CSU Forecasters Warn October Could See 'Major Hurricane'
With more than a month left in the 2005 Atlantic hurricane season, Colorado State University forecasters said Monday that the United States isn't out of the woods yet. In fact, they project that October will continue the trend of above-average activity that has already been witnessed in the preceding four months of the hurricane season.
CSU forecasters William M. Gray and Philip J. Klotzbach said that while the 2005 Atlantic basin hurricane season has been one of the most active and is already the most destructive season on record, their October-only forecast calls for three named storms, two hurricanes, one major hurricane and net tropical cyclone (NTC) activity of 30, which is well above the mean October-only average value of 18.
"We expect that by the time the 2005 hurricane season is over, we will witness seasonal tropical cyclone activity at near-record levels," the forecasters said. They note that their August-only and September-only forecasts verified "remarkably well." The hurricane season runs from June 1 to Nov. 30 every year.
As of the end of September, the 2005 hurricane season has had 17 named storms, nine hurricanes and five major hurricanes. Three major hurricanes have made United States landfall (Dennis, Katrina and Rita), and Ophelia struck the North Carolina coastline (although the eye passed just offshore) as a Category One storm. Hurricane Katrina became the most destructive storm on record after coming ashore in Southeast Louisiana as a Category Four storm and devastating the Louisiana, Mississippi, and Alabama coastline.
"We expect October activity to be above its climatological average," the forecasters said. "We assume no activity in November. A seasonal verification of all 2005 activity will be issued on Friday, November 19."
As for landfall possibilities, the forecasters are predicting an above average probability in October when compared to a 1950-2001 dataset. The probability of a named storm making landfall in October is 49% and the probability of a hurricane making October landfall is 21%. The probability of an intense hurricane (Categories Three-Five) making landfall during the month is 15%.
"The 2005 hurricane season has been a very active one," the forecasters said. "We expect total storm activity to reach near-record levels by the time the season ends on November 30. June-July 2005 had the most early-season tropical cyclone activity on record (seven named storms, two hurricanes, two intense hurricanes and an NTC of 68). August and September have also been quite active with the two months accruing an NTC of 115 (compared with the 51-year August-September average of 75)."
The forecasters said several factors were responsible for the very active Atlantic season this year. They include:
- Warmer Atlantic sea surface temperatures (SST);
- Lower Atlantic sea level pressures (SLP);
- Lower vertical wind shear; and
- Moister lower and middle atmosphere.
Gray and Klotzbach said this year's major hurricanes and last year's four U.S. landfalling major hurricanes continue to bring up questions concerning the role that global warming might be playing. The forecasters noted that the ideas that global warming may have been partly responsible for the last two years of greater landfalling hurricane activity has been enhanced by two recent papers presenting data to show that global tropical cyclones have become more intense in recent years. They speculate that this increased hurricane activity may be due to human-induced global warming.
The forecasters said their research finds no such correlation. "We believe that there is likely little or no relationship between the small observed warming of the globe over the past thirty years and changes in global tropical cyclone activity or intensity," they said.
Copyright 2005 Intelligence Press Inc. All rights reserved. The preceding news report may not be republished or redistributed, in whole or in part, in any form, without prior written consent of Intelligence Press, Inc.