Severe weather is set to ramp up in May, meteorologists say, after blasts of arctic air kept the weather pattern quiet in April.
"The cold we've had in April has set us back from having a horrific year overall in the United States," AccuWeather Expert Long-Range Forecaster Paul Pastelok said.
"Even though we've had an active southern Plains year so far, it could've been worse."
February and March were unusually active with respect to tornadoes, but cold air through the first half of April has kept the atmosphere stable, preventing any widespread severe weather.
According to the Storm Prediction Center, preliminary tornado numbers* in April totaled only 20, compared to a three-year average of 129.
However, that could soon change as warmer weather arrives toward the end of the month.
"The upcoming warm weather pattern will be more conducive for severe weather than the pattern that dominated much of the first half of April," AccuWeather Meteorologist Brian Lada said.
"As systems move from the southwest U.S. and the Rockies into the Plains in the coming weeks, they will pull in more moisture from the Gulf of Mexico, a key ingredient for severe thunderstorms," Lada said.
These ingredients, combined with retreating cold air, will lead to an active month of May.
"There can be severe weather anywhere [during May]; it will be widespread and hard to pinpoint," Pastelok said.
A higher-than-normal number of tornadoes is forecast, with Oklahoma, Texas, Arkansas and Missouri likely to be the primary targets.
By June, as is typical climatologically, the threat will shift to include the northern Rockies, central Rockies, southwest Plains, central Plains and the lower to mid-Mississippi Valley.
"This area will be impacted by large hail and tornadoes with a higher chance for severe outbreaks," Pastelok said. "Denver to Kansas City to Dallas and Little Rock are all at risk."
The Rockies and western Plains will be more prone to severe outbreaks in July, with hail and strong wind gusts as the main threats. Denver, Colorado; Billings, Montana; and Cheyenne, Wyoming; should be on alert.
*Preliminary tornado numbers are typically higher than actual numbers due to duplicate reports of the same tornado.