5A.1
Tornadoes in the United States as Related to the Tropical Pacific Sea Surface Temperature
Joseph T. Schaefer, NOAA/NWS/SPC, Norman, OK; and C. Marzban
Tornado frequency in several regions of the United States is correlated to the monthly mean sea surface temperature over four zones in the tropical Pacific Ocean. Within the assumptions set forth for the analysis, a weak but statistically significant correlation is found to exist between sea surface temperature in the Pacific Ocean and the number of tornados in various regions of the U.S. The strength and significance of the correlation depends on the coordinates over which the sea surface temperatures are assessed and the geographic region of the country. The strongest evidence found is for a negative correlation between the number of strong and violent (F2 and greater) tornados in an area that runs from Illinois to the Atlantic Coast, and Kentucky to Canada and the sea surface temperature in the central tropical Pacific. However even for this area, the correlation is too weak to be of prognostic value. This indicates that other factors play a dominant role in determining if tornadoes occur.
Session 5A, Climatological studies (Parallel with Session 5b)
Wednesday, 13 September 2000, 8:00 AM-10:00 AM
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