By Wally Kennedy
The coldest winter in 30 years has cooled the prospect for tornadic weather this spring.
So far, this year’s frequency of severe storms capable of producing tornadoes has been way off the mark in terms of the national average.
“It’s been slow on the tornado front since the beginning of the year,” said Greg Carbin, warning coordination meteorologist with the national Storm Prediction Center in Norman, Okla.
“By this time of the year, we should be at 180 tornadoes nationwide,” he said in a phone interview. “We’re a hundred shy of normal. Of course, we’re entering the phase where we can expect to see an uptick at any time in severe weather activity.”
Carbin said variability in the amount of severe weather in January through March is not unusual.
“It’s a relatively quiet time, but some years can be really bad,” he said. “It’s tough to make any calls that relate the current facts with any kind of trend into the future. You can bet that things will pick up in April, May and June.”
The slow spell for tornadoes was preceded by a tornado drought in November that lasted for 23 days. During that month, the Storm Prediction Center issued no tornado or severe-thunderstorm watches. It was the only November since 1970 when no watches were issued during the month.
Carbin said there is some indication that the colder-than-normal winter and the El Nino effect, the warming of waters in the tropical region of the Pacific Ocean, could be affecting the weather.
“El Nino appears to be suppressing the number of severe storm events, so far,” he said. “Right now, we should be seeing more tornadic activity down on the Gulf Coast of Florida than we have been.”
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.
“It has a lot to do with the weather pattern we have been stuck in,” said Gene Hatch, climate specialist with the weather service station in Springfield. “We have been experiencing that since last July. It’s a semi-permanent pattern in which a ridge develops over the western United States, and that creates a trough for cold Canadian air to spill into the Midwest.
“It’s not a conducive pattern for significant severe weather.”
Hatch said the 30-day forecast from the Climate Prediction Center calls for a slight shift to above-normal rainfall and below-normal temperatures in April.
Last winter was a bit rough on Joplin’s severe-weather sirens. Tests this spring showed that three sirens had bad batteries, one had a blown fuse and one had a bad wire. Joplin controls 22 sirens within the city, two in Airport Drive and one in Duquesne, according to Keith Stammer, Joplin’s director of emergency management.