Note to Editors: The complete hurricane forecast, a detailed description of forecast factors, press releases, downloadable broadcast-quality audio clips and video clips will be available on the Web at 8 a.m. Mountain Time on May 28 at www.colostate.edu.
In their final forecast update before the official start of the hurricane season on June 1, Colorado State University tropical cyclone researcher William Gray and his hurricane forecast team maintain their predictions for above-average Atlantic basin hurricane activity in 2004.
As detailed in today’s updated Atlantic seasonal hurricane activity forecast (May 28), Gray and his colleagues call for a total of 14 named storms to form in the Atlantic basin this year. Of these, eight are predicted to become hurricanes and three are anticipated to evolve into intense hurricanes (Saffir/Simpson category 3-4-5) with sustained winds of 111 mph or greater. The long-term average is 9.6 named storms, 5.9 hurricanes and 2.3 intense hurricanes per year.
These forecasts numbers are exactly the same as the team’s April 2 forecast. The team’s early December extended range forecast called for 13 named storms, seven hurricanes and three intense hurricanes.
"Global predictors obtained and analyzed through this point in May consistently point to the 2004 Atlantic basin hurricane season being an active one," Gray said. "We expect tropical cyclone activity to be well above average with about 145 percent of the average seasonal activity."
The Colorado State forecast team also continues to warn of the considerably higher than average probability of at least one intense (or major) hurricane making landfall in the United States this year. According to today’s forecast, there is a 71 percent chance of an intense hurricane hitting somewhere along the U.S. coastline in 2004 (long-term average is 52 percent). For the U.S. East Coast, including the Florida Peninsula, the probability of an intense hurricane making landfall is 52 percent (long-term average is 31 percent). For the Gulf Coast from the Florida Panhandle westward to Brownsville, Texas, the probability is 40 percent (the long-term average is 30 percent). The team also calls for above-average major hurricane landfall risk in the Caribbean.
Gray believes the United States has been fortunate over the past few decades in experiencing only a few major hurricanes making landfall in Florida and along the East Coast. The last nine years have witnessed 122 named storms, 69 hurricanes and 32 major hurricanes in the Atlantic basin. During that period, only three of the 32 major hurricanes – Opal, Bret and Fran – crossed the U.S. coastline. Based on historical averages, about one in three major hurricanes comes ashore in the United States.
"We cannot say exactly when or where it will happen, but climatology will eventually right itself, and we must expect a great increase in landfalling major hurricanes," Gray said. "As a result, and with the large coastal population growth in recent decades, it is inevitable that we will see hurricane-spawned destruction in coming years on a scale many times greater than what we have seen in the past."
On a long-term basis, major hurricanes account for about a quarter of all named storms, but when normalized for population, inflation and wealth per capita, those storms cause about 85 percent of all tropical cyclone-spawned destruction.
The Colorado State team believes that the United States is in a new multi-decadal era for increased storm activity, and that 2004 will follow this active trend.
"The past nine years constitute the most active consecutive years on record for Atlantic basin tropical cyclone activity, and we believe that the United States has entered a new era of enhanced major hurricane activity," said atmospheric research scientist and forecast team member Philip Klotzbach. "Particularly along the East Coast, citizens should be prepared for two or three decades of increased major hurricane activity, which also means increased probability of landfalling hurricanes."
The forecast team does not anticipate El Nino conditions in 2004. The Colorado State forecast team also does not attribute changes in recent and projected Atlantic basin hurricane activity to human-induced global warming.
Gray and his team continuously work to improve their forecast methodologies based on a variety of climate-related global and regional predictors. For a detailed description of the forecast factors, visit the Web at http://typhoon.atmos.colostate.edu.
"We are continually making progress in improving statistical hurricane forecasting techniques and in better understanding why there is such variability in month-to-month and year-to-year Atlantic basin hurricane activity," Gray said. "Our ongoing forecast research is allowing us to continually improve hurricane prediction skill."
Gray and his forecast team will issue seasonal updates of the 2004 Atlantic basin hurricane activity on Aug. 6, Sept. 3 and Oct. 1. The August, September and October seasonal updates also will include the team’s new August-only, September-only and October-only forecasts of tropical cyclone activity.
In addition to Gray and Klotzbach, other team members include William Thorson, Amie Hedstrom and others.