As our mild winter ebbs away and thoughts turn to daffodils, tulips and chirping songbirds, many weather-watchers are contemplating an annual question: How bad will our spring storm season be this year?
The answer depends on whom you ask.
Meteorologist Gary Lezak with KSHB is on the side of it being a wild severe weather season in Tornado Alley, which stretches from Texas up through Oklahoma, Kansas, Nebraska and Iowa. It also can extend into western Missouri.
“I think it’s going to be an active season for central and western Kansas,” Lezak said. “I also think there is a high flood potential for southern Missouri. They have already had flooding during the winter, and so when we go into the spring months, even in the next 10 days, they are going to start getting too much rain again.”
But researchers working on an experimental seasonal severe weather forecast for the United States think otherwise. Their overall forecast is for a relatively quieter year for the Plains and the Southeast.
“Our forecast is for below average conditions — so below average tornado and hail frequencies,” said John Allen, a post-doctoral research scientist with the International Research Institute for Climate and Society at Columbia University in Palisades, NY.
Allen is part of the team that created the seasonal outlook covering March, April and May, the historical peak of the tornado season.
“That doesn’t mean people shouldn’t be prepared for severe weather,” he said. “That is sort of the quandary. We can tell you about the upcoming season, but how are we supposed to tell you it’s going to be below average? Because it may be you get one event and your year was above average and it was a very bad year.”
People shouldn’t read too much into what a “below-average” year means, Allen said.
“It only takes one tornado to destroy a house or a neighborhood and take lives,” Allen said. “You look at some of the most deadly tornado events. They aren’t necessarily on a day with a lot of tornadoes.”
Severe storms in Tornado Alley typically are created when big low-pressure systems that formed over the Rockies draw warm moisture up from the Gulf of Mexico. That produces instability in the atmosphere. The changing of the winds can lead to the formation of tornadoes.
Part of the research Allen is working on looks at the relationship of severe storms during the spring months and El Niño events. There’s currently a strong El Niño event in the Pacific Ocean.
“What that typically leads to is a shift in the lows’ tracks,” Allen said. “The lows start to form further southward, down into southern Texas and down towards the Florida area. That means we see less moisture and less instability up over the Plains.”
He cautions there can be individual systems that draw the moisture northward and produce severe weather events.
“In general, when we have an El Niño condition, we generally see below-average severe weather activity,” Allen said.
When he says fewer tornadoes, that could mean 100 to 200 tornadoes below average over the entire U.S. On average, there are about 1,000 tornadoes that touch down per year.
“Naturally, 800 tornadoes still have a lot of potential to do a heck of a lot of damage,” Allen said.
Lezak said this El Niño has been one of the strongest we’ve had. Every year’s weather pattern is unique and this El Niño has brought some twists that weren’t anticipated, he added.
“This El Niño is going to be unlike any other El Niño,” Lezak said. “Already in the south, there have been an increased number of tornadoes. It’s a tough one to say because it’s already started pretty active down there and it will migrate farther west and north in the next few weeks.”
For the Kansas City area, Lezak is forecasting an above-average tornado watch season.
“In a typical year, Kansas and Oklahoma will have somewhere between five to 10 significant setups for possible severe weather — maybe 15 severe weather days,” he said. “Kansas City will usually see three or four setups.”
Lezak expects those setups to be significant this year for the risk of tornadoes.
“In the past years, there have only been a handful of tornado watches issued for our area,” he said. “It’s been really weird but this year I’m expecting a few more tornado watches than normal.”
He bases this on Lezak’s Recurring Cycle, a hypothesis that weather pattern is cycling and it sets up in October and November.
“The pattern we have been in for this entire season has set up in the fall and it continues now,” said Lezak, who also runs Weather2020. “The same pattern will continue through the spring and continues into the summer.”
This give hims an idea when severe weather is most likely. When it comes to the Kansas City area, however, Lezak said it’s a tougher forecast.
“We live in quite an interesting part of Tornado Alley,” Lezak said. “Kansas City is on the eastern edge.… There’s always a chance — we have had big tornadoes in the past.”
That includes the May 4, 2003, EF-4 tornado that touched down in Kansas City, Kan., crossed the Missouri River and caused damage in Gladstone and Liberty. One person died.
“That was a really big tornado,” Lezak said.
In 1957, the Ruskin Heights tornado cut a large path of death and destruction.
“Big tornadoes are very rare,” Lezak said. “Tornadoes in general are very small. There are people who live their entire lives here and never see a tornado.”
Lezak’s best advice is for people not to get complacent.
“We live in an area that could have a big tornado,” he said. “It may happen this spring or it may happen 100 years from now.
“My biggest suggestion would be to take every single one of the risks seriously and have a safety plan and go to that safe place when there’s a tornado risk. Tornadoes kill.”