U.S. Violent Tornadoes Relative to the Position of the 850 mb Jet

The Violent Tornado Webpage from the Storm Prediction Center has been used to obtain data for 182 events in which a violent tornado (F4-F5 or EF4-EF5) occurred in the United States from 1950 to 2014. The position of each violent tornado was recorded on a circle plot compared to the low-level jet center for each three hour period. The position of each 850 mb jet was determined using the North American Regional Reanalysis (NARR) from 1979 to 2014 and NCEP/NCAR Reanalysis from 1950 to 1978. Plots are shown of the position of each violent tornado relative to the center of the 850 mb low-level jet. The United States was divided into four parts and the plots are available for the southern Plains, northern Plains, northeastern U.S. and southeastern U.S with a division between east and west at the Mississippi River. Great Plains violent tornadoes clustered around a center about 130 statute miles to the left and slightly ahead of the low-level jet center while eastern U.S. cases were oriented along the axis of the low-level jet and just ahead of the low-level jet center. Comparisons are made between the four regions and a plot is shown with 396 individual violent tornadoes mapped relative to the 850 mb jet.