Notes:
Many more strong/violent tornadoes occur in the Southeast
U.S. during the cool season than in the Plains. Over 1200
strong/violent tornadoes have occurred in the last half century during
the November to March timeframe, versus about 400 in the Plains (and
more than half of these occurred in March). April sees slightly more
strong tornadoes in the Plains than the Southeast. Only in May and June
do the Plains strongly dominate in strong/violent tornadoes versus the
Southeast.