Last Friday (30 November 2001) not only marked the end of November, but it also signaled the end of the official hurricane season in both the North Atlantic basin (which includes the Gulf of Mexico and the Caribbean) and the Eastern North Pacific basin, a region extending from the western coast line of North America westward to a longitude of 140 degrees west longitude. While a hurricane or other tropical cyclone may develop after 30 November, such an event is rare. In the North Atlantic, the latest recorded hurricane was on 31 December 1954 and the earliest was on 7 March 1908.
While the common perception is that the 2001 Atlantic hurricane season was relatively quiet since no hurricanes made landfall in the continental United States, this just-concluded season was relatively active as compared with the long-term average. As a preliminary review of the 2001 Atlantic hurricane season, 15 named tropical cyclones formed, representing either tropical storms or hurricanes - both types of systems are assigned a name, such as Michelle, for identification purposes. This total also includes an unnamed subtropical storm system that developed some tropical characteristics. Of these systems, 8 reached hurricane status, having winds in excess of 74 mph, while the other 7 reached only tropical storm status (with winds between 39 and 74 mph). Of the eight hurricanes, four were considered to be major hurricanes (category 3 or higher on the Saffir-Simpson scale).
The first tropical system of the season was Tropical Storm Allison that formed in the western Gulf off the Texas coast on 5 June 2001 and the last was Hurricane Olga, which formed on 24 November from a subtropical storm. and as of the time of this writing, continued as a tropical storm.
Three tropical storms (Allison, Barry and Gabrielle), made landfall along the coast of the continental United States. More details should appear this week at http://www.nhc.noaa.gov for more details.
In the eastern North Pacific, the hurricane season runs from 15 May to 30 November. The 2001 hurricane season had 15 named tropical systems, with 8 reaching hurricane status. Two of these hurricanes were major hurricanes. Adolph and Juliette both registering 125 mph sustained winds. Only Hurricane Juliette made landfall in Baja California at the beginning of October, after weakening to tropical storm force.
The 2001 hurricane season was more active than usual in the Atlantic Basin. Using long term averages running from 1931 to 1999, a typical North Atlantic hurricane season would have 10 named storms, with nearly 6 hurricanes and 4 tropical storms. The active 1995 season - one of the most active on record - had 19 named systems, with 11 being classified as hurricanes and 8 tropical storms. The least active in recent history was 1982 when only 5 named storms were reported.
Dr. William Gray from Colorado State University in Fort Collins has been issuing long-range hurricane forecasts for more than a decade. His forecasts are based upon several factors that include analysis of the wind field at several levels, the rainfall over West Africa and the effects of El Niño. In an April 2001 forecast (an update for one made in December 2000) he predicted 10 named storms, to include 6 hurricanes with 2 becoming major. He intends on issuing a forecast for the 2002 hurricane season later in December. For the forecast refer to http://typhoon.atmos.colostate.edu/forecasts/ .
The 2001 season in the eastern North Pacific was comparable to the long-term (1966-1999) average of 15 named tropical cyclones of which 9 typically reach hurricane status.
Return to the Monday Daily Summary
Return to DataStreme Homepage
URL: datastreme/learn/m_sup.html
Prepared by Edward J. Hopkins, Ph.D., email
hopkins@meteor.wisc.edu
© Copyright, 2001, The American Meteorological Society.