donsutherland1
09-05-2004, 08:58 PM
Given Ivan's rapid intensification, one cannot rule out the possibility that Ivan could grow to a Category 5 storm, even if just briefly. In the historical context, it is unusual but not rare for a season to have a Category 4 and Category 5 storm develop.
Since 1950, there have been 12 seasons (22%) in which at least one Category 4 and one Category 5 hurricane developed:
1950
1951
1955
1957
1958
1961
1964
1979
1988
1989
1998
2003
In eight of those seasons, at least one major hurricane made a U.S. landfall:
1950
1955
1957
1958
1961
1964
1979
1989
In three of those seasons, a Category 4 hurricane made a U.S. landfall:
1957
1961
1989
It should be noted that in none of the years in which two or more major hurricanes made U.S. landfall were any of those landfalling hurricanes Category 5 storms at the time of landfall.
Also, in 9/12 (75%) of years with at least one Category 4 and one Category 5 storm, September saw 4 or more named storms. The lowest figure was 2 (1950, 1979, 1980). The highest was 6 (1961, 1988, 1998). The average was 4.2 September storms.
9/12 (75%) of years with at least one Category 4 and one Category 5 hurricane, also experienced 3 or more hurricanes in September. The lowest figure was 1 (1989). The highest figure was 5 (1955 and 1961). The average figure was 3.1 September hurricanes.
8/12 (67%) of seasons with at least one Category 4 and one Category 5 hurricane, experienced 2 or more major hurricanes in September. The lowest figure was none (1979). The highest figure was 5 (1961). The average figure was 2.0 major hurricanes in September.
In addition, all the above seasons saw at least tropical storm or hurricane develop after October 1. In 1979, a subtropical storm developed into a Category 1 hurricane in late October.
Since 1950, there have been 12 seasons (22%) in which at least one Category 4 and one Category 5 hurricane developed:
1950
1951
1955
1957
1958
1961
1964
1979
1988
1989
1998
2003
In eight of those seasons, at least one major hurricane made a U.S. landfall:
1950
1955
1957
1958
1961
1964
1979
1989
In three of those seasons, a Category 4 hurricane made a U.S. landfall:
1957
1961
1989
It should be noted that in none of the years in which two or more major hurricanes made U.S. landfall were any of those landfalling hurricanes Category 5 storms at the time of landfall.
Also, in 9/12 (75%) of years with at least one Category 4 and one Category 5 storm, September saw 4 or more named storms. The lowest figure was 2 (1950, 1979, 1980). The highest was 6 (1961, 1988, 1998). The average was 4.2 September storms.
9/12 (75%) of years with at least one Category 4 and one Category 5 hurricane, also experienced 3 or more hurricanes in September. The lowest figure was 1 (1989). The highest figure was 5 (1955 and 1961). The average figure was 3.1 September hurricanes.
8/12 (67%) of seasons with at least one Category 4 and one Category 5 hurricane, experienced 2 or more major hurricanes in September. The lowest figure was none (1979). The highest figure was 5 (1961). The average figure was 2.0 major hurricanes in September.
In addition, all the above seasons saw at least tropical storm or hurricane develop after October 1. In 1979, a subtropical storm developed into a Category 1 hurricane in late October.