Expects still stress alertness, as even small storms and tropical depressions can pack a big punch
The Colorado State University’s (CSU) forecast team announced today that it had revised its 2009 forecast for the Atlantic Basin Hurricane Season, down from 12 named storms, 6 hurricanes, and 2 major hurricanes forecasted in April, to 11 named storms, 5 hurricanes, and 2 major hurricanes.
A release from CSU said the forecasters, Drs. Phil Klotzbach and William Gray, “…today predicted a slightly below-average 2009 Atlantic basin season, based on a cooler-than-normal tropical Atlantic and the greater potential for a weak El Niño during the bulk of the hurricane season.”
“We believe that there is a slightly greater chance of a weak El Niño developing this summer/fall than there was in early April,” said William Gray, who has been doing the forecast for 26 years now.
“El Niño conditions would likely increase levels of vertical wind shear and decrease Atlantic hurricane activity,” Gray explained.
The CSU forecast says, “Currently observed climate factors are similar to conditions that occurred during 1959, 1960, 1965, 2001 and 2002 seasons. The average of these five seasons had slightly below-average activity.”
The National Ocean and Atmospheric Administration (NOAA) in the US had issued its season outlook on May 21, saying that they expect a near-normal season this year.
“Forecasters say there is a 70 percent chance of having 9 to 14 named storms, of which 4 to 7 could become hurricanes, including 1 to 3 major hurricanes (category 3, 4 or 5).
“Shaping this seasonal outlook is the possibility of competing climate factors. Supporting more activity this season are conditions associated with the ongoing high-activity era that began in 1995, which include enhanced rainfall over West Africa, warmer Atlantic waters and reduced wind shear. But activity could be reduced if El Niño develops in the equatorial Eastern Pacific this summer or if ocean temperatures in the eastern tropical Atlantic remain cooler than normal,” NOAA’s statement had said.
It noted also that, “Tropical systems acquire a name—the first for 2009 will be Ana—upon reaching tropical storm strength with sustained winds of at least 39 mph. Tropical storms become hurricanes when winds reach 74 mph, and become major hurricanes when winds increase to 111 mph. An average season has 11 named storms, including 6 hurricanes with 2 becoming major hurricanes.”
There are 5 categories on the Saffir-Simpson Hurricane Wind Scale: category 1: sustained winds of 74-95 mph; category 2: 96-110 mph; category 3: 111-130 mph; category 4: 131-155 mph; and category 5: greater than 155 mph.
Experts stress that even though tropical storm and hurricane activity this season—June to November—are not expected to be as high as last year’s, people in hurricane-prone areas such as Belize must continue to keep on the alert.