“We consider our Atlantic basin seasonal forecast for 2000 to have been a success,” said Professor Bill Gray, whose forecasting team predicted 11 storms, seven hurricanes, and three major hurricanes.
The forecast was also measured by the lifespan
of systems and this also showed an above average year. For example, he
predicted 60 named storm days and there were 66; he forecast 30 hurricane
days and there were 32; six intense hurricane days were expected and
there
were five. Though the numbers were not identical, Gray said the results
indicated that the Atlantic Basin had entered a new era of increased
hurricane activity. The cycle, which started in 1995, was expected to
run for about 30 years. But he cautioned climate change theorists not to
jump on the band wagon and use this cyclical activity as evidence of their
global warming theory.
“There is no scientifically
reasonable way that such an interpretation of this recent upward shift can
be made,” said Gray. “Anthropogenic greenhouse gas warming, even if
a physically valid hypothesis, is a very slow and gradual process that, at
best, might only be expected to bring about small changes in global
circulation over periods of 50 to 100 years and could not cause the abrupt
and dramatic upturn in hurricane activity as occurred between 1994 and
1995.”
Gray argues that the climate change theorists would have to explain
the downturn in hurricane activity between 1970 and 1994 when major hurricane
activity was down by 40 per cent compared to the 20 years before then and
the five years after. In addition, while activity in the Atlantic
Basin increased, cyclonic activity in the east and west North Pacific
Ocean declined.
The period 1995 to 2000 are the six most
active consecutive years recorded since 1886 with 79 storms, 49
hurricanes, and 23 major hurricanes. Hurricane Alberto was enigmatic. He
became the longest-lived August storm on record and in the 19 days as a
tropical storms, was the third longest-lasting storm on record for any
month. In addition, Alberto maintained his tropical characteristics in the
subtropical North Atlantic Ocean which was unusual, said
Gray.
The Colorado State University professor
cited special characteristics with this season which ends tomorrow. Among
them:
• An exceptional outbreak of tropical cyclone activity in September. Six formed during a 19-day period;
• No hurricane made landfall on the United States;
• No storms formed during June, July, or November;
• Seven storms formed in September making this only the fifth time so many systems formed in a single month;
• There was quite an enhancing high latitude hurricane activity in the central Atlantic, with six systems forming at high latitudes;
• Several storms which formed off the African coast and travelled westward did not develop into hurricanes which was not typical. Those weakening and dying at low latitudes were Chris, Debbie, Ernesto, and Joyce which apparently was due to a persistent strong Tropical Upper Tropospheric Trough (TUTT);
• Unusual strong influence of the Madden-Julian Oscillation which acts in a seesaw manner to enhance and then suppress cyclone formation on a monthly cycle. This could be seen with the clustering of cyclones. For example, four storms formed in a seven day period in August, six formed in a 19-day period in September and two within a three-day period in October. Gray’s prediction for 2001 is expected in a few weeks.