Does A La Nina Winter Portend A More Active Severe Weather Season In Minnesota?

It’s been a mild winter in Minnesota with the exception of an extended February cold wave. The state is under the influence of a La Nina which typically means a colder and stormier winter season but that is not always the case.

Climatologist Kenny Blumenfeld says a La Nina event is sometimes a sign of a more active severe weather pattern during the spring. A measurement of La Nina conditions is prompting some experts to suspect that the months ahead may be stormier than usual, as the index known as the El Nino/Southern Oscillation (ENSO) is showing similarities to the winter of 2010-2011 which preceded an unusually active severe weather season.

But Blumenfeld says there are some significant differences between then and now.

“I look at that (the ENSO index) and say well, meteorologically, we’re in kind of two different conditions. I don’t see a huge comparison between what we saw in 2011 and what we see now other than the fact that the ENSO Index that we use to measure the strength of these events was at about the same magnitude that it is now,” says Blumenfeld.

Blumenfeld says the La Nina of 2010-2011 produced winter conditions that were more severe than what we have experienced so far this winter.

Even so, the weeks ahead bear watching, according to Blumenfeld, who looked at data from other years when the severe weather season was preceded by a La Nina winter.

Blumenfeld says his research indicates that a La Nina spring can go either way with regard to severe weather.

One thing did stand out as Blumenfeld combed through the climatological records: a number of La Nina years were associated with at least one killer tornado event in Minnesota even if the severe weather season in general was not unusually active.

Blumenfeld says that the occurrences of deadly tornadoes during La Nina years may have been coincidental and he cautions that “there’s no smoking gun.”

Blumenfeld and co-host Jim du Bois also discuss the pre-drought conditions that are impacting much of the state and the prospects for precipitation on Wednesday.