[MARINE PARK]:::Too Quite....Where did all the storms go?

No. 133 Friday, August 27, 2010
The updated hurricane outlooks still forecast a very active Atlantic storm season -- about twice the “normal” level of activity.

   To mid-August, there have been only three named storms in the Atlantic, and this is about average. However, the other major hurricane “basins” in the Northern Hemisphere — the Eastern and Western Pacific — have also been quiet, and this is NOT normal. Usually, conditions that dampen storms in one region will make another boil over.
    In an average year, the three major basins would have a total of 21 named storms in the books by the middle of August. This year there have only been a dozen. The Western Pacific, usually by far the most active region, has seen only four named storms compared to an average of 11. According to NOAA researcher Gabe Vecchi, “the lack of tropical cyclones in the Northern Hemisphere so far this year is between a 1-in-80 and a 1-in-100-year event.”
    The main reason, according to the Weather Underground’s Dr. Jeff Masters, is not enough vertical instability. Normally, the sea surface is warm and the air at the top of the troposphere — the highest point of the earth’s atmosphere that thunder clouds can reach — is cold. The temperature difference — “vertical instability” — causes warm moist air to rise off the sea and condense into clouds. Bigger temperature differences make bigger clouds, that start to spill over when they hit really cold air.
    With sea surface temperatures at record levels in both the Atlantic and the Pacific, we should have plenty of vertical instability. However, around the end of June the upper atmosphere started to get warmer. By the end of July, in spite of warming seas, the temperature difference in the Caribbean, the tropical Atlantic and the Western Pacific had shrunk about 3°C, well below normal.
    Where did this hot, dry upper air come from? One possibility is the heat waves in the U.S. and central Europe this summer. The hot dry updrafts over land may have been pulled into the troposphere by corresponding downdrafts at sea. Another contributor may have been the unusual recent path of the Jet Stream, which has produced wild- fires and a killer heat wave in Russia, flood disaster in Pakistan and a hurricane off the Antarctic coast.
    These conditions can change as quickly as they appeared. The Moscow heat wave broke last week, and as we went to press Hurricane Danielle was gaining strength in the mid-Atlantic, with what may become Earl right behind her. The Eastern and Western Pacific also each had a new named storm.
    One forecast hasn’t changed much. Earlier this year, NOAAs Coral Reef Watch warned that Caribbean reefs were in danger of “widespread, severe” coral bleaching because of record high sea temperatures. The latest outlook report notes that the northern part of the region (including Jamaica’s north coast) got some temporary relief from Hurricanes Alex in June and Bonnie in July, but levels of thermal stress (bright sun and warm water) bounced back fast and are likely to go on rising through mid- October. Bleaching has already been reported from Puerto Rico.
    Healthy coral can survive brief periods of bleaching. For Jamaica’s reefs, struggling to recover from decades of abuse and neglect, getting the hurricane forecast back on track seems like their best hope.

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