HOUSTON — The 2009 hurricane season is off to a slow start, but experts say the real activity usually doesn't begin until August.
Even though the first named storm in the Atlantic usually forms by July 10, the experts said, the early lull doesn't necessarily mean a weak overall season.
Thursday was the one-year anniversary of Hurricane Dolly, which when it struck south Texas became the Rio Grande Valley's most destructive storm in four decades.
A maturing El Nino in the Pacific Ocean, which tends to depress storm activity by 20 to 40 percent, makes the outlook for the rest of the season look promising.
But forecasters said it's no time to relax, and that El Nino years still can produce destructive storms.
The 2004 season didn't get its first storm until Hurricane Alex began developing on July 31. After Alex the season finished with 15 storms and six major hurricanes.
One of the three most-intense storms at a U.S. landfall, Hurricane Andrew, developed during an El Nino in 1992.
Some of the most famed storms to strike Texas and Louisiana have come during an El Nino, including the great storm of 1900, said Jill Hasling, president of Houston's Weather Research Center.
"There might be fewer storms during an El Nino," she told the Houston Chronicle for its Thursday editions. "But it only takes one."
Ten tropical storms or hurricanes develop during an average Atlantic season, but since 1995 the Atlantic has seen an upswing in activity. Most scientists attribute that to a long-term natural pattern.
The Atlantic hurricane season runs from June 1 to Nov. 30.