A strengthening Tropical Storm Sandy, set to slam Jamaica as a dangerous and drenching Category 1 hurricane, also promises to bring foul weather to South Florida in coming days.

Early Wednesday, the National Hurricane Center placed much of Southeast Florida, from the Middle Keys to Jupiter, under a tropical storm watch. While Sandy’s most damaging winds were expected to remain offshore, its sprawling outer bands could sweep the South Florida coast Thursday and Friday as it churns through the Bahamas. The forecast for South Florida calls for blustery weather: 25- to 35-mph winds, with gusts to 50 mph, as well as pounding, beach-chewing waves and fast-moving thunderstorms.

NOT TAKING CHANCES

The impact could be worse in Jamaica and eastern Cuba, both under hurricane warnings for the late-season storm. At 8 a.m., the hurricane center said Sandy had 70 mph sustained winds, just on the cusp of hurricane strength, and located 95 miles south of Kingston, Jamaica’s capital city.

Across Jamaica, already experiencing pelting rains and howling winds, poor people in ramshackle shantytowns and wealthier residents alike were worried. Many sections of the debt-shackled country have crumbling infrastructure, and a lack of building codes has resulted in some middle-class homes and tin-roofed shacks being built close to steep embankments and gullies vulnerable to flash floods and mudslides.

In the hilly community of Kintyre, near the capital of Kingston, Sharon Gayle and a few of her drenched neighbors expected to lose the town’s bridge over the Hope River, which washed away a section of the span just three weeks ago during a heavy downpour.

"We’ve gotten cut off here a whole heap of times. But with a big nasty hurricane on the way, I’m really nervous. We’re trying not to show it in front of the children though," said the mother of three, huddling under a sopping white towel as she stared at the rising river.

Kingston’s streets were jammed on Tuesday as residents rushed to stock up on food, fill gas tanks and pick up children at schools closed early for the approaching storm.

In the northeastern parish of Portland, resident Ryan Amos joined neighbors in stocking up on canned goods and supplies. He was bracing for a direct hit from a storm that forecasters said could dump six to 12 inches across much of the mountainous island, with 20 inches or more in spots — volumes that have triggered deadly river overflows, flash floods and mudslides in past storms.

“Portland has a tendency to have massive floods throughout the parish,” Amos said. “The sense that I am getting is that people fear that this storm is going to hit us directly and no one is taking any chances.”

Forecasters at the National Hurricane Center said Sandy was likely to continue to intensify for at least one more day before it begins to encounter strong wind shear that could weaken it. The storm, moving north at 14 mph, was on track to pass over central Jamaica later Wednesday, likely as a Category 1 hurricane with 80 mph winds, and remain a hurricane as it hits eastern Cuba later in the night.

Jamaica’s two international airports prepared to close, cruise ships changed their itineraries and police ordered 48-hour curfews in major towns to keep people off the streets and deter looting as the late-season storm was expected to rake Jamaica from south to north at midday.