Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
Reged:
Posts: 2565
Loc: Melbourne, FL
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It is beginning to look like the era of 'high spin cycle' tropical cyclone activity in the Atlantic basin that started in 1995 has run its course with only three named storms recorded through the end of August. There were hints of that demise last year with a below normal level of hurricane development, i.e., only two Cat I storms - the last time that the Atlantic only had two hurricanes in a season was 1982. The last time that a season had three or less named storms by August 31st was in 1994 - the last year of the previous 'quiet cycle' in the Atlantic.
In the 45 seasons from 1950-2014 there were 17 seasons that only had three named storms by August 31st, so its not an unusual event, but it is unusual that the last one was 20 years ago. At the other end of the activity spectrum, in 1995, 2005, 2011 and 2012 there were 12 named storms by August 31st. Here are the previous 16 seasons since 1950 with three or less named storms prior to September 1st along with activity totals for those years, totals for the following year, and hurricane landfall statistics for the 16 seasons:
Year - # by 8/31 - total activity - following year - U.S. landfalls - FL landfalls
1952 2 6/6/3 13/6/4 1 0
1956 3 8/4/2 7/3/2 1 1
1957 2 7/3/2 10/7/5 1 0
1961 1 11/8/7 5/3/1 2 0
1962 2 5/3/1 9/7/2 0 0
1963 2 9/7/2 12/6/6 1 0
1965 3 6/4/1 11/7/3 1 0
1967 1 8/6/1 8/4/0 1 0
1977 1 6/5/1 12/5/2 1 0
1980 3 11/9/2 12/7/3 1 0
1982 3 6/2/1 4/3/1 0 0
1983 2 4/3/1 13/5/1 1 0
1987 3 7/3/1 11/5/3 1 1
1991 2 8/4/2 7/4/1 1 0
1992 2 7/4/1 7/3/1 1 1
1994 3 7/3/0 19/11/5* 0 0
Average 2 7/5/2 9/5/2 1 0
(*1995 was not included in the 'following year' average since 1995 was the start of the active cycle.)
Note that although these were all slow starting years (and mostly quiet years), every season except 1994 had at least one major hurricane. Although these were mostly quiet years, only three of them did not have a U.S. landfalling hurricane, while in Florida only three seasons had a landfalling hurricane. In the following year, one season had normal activity while seven seasons were above normal and seven seasons had below normal named storm activity, i.e., no correlation to the previous year. On average, based on the 16 seasons that started with three named storms (or less) by August 31st, this season would be expected to have four more named storms - with a minimum of one more and a maximum of eight more.
Since the lack of activity cannot be blamed on an El Nino event (it has not yet started), it is increasingly likely that the period of Atlantic high tropical cyclone activity has ended. However, it is important to remember that the likelihood of a U.S. hurricane landfall is about the same (approximately 22%) during a 'quiet cycle' era as it is during an 'active cycle' era - and that is also true for a Florida hurricane landfall (about 5%).
ED
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