Category 4 Irma expected to slam Keys by dawn

Slowed to a crawl by a violent encounter with the island of Cuba, Hurricane Irma nonetheless pressed on toward the Florida Keys Saturday night, with a landfall expected sometime Sunday morning.

Irma’s speed was cut in half and its intensity dramatically declined as it hammered Cuba, but the National Hurricane Center’s 8 p.m. advisory nonetheless warned that the decline is only temporary.

“Irma is forecast to restrengthen once it moves away from Cuba and remain a powerful hurricane as it approaches Florida,” the advisory said. As its 7 mph speed picks up, Irma could cover the 110 miles to Key West in a relatively short time.

From there, it will take a north-by-northwest track up Florida’s Gulf Coast, the hurricane center said. Miami and Fort Lauderdale have likely escaped the worst of its wrath, but the Tampa-St. Petersburg area — which hasn’t suffered a direct hit from a powerful hurricane in more than 90 years — may not be so lucky.

And because Irma is so big, pushing hurricane-force winds outward up to 70 miles from the center and tropical-storm force winds to 195 miles, it can wreak considerable havoc in Miami-Dade and Broward counties even from a distance.

A tornado was sighted in Oakland Park Saturday night, and the weather service issued tornado warnings for central Miami-Dade and western Broward. Miami-Dade Schools Superintendent Alberto Carvalho, visiting hurricane shelters located in his schools, warned residents against returning home.

“Despite the fact that we may not take a direct hit, the worst of the weather is yet to come,” he said. “Our advice is to stay put, stay where you are, driving conditions are going to be bad.”

The same cautions surely extended into the Keys, were Marathon International Airport was already logging sustained wind of 48 mph and a gust of 67 mph.

While the forecast track shows the storm’s center crossing south of Big Pine, fierce winds and storm surge will likely be widespread.

Waters should begin rising between 8 p.m. and 2 a.m. tonight along the eastern side of the islands and from 8 a.m. to 2 p.m. on the west side, said hurricane specialist Mike Brennan. The surge could go as high as 10 feet throughout the Keys. From Card Sound Road to Miami Beach, a four- to six-foot surge is possible, he said.

Ed Rappaport, the acting director of the hurricane center, said Hurricane Irma’s impending visit to the Florida Keys and the state’s west coast is “capable of causing loss of life and major damage.”

The storm’s center has slowed to a crawl, an indication that it has begun its long-awaited turn to the north and the Florida Keys. Rappaport said the Keys can expect five- to 10-foot surges with waves atop.

Tampa’s storm surge could be between five and eight feet.

“We could see Irma back to a Cat 4 by the time it reaches the Keys,” said Rappaport.

He said the island chain can expect 100 mile per hour winds or more by daybreak.

Rappaport said the water driven into the Florida Keys by Hurricane Irma could exceed the five to 10 foot storm surge predicted because there could be waves of equal height riding on top of the surge.

He also said the storm’s barometric pressure dropped slightly from this afternoon and its lack of forward motion meant the storm is adjusting and starting to head north.

As for the folks along the state’s west coast awaiting Irma, “I’m very concerned. They’re going to have a very rough 24 to 36 hours.”

Irma’s jog to the west caught much of the Gulf Coast by surprise. At midday Saturday, the plywood sheets and metal window shutters so ubiquitous in South Florida were still comparatively rare in St. Petersburg.

As for the Keys, their relationship with hurricanes is intimate and infamous, going back in recorded history at least to the early 17th century.

Over the past 100 years, the islands have been struck by a hurricane an average of one every 4.5 years — most disastrously on Labor Day weekend of 1935, when a nameless storm with 200 mph winds killed as many as 485 people and an entire railroad, the Keys extension of the the Florida East Coast Railway, which was totally wrecked and never rebuilt.