Wilma, Storm #21, Gains Strength

Tropical Storm Wilma gained strength Monday in the northwestern Caribbean, and was following a path that some forecasters believe could menace the Gulf Coast later this week as a hurricane.

Wilma is the 21st named storm of the season, tying the record for the most storms in an Atlantic season. The only other time that many storms formed since record keeping began 154 years ago was in 1933.

At 11 a.m. EDT, Wilma had top sustained winds near 45 mph, just above the threshold for tropical storms. It was centered about 220 miles south-southeast of Grand Cayman and moving southwest about 5 mph.

A hurricane watch was issued for the Cayman Islands, meaning hurricane conditions could be felt there within 36 hours. A tropical storm warning, meaning tropical storm conditions are expected within 24 hours, also was posted. A tropical storm warning was also issued for the Honduran coast.

The storm is expected to bring 4 to 6 inches of rain in the Cayman Islands and Jamaica, with as much as 12 inches possible in some areas, National Hurricane Center forecasters said.

"We will have to watch this storm, because later in the week and over the weekend, it could be trouble in the Gulf of Mexico," said CBS News Meteorologist George Cullen. "All indications are that it will probably pass along the shores of the Yucatan Peninsula ... It will probably become a hurricane."

But hurricane specialist Stacy Stewart said Wilma had shifted west of its previous path and could hit Mexico's Yucatan Peninsula, not the U.S. Gulf Coast. "At this time it doesn't appear it will be a major threat to the United States during the next five days," Stewart said.

Larry Lahiff, a meteorologist at the National Hurricane Center, warned that Wilma's path was still uncertain even if it reaches the Gulf: "Usually when a storm gets into the Gulf, it's going to hit somewhere. Where, that's too early to tell right now. Some models take it west, some take it north."

The U.S. Gulf Coast was already battered this year by Hurricane Katrina on Aug. 29. It killed more than 1,240 people and is expected to cause more than $34 billion in insured losses. Hurricanes Rita and Dennis have also battered the Gulf.

Since 1995, the Atlantic has been in a period of higher hurricane activity. Scientists say the cause of the increase is a rise in ocean temperatures and a decrease in the amount of disruptive vertical wind shear that rips hurricanes apart. Some researchers argue that global warming fueled by man's generation of greenhouse gases is the culprit.

Forecasters say the busy seasons are part of a natural cycle.

"Between the 70s and 80s, there was relatively light activity, and now in the 90s and 2000s, we've seen this increased cycle, so we're in it for the next 10-15 years at least," meteorologist Ron Goodman told CBS Radio News.

It's also difficult to know whether the Atlantic was even busier at any time before record keeping began in 1851. And satellites have only been tracking tropical weather since the 1960s, so some storms that just stayed at sea before then could have escaped notice.

The six-month hurricane season ends Nov. 30. Wilma is the last on the list of storm names for 2005; there are 21 names on the yearly list because the letters q, u, x, y and z are skipped.

"If we happen to have to go to another storm, we go to the Greek alphabet, so the next storm would be Alpha, and then Beta and Gamma," said Cullen.

That has never happened in roughly 60 years of regularly named Atlantic storms.

A tracking map on the hurricane center's wall already had Alpha, Beta, Gamma and Delta listed just in case they form.

Forecasters say they wouldn't be surprised if another storm formed this year, even though the official forecast only called for 21 named storms this year. Wind shear typically increases and sea temperatures usually fall toward the end of October in the Atlantic, hurricane specialist Richard Knabb said.

"But the western Caribbean is an especially favorable location for late season development because the water remains quite warm and the vertical shear often is not that strong down there, that far south. So conditions are still favorable down there sometimes in late October and into November," he said.