Research on La Nina, the opposite phase of El Nino, shows an increased tendency for severe weather in the Midwest in late winter and early spring.
“We certainly saw that in 2008, which was a La Nina year,” said Carbin.
A total of 2,194 tornadoes were logged in 2008, including the EF4 tornado that struck Picher, Okla., and central Newton County, killing 22 people. Normally, the nation logs between 1,200 to 1,300 tornadoes per year, causing 62 deaths and 1,500 injuries nationwide.
The connection to El Nino is not as strong, Carbin said. The existing El Nino has been in place since last summer. Now in a moderate phase, it is showing signs of losing its grasp. It should trend to neutral by this summer, Carbin said.
Steve Runnels, warning coordination meteorologist with the National Weather Service forecast office in Springfield, said: “We’ve had fewer severe-weather warnings this spring, largely due to the lack of low-level moisture. A series of cold fronts that dove southward into the Gulf of Mexico cooled its waters.
“When a storm approaches with southerly winds, there is a lack of warm, moist air to fuel the thunderstorms for severe weather to develop,” he said by phone. “Our severe weather has definitely been below normal.”
The only severe-weather event this year happened March 10, south of Joplin in McDonald and Newton counties. Five tornado warnings were associated with that storm.
“But all it takes is one event to turn it into the worst season ever for that one family who gets hits,” Runnels said. “We will get severe weather, tornadoes, hail and wind, and flash flooding this spring.”
Preliminary numbers rank this winter as the coldest since the severe winters of 1978-79 and 1979-80. Those ranked No. 1 and No. 2 in terms of cold.
This winter is the first since 1981-82 in which below-normal temperatures were reported in December, January and February, the primary months for cold weather in Missouri. The normal average daily temperature for December through January is 39 degrees. The average this winter was below freezing at 31.9 degrees.