The 2007 hurricane season got off to a busy start with the formation of Tropical Storm Andrea on May 9 — nearly a month before the official June 1 start of hurricane season.
Colorado State University’s Department of Atmospheric Science has forecast a very active Atlantic hurricane season for 2007, with a predicted 17 named storms, nine hurricanes and five intense hurricanes.
The report, compiled by Professor Emeritus of Atmospheric Science William Gray and research associates Philip Klotzbach and William Thorson, calls for an above-average risk of a major hurricane making landfall in the Caribbean.
Gray’s latest forecast, which came out on May 31, predicted an even more active season than Gray originally called for in his December 2006 report.
Forecast Increased Since December
“We have increased our forecast from our early December prediction due largely to the rapid dissipation of El Niño which has occurred over the past couple of months,” according to the report. “We expect either neutral or weak-to-moderate La Niña conditions to be present during the upcoming hurricane season. Tropical and North Atlantic sea surface temperatures remain well above their long-period averages.”
The National Oceanic and Atmospheric Association is also calling for an above normal hurricane season.
“The outlook calls for a very high likelihood of an above-normal hurricane season, with 13 to 17 named storms, seven to 10 hurricanes and three to five major hurricanes,” according to NOAA’s Web site. “The prediction for an above-normal 2007 hurricane season reflects the expected combination of two main climate factors — the continuation of conditions that have been conducive to above-normal Atlantic hurricane seasons since 1995, and the strong likelihood of ENSO (El Niño-Southern Oscillation)-neutral or La Niña conditions in the tropical Pacific Ocean.”
El Niño, La Niña
El Niño is a variation of the ocean-atmosphere system in the tropical Pacific, whose consequences are seen around the world.
“Among these consequences are increased rainfall across the southern tier of the U.S. and in Peru, which has caused destructive flooding, and drought in the West Pacific, sometimes associated with devastating brush fires in Australia,” according to NOAA.
While El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific, La Niña is characterized by unusually cold ocean temperatures.
While NOAA does not forecast the risk of hurricane landfall, the administration does note that hurricane strikes increase during hyperactive hurricane seasons.
“The historical probability for multiple hurricane strikes in the United States increases sharply for hyperactive seasons,” according to NOAA’s Web site. “For the U.S., all hyperactive seasons since 1950 have had at least one hurricane strike, 92 percent have had at least two hurricane strikes and 58 percent have had at least three hurricane strikes.”
Following a record 2005 hurricane season, with 28 named storms, 15 of which became hurricanes, 2006 did not meet Gray’s prediction of an active hurricane season.
“The 2006 Atlantic basin hurricane season had activity at slightly less than average levels,” according to Gray’s post-2006 hurricane season summary. “This activity was much less than predicted in our seasonal forecasts.”
Gray’s forecast at the beginning of the 2006 hurricane season, released May 31, 2006, called for 17 named storms and nine hurricanes, five of which were predicted to be intense.
There were just nine named storms in 2006, five of which became hurricanes. Just two became intense hurricanes.
Both Gray and NOAA will issue revised hurricane season predictions in August, the beginning of the August through October peak of hurricane season.
Names for this year’s storms are: Andrea, Barry, Chantal, Dean, Erin, Felix, Gabrielle, Humberto, Ingrid, Jerry, Karen, Lorenzo, Melissa, Noel, Olga, Pablo, Rebekah, Sebastien, Tanya, Van and Wendy.