By Joseph D’Aleo, CCM

Although it is a week away, there are continuing signs we may be in for a typical early spring La Nina storm event that will threaten more flooding rains, at least one major tornado outbreak day and a major blizzard on the northwest side.  Flooding in La Nina years averages nearly $4.5 billion compared to an average of $2.4 billion. We have already seen examples of that this year in Missouri and Arkansas.

Major tornado outbreaks occurred in January 1999, a recent La Nina year, in Arkansas and Tennessee and in May in Oklahoma and Kansas with $2.3 billion in damages. And of course the super tornado outbreak of April 1974 with its 148 tornadoes that left 315 dead and 500 injured occurred during a very strong La Nina. In a prior La Nina event in 1965, the so-called Palm Sunday Outbreak had 78 tornadoes, 271 deaths and 1500 injuries.

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There were many F3-F5 storms in that 1974 Superoutbreak event (64).

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There were 38 F3-F5 tornadoes in 1965, the second most active day on record. See how the frequency of F3-F5 torndoes dropped off after the Great Pacific Climate Shift in 1977. In the cool Pacific PDO mode that preceded it, more La Ninas were favored and occurred and they frequently lead to more tornado outbreaks in the winter and spring along with more northern and western winter snows and spring flooding. We have already seen each of these occur in recent months. 

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We can only hope that it doesn’t come together and is not a major damaging event. If it does, with no sense of history, expect the media and friends to blame it on man-made global climate change.