ACCUWEATHER GLOBAL WEATHER CENTER —
AccuWeather.com reports persistent cold air during the first part of the spring is likely to cause severe weather to get off to a sluggish start in a heavily populated part of the nation. However, a marked turnaround is expected later in the spring for 2014.
On average, severe weather gradually ramps up moving forward through the spring. This year, the transition may occur later and may be more dramatic.
A spike in damaging thunderstorms, including some capable of producing tornadoes, is expected during May and June.
Early Season Temperature Extremes
According to AccuWeather Long Range Weather Expert Paul Pastelok, “We expect a southward dip in steering-level winds to occur much of the time over a large part of the Midwest to the Eastern states during March and the first part of April.”
This dip of strong winds high in the atmosphere, known as a jet stream trough, will generally keep warm, moist air at bay from near the Mississippi River to the Atlantic coast.
Last year, a similar setup occurred in much of the same area during the spring and led to a much lower-than-average severe weather season for the nation as a whole.
Thunderstorms are fueled by rising warm, moist air. As a general rule, the lower the temperature near the ground, the lower the risk for tornadoes and violent thunderstorms.
“This year, the ground is colder, the Great Lakes have an extensive amount of ice and the Gulf of Mexico waters are starting off colder than average,” Pastelok said. “All of these can have a negative impact on temperatures in the lower atmosphere.”
Over much of the Southeast, Midwest and Northeast, the tornado risk will be lower than average early on due to the colder-than-average environment expected.
According to Severe Weather Expert Dan Kottlowski, “As a positive note, we may not see the frequency and violence of severe thunderstorms and tornadoes that typically occur during March and much of April, because of the lingering chill impacting a significant part of the nation.”