Revision increases expected hurricanes
The 2012 hurricane season could still have another six to 11 named storms by the time it comes to a close on Nov. 30, based on an updated forecast from the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
The new forecast released Thursday increases the total number of storms, calling for 12 to 17 named storms for the entire hurricane season, with five to eight of them being hurricanes with top winds of 74 mph or greater. Of those hurricanes, two or three of them could develop into major hurricanes with winds of at least 111 miles per hour.
The preseason forecast released in May called for nine to 15 storms, four to eight hurricanes with one to three becoming major hurricanes.
The updated forecast includes the six named storms that have already formed this season, tropical storms Alberto, Beryl, Debbie and Florence, and hurricanes Chris and Ernesto. A tropical depression in the Atlantic Ocean on Thursday will be called Gordon if it develops into a storm.
The reason for the forecast increase includes factors including the timing of the formation of an El Niño weather pattern, said Gerry Bell, lead hurricane season forecaster with NOAA’s Climate Prediction Center.
“In May we were uncertain about an El Niño impact,” Bell said.
El Niño is a warmer-than-normal sea-surface temperature in the Pacific Ocean that can create more upper atmospheric winds known as wind shear over the Gulf of Mexico and Atlantic Ocean. This wind shear can hamper the development of storms or even prevent tropical storms from forming.
Earlier this year, it was thought that the El Niño could form earlier in the season and be a detriment to formation of storms. However, more-recent El Niño forecasts show that it will likely develop in August or September, Bell said. Since it can take several weeks for the effects of El Niño to be seen, the higher wind shear expected will occur later in the season.
“Usually there’s a time delay of several weeks between when these conditions form and when the effects are felt,” Bell said.
Another reason for the increase in forecasted storms is the early-season activity in the deep Atlantic Ocean.
“It’s just another indicator that conditions are favorable for (storm) development,” Bell said.
The third factor is that the Atlantic Ocean is continuing within the more-active cycle of the multidecade hurricane cycle. This current more-active part of the cycle started in 1995 and followed a low-activity era that ran from 1971 to 1994, according to NOAA.
Although hurricane season runs from June 1 through Nov. 30, tropical storms can form earlier, like they did this year with two storm forming in May. However, the peak of the hurricane season normally runs between August and October, Bell said.
Laura Furgione, acting director of NOAA’s National Weather Service, urged people to be prepared. Even if people live hundreds of miles inland from the coast, she urged people to be prepared for inland flooding.
“Inland flooding is the most-dangerous impact of hurricanes,” she said.