3.5
U.S. Tornadoes of 2009
Russell S. Schneider, NOAA/NWS/NCEP/SPC, Norman, OK ; and G. W. Carbin
The 2009 tornado year for the United States was characterized by a strong start, an unusual pause in May, and a return to active severe weather through the summer. The tornado season started with an unusually early Southern Plains outbreak on 10 February that included a violent EF4 tornado in Lone Grove, Oklahoma that caused 8 fatalities. This was closely followed by an EF3 tornado with 1 fatality in Sparta, Georgia on 18 February. A two-day severe weather outbreak across the mid section of the nation resulted in 5 fatalities on 9-10 April. This episode included an EF3 tornado striking Mena, Arkansas after dark and an EF4 tornado hitting Murfreesboro, Tennessee the following day. Widespread severe weather impacted the central U.S. during the first two weeks in May. This included derecho events with embedded tornadoes over the south on 3 May and across the Midwest on 8 May. There was a remarkably quiescent two week period beginning with the third week in May, that provided relief to many, but caused difficulties for the initial year of the VORTEX-2 field experiment. This unusual mid-to-late May break, during what is typically the height of the U.S. tornado season, resulted in no Convective Watches issued for the Unites States during the nine day period from May 17th-25th. The season resumed its ferocity in early June, but fortunately the storms resulted in no confirmed fatalities. A remarkable tornado in Wyoming was captured in great detail by VORTEX-2 scientists on 5 June. Another strong wind-producing derecho ravaged the southern U.S. from Kansas to Alabama on 12 June and a number of tornadoes produced substantial damage in the Memphis area on 30 July. These events gave way to a quiet tropical cyclone season with the lack of land falling tropical systems contributing to another period in the year exhibiting a low level of tornado activity from August to October. This slow spell was punctuated by a strong mid-latitude storm system that spawned several tornadoes on 9-10 October, including a killer tornado in Mississippi on the 10th. Forecasts for a strengthening El Nino event during the 2009-2010 cool-season heralds the potential for a stronger than average Southeast storm track, and the potential for enhanced Gulf Coast and Florida tornado activity into early 2010.
Session 3, 2009 US Weather Impacts
Tuesday, 19 January 2010, 3:30 PM-5:30 PM, B206
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