Tuesday, December 06, 2005

'Very Active' 2006 Storm Season Seen

"We foresee another very active Atlantic basin tropical cyclone season in 2006. However, we do not expect to see as many landfalling major hurricanes in the United States as we have experienced in 2004 and 2005. "
Professor Wiliam Gray's tropical forecast team at Colorado State University today issued its official annual December "extended forecast" for next year's tropical season, which starts June 1, 2006. Although it calls for fewer storms than in 2005, the bottom line still will not be welcome to coastal residents: "We expect Atlantic basin Net Tropical Cyclone (NTC) activity in 2006 to be about 195 percent of the long-term average."

The long range estimate of Gray's team is that next year we will see "about 9 hurricanes (average is 5.9), 17 named storms (average is 9.6), 85 named storm days (average is 49.1), 45 hurricane days (average is 24.5), 5 intense (Category 3-4-5) hurricanes (average is 2.3) and 13 intense hurricane days (average is 5.0)."

Gray's team hinted at today's predictions last month in its 2005 seasonal wrap-up report. Then, it was said:
Even though we expect to see the current active period of Atlantic major hurricane activity to continue for another 15-20 years, it is statistically unlikely that the coming 2006 and 2007 hurricane seasons, or the seasons which follow, will have the number of major hurricane US landfall events as we have seen in 2004-2005.
Predicted storm activity in 2006 for the East Coast, Gulf Coast, and Florida peninsula is summarized in a new chart the team prepared. It sees a 79% chance of a hurricane hitting the Gulf Coast, compared with a seasonal mean of 61% and a 47% chance it will be a Category 3 or worse hurricane, compared with a 30% historical mean.

The Colorado State tropical storm report candidly says its own 70% accuracy record in making December predictions for "various hurricane parameters" over the longer period of one-year is "rather modest." This is because it's "based on statistical schemes which, owing to their intrinsically probabilistic nature, will fail in some years."

The authors also acknowledge that while the sea surface has been warming over the last three decades, the recent increase in hurricane activity is more directly related to ocean salinity and a "multi-decadal" oscillation in the
strength of the Atlantic Ocean "thermohaline circulation."

'Multi-decadal oscillation' is a scientist's gentle way of saying to coastal residents 'this is normal, you idiots.' In fact, that's just about what Gray and his team do say:
Most Southeast coastal residents probably do not know how fortunate they had been in the prior 38-year period (1966-2003) leading up to 2004-2005 when there were only 17 major hurricanes (0.45/year) that crossed the U.S. coastline. In the prior 40-year period of 1926-1965, there were 36 major hurricanes (0.90/year or twice as many) that made U.S. landfall.
In a personal note, Prof. Gray also calls attention to the fact we have seen the last report issued under his name as primary author. He's moving on to even more desperate duties -- global warming:
Beginning with this forecast, the order of the authorship of these forecasts has been reversed from Gray and Klotzbach to Klotzbach and Gray. After 22 years (since 1984) of making these forecasts, it is appropriate that I step back and have Phil Klotzbach assume the primary responsibility for our project’s seasonal, monthly and landfall probability forecasts.

* * *
Phil is now devoting more time to the improvement of these forecasts than I am. I am now giving more of my efforts to the global warming issue and in synthesizing my projects’ many years of hurricane and typhoon studies.
The "Dr. Phil Klotzbach report" will take some getting used to.

With this announcement, weather watchers in Florida lose another familiar storm season sign-post. First, it was the sad death of "the old man" of The Weather Channel, John Hope, whose very presence on the TV screen served as a severe storm warning. Now "Dr. Gray" semi-retires from the hurricane predicting business.

Is there no end to these multi-decadal oscillations?

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