WHY NO HURRICANES?
September 7, 2001 So far the 2001 Atlantic hurricane season has seen no hurricanes. What's up with that, you may have asked? Answer: It's only the bottom of the fifth inning, and the Atlantic is known for its comebacks. Or, it's only the opening minutes of the third quarter.(Click NOAA satellite image for larger view of Hurricane Andrew taken August 23, 1992.)
Hurricane season goes from June 1st to November 30th. If you were to plot the start dates for all the tropical storms and hurricanesin the form of a frequency distributionyou would have a rather nifty-looking Bell curve. There would be little activity in June and July building toward a peak in August-September-October, according to NOAA's National Hurricane Center. The mid-point of the season is September 9th.
You can't really judge a seasonal forecast until the season is over. Most of those in the prognostication business, including the National Oceanic and Atmospheric Administration (Climate Prediction Center, National Hurricane Center and Hurricane Research Division) make a total season forecast, not one that is time-segmented.
The storms will come when they come. "Climatology" (the long historical record) shows that since 1944 there only have been three years1967, 1984 and 1988without a hurricane by the beginning of September. The year 1967 had no systems at all by August 29th but ended with eight named storms, seven of which became hurricanes. In 1984 the season ended with 12 named systems, five of which became hurricanes and one subtropical storm. And, 1988 ended with 12 named storms and five hurricanes, one of which was "Gilbert"one of only two Category 5 hurricanes (on the Saffir-Simpson Hurricane Scale) to strike the mainland.
While there have been no hurricanes so far this (2001) season, the Atlantic has experienced three tropical stormsBarry, Chantal and Deanhurricane wannabees, which reached wind speeds near 70 mpha whisker shy 4 mph of hurricane status). By the way, NOAA's intensity estimates are only good to within 5 to 10 mph. Each of these three tropical systems simply ran-out of timeand warm waterto intensify before coming ashore. "It's ironic that had they intensified we'd be talking about why we are above normal for hurricane activity this season. Climatology suggests that in an average year the Atlantic would have had two hurricanes by September 6th and three by September 10th," according to Max Mayfield, director of NOAA's National Hurricane Center.
Recall, too, that "mere" Tropical Storm Allison (and its remnant subtropical circulation) caused about $5 billion dollars in damage with 41 deaths directly related to the heavy rain, flooding, tornadoes and high surf. Tropical Storm Allison is the deadliest and most costly tropical/subtropical storm on record in the United States.
Each year similar questions pop-up. Folks were saying "where's the hurricane" in the late-starting 1992 season before Hurricane Andrew became part of the urban legend on August 24, 1992.
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