Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Posts: 2565
Loc: Melbourne, FL
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Update - 11 October
The arrival (and rapid departure) of heavily sheared Grace and Henri have increased the named storm total for the season to 8 - now the lowest total since 1997. These statistical additions have altered the dynamic with regard to an early close to the season - nothing remarkable about October 8th as the end of a season - but they do force another look into the 2010 possibilities.
With continued emphasis from NOAA for a continued moderate to strong El Nino over the upcoming winter, the seasonal outlook for 2010 seems to hinge on whether the forecasted event declines rapidly by April/May into June, or if it continues well into the 2010 summer - and that's a forecast that is far too early to make at this time. If El Nino persists, a 2010 seasonal outlook of 8/4/1 seems reasonable with 1973, 1993, 1968 and 1987 as the best analog years. If El Nino subsides in the late spring / early summer then a total for the upcoming season of 12/5/2 is more likely with 1978, 1988, 1966 and 1998 as the best analog years. The 'timing' of the return to neutral conditions will determine whether 2010 is a season of continued below normal activity or a return to normal or slightly above normal activity.
Original Post
The Gulf of Mexico and the Caribbean Sea are dry aloft. The southern subtropical jet stream is well established from the Gulf through the Caribbean Sea and extends eastward to western Africa. Windshear is moderate to strong in all of the Atlantic basin tropical cyclone genesis zones. Easterly waves over western Africa have diminished in magnitude. If the season is over, and it might indeed be, it would be the earliest end to the season (September 12th) ever recorded in the past 158 years.
In 1918 the season ended on September 14th, in 1855 and 1930 it was September 17th and in 1914 the only storm of that season ended on September 19th. There is still a chance for another hybrid subtropical type of system – but not much of a chance. There is a better chance that the next named system might not show up until next July. The current moderate El Nino is expected to strengthen during the winter, but it will probably slacken off considerably by early summer.
Nobody came close on the seasonal forecast totals for this year – even if another storm should increase the totals for the season. Everybody (myself included) was too high with their seasonal outlooks for named storms and hurricanes. With six named storms so far, this season in the quietest since 1986 in the Atlantic basin.
Its actually not too difficult to get an early hint into what the 2010 season might look like. If the El Nino drops off by early summer, the best analog years for SST anomaly would be 1966, 1958 and 1973 in that order – which would yield a more normal season with storm totals of 10/6/3 or 11/7/4.
ED
Edited by Ed Dunham (Sun Oct 11 2009 01:35 PM)
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