Friday, April 04, 2008

Weather Outlook: Wet/Stormy Spring

As the La Nina pattern continues to sustain itself well into the spring, an active southern storm track should continue bringing wetter than normal days throughout the Ohio Valley and midwest. Judging by the above normal frequency of tornadic weather since the first of the year,
this La Nina pattern could also be responsible for a greater frequency of severe weather.

So far in 2008, in the first three months, there have been 368 confirmed tornadoes, 181 above the average over the last three years.

List of Tornado Outbreaks Through April 4th

Flooding in La Nina years averages nearly $4.5 billion compared to an average of $2.4 billion. We've already seen examples of this with the flooding in Missouri and Arkansas.

Has a La Nina pattern been the culprit for severe weather outbreaks in the past? Absolutely.

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.

Does this mean that we are doomed and every severe weather event will be loaded with tornadoes. Certainly not. The atmospheric conditions present are just more condcive for tornadic development. I just hope as do all of us that this doesn't materialize.

1 comment:

The Lorax said...

And even as La Nina cools off... so to speak... the constant waves coming in on the Pacific jet remain relentless.

Asia-West Pac Satellite

The effects of a weakening La Nina may not be seen for many weeks to come.

Also worth noting: An above average hurricane season is indeed possible given the La Nina configuration. The Southeast may not need to worry about drought by the end of the Fall.

Finally, tornadic days increased for the OH valley in La Nina years... says FSU in a bootstrapped study.