MIAMI – Tropical Storm Katrina threatened to dump more than a foot of rain on parts of water-logged Florida as it approached the state yesterday, with forecasters expecting it to strengthen to a weak hurricane before hitting the coast.

Katrina was expected to strike Florida’s east coast early tomorrow.

Many in the area – hit by two hurricanes last year – didn’t seem too worried about the slow-moving storm whose worst threat appeared to be flooding. Hardware stores noticed a slight increase in sales, but there didn’t appear to be a crush of customers looking for plywood, water, and other supplies.

Only a handful of people were buying hurricane supplies at a Home Depot in Davie. When asked if he was scared about Katrina, Joel Litman said: “Not this one. I think the next one is going to be the big one.”

A 150-mile stretch of Florida’s coast including Miami, Fort Lauderdale, West Palm Beach, and Vero Beach was under a hurricane watch, meaning sustained winds of at least 74 mph were possible by tomorrow. The watch area also included inland Lake Okeechobee.

Broward County recommended that people evacuate barrier islands and lowlying regions, and some schools in the area were closing today and tomorrow.

Katrina formed yesterday over the Bahamas and was expected to cross Florida before heading into the Gulf of Mexico. It could dump 6-12 inches of rain in the state, with some spots getting up to 20 inches.

National Hurricane Center meteorologist Eric Blake said residents of threatened areas should consider putting up hurricane shutters, particularly in coastal and exposed areas. Storm surge flooding of 3 to 5 feet topped by battering waves is expected.

At the Century Village retirement community in West Palm Beach, roof repairs were recently completed after it was hit by hurricanes Jeanne and Frances last year.

“I don’t think anybody is really terribly concerned about this one, because it looks like it’s going to be a tropical storm,” vice president of the residents’ association, Jean Dowling, said. “Now if it turns into a full-fledged hurricane, then you’re going to see some scurrying.”

Because of Katrina, Governor Bush canceled a business trip to Peru that was to begin yesterday and planned to return to Florida from Virginia, where he was attending a hearing on military base realignment.

At 5 p.m. EDT yesterday, the season’s 11th named storm had top sustained winds of 45 mph. Katrina was centered about 185 miles east-southeast of the Florida coast and was moving northwest at 9 mph.

The Florida Panhandle was hit by Tropical Storm Cindy and Hurricane Dennis earlier this year. Early indications were that Dennis caused about $2 billion in total damage. Last year’s four hurricanes caused an estimated $46 billion in damage across the country.

In an average year, only a few tropical storms develop by this time in the Atlantic, Caribbean, and Gulf of Mexico. The Atlantic hurricane season began June 1 and ends November 30.

Wednesday was also the 13th anniversary of Hurricane Andrew’s landfall in the Miami area. It was the most expensive natural disaster in American history.