The quiet beginning of the 2007 Atlantic Basin hurricane season is not expected to last.
All three of the most known tropical storm forecasting organisations for the Atlantic Basin have re-affirmed their pre-season predictions of an above-average season in terms of overall activity. However, the actual number of storms predicted is slightly lower than forecast before the hurricane season began on 1 June.
Fred Sambula, senior manager of the Cayman Islands Meteorological Services, said it would be a mistake to think Cayman would experience an inactive hurricane season because of the lack of activity so far.
‘We’re just beginning to enter the more active part of the hurricane season; August, September and October,’ he said, noting that the peak of the season wouldn’t come until the second week of September.
‘People must remember that Cayman has the highest rate of being impacted by hurricanes.’
According to the Hurricane City website (www.hurricanecity.com) Grand Cayman ranks first of a list of 152 Atlantic Basin cities and islands in being brushed or hit by hurricanes or tropical storms since 1871. Since that date, Grand Cayman has had 61 hurricanes or tropical storms come within 60 miles, which amounts to once every 2.23 years.
‘We’re in the thick of things when these systems are coming across the Atlantic,’ Mr. Sambula said. ‘We’re at risk during the hurricane season even when it appears less active.’
Because the waters in our area remain very warm late into the hurricane season, Mr. Sambula said Cayman remains at a high risk into October and early November.
‘The genesis areas for tropical development shifts to the western and south-western Caribbean Sea, where they can and start south of Cayman and move north,’ he said.
NOAA’s National Hurricane Center in the United States, which issued its August Atlantic Hurricane Season Outlook last Thursday, slightly lowered its pre-hurricane season forecast of named storms from 13-17 to 13-16; and the number of hurricanes from 7-10 to 7-9. Its forecast of 3-5 major hurricanes of Category 3 or above remained the same at 3-5.
On 6 August Britain’s Tropical Storm Risk reduced its pre-season forecast of 16.1 named storms, 8.9 hurricanes and 4 major hurricanes to 14.7 named storms; 7.8 hurricanes and 3.5 major hurricanes. All of the reduced numbers, however, are still higher than the average.
Colorado State scientists Phillip Klotzbach and William Gray also lowered their pre-season forecast slightly, from 17 to 15 named storms; from nine to eight hurricanes; and from five to four major hurricanes.
Klotzbach and Gray noted that sea surface temperatures in the tropical Atlantic Ocean have been kept lower because of Saharan dust blocking some sunlight from the ocean. Hurricanes thrive on warmer ocean temperatures, so the cooler seas tend to inhibit tropical storm development.
However, the recent emergence of a weak La Niña event in the Pacific Ocean, along with high sea surface temperatures in the Caribbean and Gulf of Mexico all point to an active remainder of the hurricane season, Klotzbach and Gray predicted.
The Atlantic hurricane season run through 30 November.
So far, the season has not seen a hurricane, although it did have Sub-tropical storm Andrea and Tropical Storms Barry and Chantal so far.
Computer models have forecast the emergence of two possible storms this week, on in the Caribbean and one that came off the coast of Africa last week.