GP2K Tropical Storm Figures

Number of Tropical Cyclones per 100 Years

The official hurricane season for the Atlantic Basin (the Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico) is from 1 June to 30 November. As seen in the graph above, the peak of the season is from mid-August to late October. However, deadly hurricanes can occur anytime in the hurricane season.

(Cited source: http://hurricanes.noaa.gov/prepare/season.htm,
downloaded from http://www.nhc.noaa.gov/pastprofile.shtml, on Sept 1, 2009.)

Selected excerpts from: "A Climatology Of Intense (Or Major) Atlantic Hurricanes"

Intraseasonal Variation of Tropical Storm Activity by Intensity
Level Expressed in Total Number of 6-Hour Occurrences for Each Day

The figure gives a more quantitative comparison of the annual cycles for various categories of tropical cyclones. This figure shows the daily incidence of tropical storms (maximum sustained wind speed greater than 17 m s-1 but less than 33 m s-1), minor hurricanes (Saffir-Simpson categories 1 and 2), and IH. The total incidence of IH is much less than that of minor hurricanes and tropical storms.

Normalized as Percent of Total Annual Activity Per Day

Although this figure indicates that the three categories peak at about the same time, it does not assess the relative strengths of the three maxima. Normalization by percent of annual activity per day accentuates differences in activity among the three groups, as shown in the figure. Intense hurricanes have a much sharper peak during the height of the season.

Sources:
FAQ : HURRICANES, TYPHOONS, AND TROPICAL CYCLONES -- FAQ Main Page,
By Christopher W. Landsea, Version 2.10, 09 August, 2000
http://www.aoml.noaa.gov/hrd/tcfaq/tcfaqHED.html

A CLIMATOLOGY OF INTENSE (OR MAJOR) ATLANTIC HURRICANES,
By: Christopher W. Landsea, Department of Atmospheric Science,
Colorado State University, Fort Collins, Colorado 80523
Monthly Weather Review, Vol.121, pg. 1703-1713, (1993)
http://www.aoml.noaa.gov/hrd/Landsea/climo/index.html