One benefit of a persistent winter in the East may be an unprecedented delay in the spring season of severe thunderstorms and tornadoes. The National Weather Service’s Storm Prediction Center in Norman, Okla., which began issuing alerts in 1970, has never gone through March without issuing any but that’s a possibility this month.
So far this year, the agency has issued just four tornado watches and no severe thunderstorm watches. A 51-day span between alerts earlier this year was the longest since 1986. And the preliminary tornado count so far this year – 28 – falls well short of the average seen by this date over the last decade – 193. UPDATED: A tornado touched down in eastern Oklahoma Wednesday, destroying dozens of mobile homes. At least one death was reported. The center also issued the first severe thunderstorm watch of the year.
In an SPC notice updated Monday, meteorologist Greg Carbin said there’s no single reason for the early quiet. March is typically when severe thunderstorms become common as warm, moist weather systems move north from the Gulf of Mexico and clash with colder air anywhere from the Great Plains to the Mid-Atlantic states. Certain conditions can spin tornadoes from those storm fronts. As a long, cold Eastern winter yields slowly to spring, that hasn’t happened much.
The quiet also means little for the season’s outlook, Carbin said. The busiest and quietest years for early-season tornadoes rarely wind up that way by season’s end.
In a broader analysis issued last year, Carbin found that the number of early-season watches has a weak relationship with the number of watches issued later in the season.
The heart of tornado season occurs in April and May. Plan ahead.