Tropical Storm Wilma formed Monday in the northwestern Caribbean, tying the record for the most storms in an Atlantic season and 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. The only other time that many storms formed since record keeping began 154 years ago was in 1933. At 5 a.m. EDT, Wilma had top sustained winds near 40 mph, just above the threshold for tropical storms. It was centered about 175 miles southeast of Grand Cayman and drifting southwest near 3 mph. A hurricane watch was issued for the Cayman Islands, meaning hurricane conditions could be felt there within 36 hours. 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, forecasters said. Long-term forecasts show the storm heading into the Gulf of Mexico by the weekend. Forecasters said high water temperatures and other conditions were favorable for it to become a significant 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 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 at the National Hurricane Center say the busy seasons are part of a natural cycle that can last for at least 20 years, and sometimes up to 40 or 50. They say the conditions are similar to those when the Atlantic was last in a period of high activity in the 1950s and 60s. 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 any other storms form, letters from the Greek alphabet would be used, starting with Alpha. 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. Reprinted from yahoonews.com