexico into the Atlantic basin.

A tropical storm warning was in effect for Bermuda.

In Cuba, the storm killed three people, damaged dozens of homes in Havana and cut off electricity in some areas, according to authorities. Heavy rainfall continued Saturday, but was diminishing as the weather system moved away from the island.

The Atlantic hurricane season officially began Tuesday. This is an unusually early start to the storm season but not unprecedented for Florida.

The National Hurricane Center predicted rainfall up to 10 inches (25 centimeters) was possible in South Florida, including the Florida Keys. The storm was not expected to produce huge winds or major storm surge. But local flooding was likely.