Note to Editors: The complete hurricane forecast report, related research, detailed descriptions of forecast factors, charts and previous forecasts will be available on the Web with the news release at http://www.newsinfo.colostate.edu or at http://hurricane.atmos.colostate.edu no later than 8:30 a.m. MST.
An extended-range forecast for 2008 calls for somewhat above-average Atlantic basin hurricane activity, according to a new report from the Tropical Meteorology Project at Colorado State University.
The report marks the 25th year of the CSU hurricane forecasting team, currently led by Phil Klotzbach and William Gray.
The team’s first extended-range forecast for the 2008 hurricane season anticipates 13 named storms forming in the Atlantic basin between June 1 and Nov. 30. Seven of the 13 storms are predicted to become hurricanes, and of those seven, three are expected to develop into intense or major hurricanes (Saffir/Simpson category 3-4-5) with sustained winds of 111 mph or greater.
"Based on our analysis of fall parameters, the 2008 Atlantic hurricane season is expected to be more active than the average 1950-2000 season," said Klotzbach, lead author of the forecasts.
This year’s prediction is based on a new statistical forecast technique that explains a considerable amount of hurricane variability in hindcasts issued from 1950-2007. Over this time period, the three-predictor scheme correctly forecast above- or below-average seasons in 45 out of 58 years.
The entire 28-page forecast report is available on the Web at http://hurricane.atmos.colostate.edu.
"Despite fairly inactive 2006 and 2007 hurricane seasons, we believe that the Atlantic basin is still in an active hurricane cycle," Gray said. "This active cycle is expected to continue at least for another decade or two. After that, we’re likely to enter a quieter Atlantic major hurricane period like we experienced during the quarter-century periods of 1970-1994 and 1901-1925."
The CSU hurricane forecast team also predicts a 60 percent chance that at least one major hurricane will make landfall on the U.S. coastline in 2008. The long-term average probability is 52 percent.
For the U.S. East Coast, including the Florida Peninsula, the probability of an intense hurricane making landfall is 37 percent (the long-term average is 31 percent). For the Gulf Coast from the Florida Panhandle west to Brownsville, the probability is 36 percent (the long-term average is 30 percent).
The team predicts above-average major hurricane landfall risk in the Caribbean.
Along with today’s report, the team has updated the Landfall Probability Web site that provides probabilities of tropical storm-force, hurricane-force and intense hurricane-force winds making landfall at specific locations along the U.S. East and Gulf Coasts within a variety of time periods. U.S. landfall probabilities are available for 11 regions, 55 sub-regions and 205 individual counties along the U.S. coastline from Brownsville, Texas, to Eastport, Maine.
The Web site, available to the public at http://www.e-transit.org/hurricane, is the first publicly accessible Internet tool that adjusts landfall probabilities for regions, sub-regions and counties based on the current climate and its projected effects on the upcoming hurricane season. Klotzbach and Gray update the site regularly with assistance from the GeoGraphics Laboratory at Bridgewater State College in Massachusetts.
The hurricane team’s forecasts are based on the premise that global oceanic and atmospheric conditions – such as El Nino, sea surface temperatures and sea level pressure – that preceded active or inactive hurricane seasons in the past provide meaningful information about similar trends in future seasons.
For 2008, Gray and the hurricane forecast team expect continued fairly warm tropical and north Atlantic sea-surface temperatures, prevalent in most years since 1995, as well as neutral or weak La Nina conditions – a recipe for enhanced Atlantic basin hurricane activity. These factors are similar to conditions that occurred during the 1953, 1956, 1989, 1999 and 2000 seasons. The average of these five seasons had above-average activity.
The team will issue seasonal updates of its 2008 Atlantic basin hurricane activity forecast on April 8, June 3, Aug. 5, Sept. 2 and Oct. 2. The August, September and October forecasts will include separate forecasts for August, September and October-November activity.