Because spring is a transition season, cold to hot, Oklahoma often receives a little of both.
The astronomical spring begins with the vernal equinox at 6:02 a.m. CDT Wednesday in the Northern Hemisphere.
The spring equinox marks the time when the center of the sun sits directly over the equator, moving from south to north, said Wayne Harris-Wyrick, director of the Kirkpatrick Planetarium at Science Museum Oklahoma.
That multitasking feature of spring can mean big snows through March, major freeze events through early April and summerlike temperatures or spring storms throughout, said Gary McManus, Oklahoma Climatological Survey.
“Now, we all know that you can find these things in just about any season in Oklahoma,” McManus said, “but spring is particularly exciting for weather enthusiasts.”
Oklahoma had 58 tornadoes through April in 2012, and 51 in April 2011. In 2010, 90 twisters were recorded in May alone.
However, Freedom and Woodward reported 26 inches of snow associated with a late-March blizzard in 2009.
“Wheat growers and gardeners alike remember the big freeze events of 2007 and 2009 that caught tender plants unprepared,” McManus said.
With the jet stream still plunging down across Oklahoma at times in spring, before it retreats to the north for the summer, several primary ingredients necessary for exciting weather come together over the Plains.
The warm air from the south collides with cold air from the north.
“Throw in lots of moisture from a getting-warmer Gulf of Mexico, and you get an abundance of exuberant weather from Mother Nature,” he said.
Spring is important this year because of the ongoing drought situation. In general, Oklahoma has had two bad springs in a row as far as rainfall goes, McManus said.
That period from April through mid-June is the state's primary rainy season, and it's vitally important to recharge those soils and reservoirs before summer, he said.
The statewide average precipitation is 25.9 inches below normal since Oct. 1, 2010.
“Should we experience a third bad spring in a row,” McManus said, “another full year of drought becomes much more likely, as does the chance for another brutal summer like the last two.
“Spring is also our primary severe weather season, so we have to be mindful of that, of course.”