National Oceanic and Atmospheric Administration forecasters predict a busy Atlantic hurricane season is ahead.
They are calling for 45 percent chances of an active year in the tropics, 35 percent chances of a typical year and only 20 percent chances of a below-normal season.
That is counter to earlier forecasts of a below-normal season, based on expectations that the climate phenomenon known as El Niño was developing.
Gerry Bell, NOAA's lead seasonal hurricane forecaster, said the outlook "reflects our expectation of a weak or non-existent El Niño" and normal or warmer-than-normal water temperatures across the tropical Atlantic and Caribbean Sea.
Forecasters predict 70 percent chances that 11 to 17 named storms will form; that five to nine of them will become hurricanes; and that two to four of those will become major hurricanes.
In a typical season, there are a dozen named storms, which have winds of at least 39 mph; six hurricanes, with maximum winds of at least 74 mph; and three major hurricanes, with at least 111 mph winds.
Early forecasts that AccuWeather.com and the Tropical Meteorology Project at Colorado State University released in early April called for a quieter season, with 10 or 11 named storms and four to six hurricanes. But that was when it appeared a potentially moderate El Niño pattern was going to develop.
Now, forecasters think El Niño may not develop this year, or if it does, that it will be weak. El Niño is marked by warmer-than-normal waters in the Pacific Ocean that triggers weather extremes around the world, and is known for inhibiting formation and development of tropical cyclones in the Atlantic.
Weather and emergency officials urged residents to begin preparing for the possible strong winds, flooding and power outages that tropical storms and hurricanes can bring.
"Regardless of how many storms develop this year, it only takes one to disrupt our lives," acting FEMA Administrator Robert J. Fenton, Jr. said.
Hurricane season officially runs from June 1 to Nov. 30. There is already one storm to tally even before that — Tropical Storm Arlene, a rare pre-season storm, formed over the eastern Atlantic last month.