The 2008 Atlantic Basin hurricane season could be as active as ever, with 15 named storms expected, two Colorado State University scientists predicted on Apr. 9. Eight of those storms could be hurricanes and four of the eight could be intense hurricanes, they said.
“Current conditions in the Atlantic Basin are quite favorable for an active hurricane season,” said William Gray and Phil Klotzbach in their latest periodic analysis of trends contributing to storms in the tropical Atlantic Ocean, Gulf of Mexico, and Caribbean Sea. They added that they see a 69% chance of at least one major hurricane (Category 3 or stronger) making landfall on the US coastline.
Their forecast prompted US Sen. Mary L. Landrieu (D-La.) to reiterate her call for better hurricane impact preparedness. “We should bear in mind the lessons of 2005 and the catastrophic effects of Hurricanes Katrina and Rita. Preparedness is key in the face of a natural disaster, and 2½ years later we are still grappling with the consequences of ill-prepared agencies,” she said.
Current Atlantic Ocean surface temperatures are following a pattern which is typical prior to very active hurricane seasons, the researchers said. “Waters off the coast of Iberia as well as the eastern Tropical Atlantic are very warm right now. The Azores High has also been quite weak during the month of March. Typically, a weakened Azores High leads to weaker trade winds that enhance warm [sea surface temperature] anomalies due to reduced levels of evaporation mixing and upwelling in the eastern tropical Atlantic,” they observed.
Gray and Klotzbach’s latest forecast is an increase from one they issued on Dec. 7, 2007, in which they predicted there would be 13 named storms, seven hurricanes, and three intense hurricanes. Atlantic Basin cyclone activity averaged 9.6 named storms, 5.9 hurricanes, and 2.3 intense hurricanes from 1950 to 2000, they said.
They also questioned the idea that global warming has increased storm activity in the region. They conceded that there were more hurricanes in the Atlantic Basin from 1995 through 2007 (an average of 3.8/year) than there were in the previous 25 years (1970-94 where there were an average 1.5/year). But they traced the increase to rising thermohaline circulation and growing salinity in the Atlantic over several decades, which they said is not directly related to rising global temperatures.
“There have been similar past periods (1940s and 1950s) when the Atlantic was just as active as in recent years. For instance, when we compare the Atlantic Basin hurricane numbers over the 15-year period from 1990-2004 with an earlier 15-year period (1950-64), we see no differences in hurricane frequency and intensity even though the global surface temperatures were cooler and there was a general global cooling during 1950-64 as compared with global warming during 1990-2004,” Gray and Klotzbach said.
