Monday, February 21, 2005

Bermuda harbinger? My loyal reader may remember my 2004 Hurricane season in review post, in which I said "it is clear that if one could anticipate the upper level pattern in advance, then it would be reasonably straight-forwardt o make a decent forecast of the probability of  storms making landfall. "  An article in today's Palm Beach Post, Lurking storm blocker bad omen for season, is related to that thought: The subtropical ridge of high pressure became infamous in 2004 as one of the prime villains behind Florida's repeated pummeling. Strong and unusually close to the southeastern United States — at least by the standards of the past decade or so — the ridge squatted off the coast like a surly bouncer, barring hurricanes from sweeping north up the Atlantic. Instead, it shoved the storms toward Florida. Again, again, again and again. Guess what? The Bermuda High is still in roughly the same place, according to the National Weather Service. If the high lingers there through the summer and fall, Florida could be nature's punching bag for yet another hurricane season. Experts say it's too far soon to tell whether that dire scenario will occur. But it's not too soon to prepare for it. "If in fact the subtropical (Bermuda) High is going to be more frequently positioned farther south and west like it was in 2004, then one clearly has to be concerned," said James Elsner, a Florida State University hurricane researcher. Indeed, from this afternoon's Tropical Weather Discussion : STRONG SFC HIGH IS SLIDING SE OVER THE W ATLC WATERS NEAR BERMUDA AND THE ASSOCIATED SFC RIDGE IS BUILDING WWD OVER FL AND THE GULF...EXTENDING FROM ABOUT WEST PALM/FT. LAUDERDALE NWWD TO HOUSTON TX. The article continues Jim Lushine, a meteorologist for the weather service's Miami office, offered one hint to watch for: If May is unusually dry, as it was last year, that could be evidence that the high is still lingering — and an omen of bad things to come. "I'm not saying we'll have four hurricanes in one year," he said. Then again, "I wouldn't be shocked if we had six." Others cautioned that the high's behavior was just one of many weird occurrences in 2004, a year so off-the-wall bizarre that a hurricane hit Brazil — in March. (The storm, unofficially named Catarina, was the first hurricane in at least four decades in the South Atlantic.) The Earth's climate is so complex that scientists don't understand everything that goes into creating a vicious hurricane season. "You have to have so many conditions to be perfect" to see another season like last year's, said Brian Bossak, a researcher for the U.S. Geological Survey in St. Petersburg. "Even if one condition were conducive to a repeat, everything else might not be." The disconcerting thing is that if you look over the high activity hurricane years in Florida, you can't find a year in complete isolation, they come in pairs or groups. Examples?  Try 1928 / 1929, 1932 / 1933 / 1934, and 1964 / 1965.  Just forcasting by analog, one would have to be concerned for Florida again this season (especially the area from south of Palm Beach to Key West, which anomalously lucked out in 2004).  From a dynamic standpoint, my year in review post reported that there were currently no inhibiting factors to keep 2005 from being at least an average season in terms of activity.   At this moment, things are not looking good for Florida. The article references Dr. Gray's December forecast for the 2005 hurricane season.  Unfortunately,  forecasts so far out haven't shown much value.  Dr. Gray's next forecast is scheduled to be released on April 1 (seriously). Until then, keep an eye on the Atlantic Surface analysis! For those interested, here's a link to  James Elsner's website (FSU professor mentioned in the article). Weather comment []5:58:59 PM   trackback []