Miami ? Florida residents rushed to fill their prescriptions and stood in long lines for gasoline, food and other supplies Monday as officials warned people not to wait for Tropical Storm Ernesto to become a hurricane again before taking precautions.

Forecasters said Ernesto could grow back into a hurricane in the warm waters off Cuba and come ashore in South Florida as early as tonight, exactly one year after Hurricane Katrina pummeled the Gulf Coast.

It would be the first hurricane to hit the United States this year.

Memories of Katrina and the seven hurricanes that have struck Florida since 2004 were fresh in the minds of many.

“Make sure you have the supplies for the 72 hours after the storm,” Gov. Jeb Bush warned from Tallahassee, a day after declaring a state of emergency for all Florida. “A hurricane’s a hurricane, and it has a devastation we’ve already seen. All you have to do is rewind to last year and see.”

About 400 miles of the state’s densely populated Atlantic coast and the Keys were under a tropical storm warning and hurricane watch in Ernesto’s path. A tropical storm warning and hurricane watch was extended from Vero Beach on Florida’s Atlantic side to Bonita Beach on the Gulf coast.

At 10 p.m. CDT, the fifth named storm of the hurricane season had top sustained winds of 40 mph, 1 mph above the minimum to be a tropical storm and down from hurricane-strength 75 mph Sunday, the National Hurricane Center said. It was centered over Cuba, about 20 miles north of Camaguey, and about 325 miles southeast of Key West and 320 miles south-southeast of Miami. It was moving west-northwest near 12 mph.

Over the weekend, Ernesto became the first hurricane of the Atlantic season and lashed the Dominican Republic and Haiti. One person was killed along Haiti’s southern coast.

There were no immediate reports of any damage or injuries in Cuba. The government regularly undertakes mass evacuations before tropical storms and hurricanes. This time, Cubans moved cattle to higher ground, tourists were evacuated from hotels, and baseball games were rescheduled for earlier in the day.

The Bahamas on Monday ordered boats in southern islands to stay in port. The island chain had a tropical storm warning and a hurricane watch in effect for western islands close to Florida’s coast.

In the Keys, visitors were ordered out, and authorities planned to evacuate sick and elderly people to Miami. Mobile home residents in the Keys were also urged to clear out. Miami-Dade County opened a shelter for people from the Keys.