Following up on his 2007 Atlantic hurricane season preview last week (see Daily GPI, March 28), AccuWeather.com Hurricane Center Chief Forecaster Joe Bastardi said Monday people should pay much more attention to the forecasted storm intensity than the much more publicized number of storms expected for a season. With that being the case, he warned that close attention should be paid to the 2007 season.
"The overall numbers are a red herring in the forecast for the amount of impact on the United States. If one looks at the '33-'38 seasons, the two most intense hurricanes in what is a very similar period in the AMO [Atlantic Multidecadal Oscillation], the early to midperiod of warming hit in relatively down years," he said. "In addition, there was no strong El Nino or La Nina signal in any of those years. The point is that the most legendary U.S. and Northeast hurricanes were the 1935 Labor Day Storm and the 1938 Long Island Express. The shift of the QBO [quasi-biennial oscillation] to westerly means the greater threat for stronger storms than last year." The QBO is a quasi-periodic oscillation of the equatorial zonal wind between easterlies and westerlies in the tropical stratosphere.
The 1935 Labor Day Storm rounded the west coast of the Florida Peninsula before impacting the Florida Panhandle, while the Long Island Express in 1938 traveled a due north trajectory before hitting western Connecticut and eastern New York.
"Looking at analogs and current patterns greatly impacts the upcoming hurricane season. The major disruptive and damaging hurricane threat area will be in the area that was damaged back in '04 and '05 across the Gulf," Bastardi added. "It's not the number of storms, but the intensity that will be the main concern. Since we are in the early stages of the AMO, the events of the late '30s [are] the basis of the upcoming hurricane forecast, but until spring is over, nothing can be specifically pinpointed on direct impact."
Bastardi said 2007 could display the intensity of 1935, but the number of storms could be equivalent to 1936. "Trying to determine what part of a three- to four-year cycle we are in is difficult to determine," he added. "1995-96 were big landfall years followed by a drought in 1997, only to pick up again in 1998-99. Perhaps, last year could have been that similar drought year."
The forecaster added that there is an increased threat in Florida/Gulf of Mexico. "With the exception of the western Gulf, which was jacked up because of the '54/'99 analogs, the Gulf forecast was hugely bearish for hurricane activity," Bastardi said. "The pure numbers I had were almost zero in the eastern Gulf and had to be adjusted up to get the forecast to where it was. It is not unlike the Gray Klotzbach [William Gray and Philip Klotzbach of the Colorado State University hurricane forecast team] adjustment up from the raw number to 17. In other words, the actual objective idea was on target and perhaps the shell-shock of the past couple of years contributed to what would have been a bold, perfect forecast (although you would have considered me mad as I simply said, 'no Gulf action at all,' and probably would have considered Bill and Phil underdone). But this year, I think major disruptive and damaging hurricanes are back into the areas that were damaged in '04 and '05. It is the intensity threat that scares me, not the number or overall storms at this time."
In addition to Florida and the Gulf of Mexico, Bastardi described New England as "fair game from now on until 2025," although he noted that the most frequent threats to the Northeast should be later in the run of the cycle. He said his statement last year that two major hurricanes would hit the Northeast within the next 10 years, sooner rather than later, still stands. "The summer temperature and hurricane pattern [last year] was so close to 1954 it can mean one of two things -- we were unlucky in '54 or lucky last year," he said. "Ernesto came on the exact date of Carol, but the track some 100 miles west of Carol up the East Coast spared what should have been a devastating hurricane. As it was, damage to the coastal areas north of Cape Hatteras was greater than Floyd. Florence was 250 miles east of Edna's path on the very same day as 1954. The number one target area last year, relative to averages, was the Canadian Maritimes."
Bastardi said the East Coast is open, but he does not at this time have the same kind of support he had for last year of shifting tracks east. "Since I believe we are in the early to middle stages of the AMO, the backdrop of the late '30s is the canvas on which the hurricane forecast is being painted, but it takes until spring is done for me to really hone in on where I think where impact is most likely."
The full AccuWeather.com hurricane season forecast will be available in early May, released in conjunction with the Second Annual AccuWeather Hurricane Summit in Houston. Gray and Klotzbach release their official 2007 Atlantic hurricane season forecast Tuesday.
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