Much of Arkansas is in the area of “greatest risk” for severe weather that may include a spike in tornadoes and damaging thunderstorms and is expected to begin in early Spring, according to AccuWeather.com.
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.
"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,” said AccuWeather Long Range Weather Expert Paul Pastelok.
The National Oceanographic & Atmospheric Administration estimates that about 1,300 tornadoes hit the U.S. every year. The federal agency shows 1,691 reported tornado events in 2011, 939 in 2012 and 908 in 2013. Tornado-related deaths totaled 553 in 2011, 70 in 2012 and 55 in 2013. April is the month with the most tornadoes, with a three-year average of 350. May is second with 238.
Between 1980 and 2009, there were 965 reported tornadoes in Arkansas, ranking the state 15th for the number of events, according to this NOAA report. Texas was first during the same period with 4,557 reported tornadoes, Kansas was second with 2,259, Florida was third with 1,913, Oklahoma was fourth with 1,647 and Nebraska rounded out the top five with 1,537.
However, Arkansas ranks fourth in the total number of deaths (126) in the same period. Alabama is first with 165, Texas had 147 reported deaths and Tennessee had 142. Arkansas ranks second in the number of “killer tornadoes” in the period with 47. Texas ranked first with 58.
JET STREAM INFLUENCE
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.
"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.
"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,” said Severe Weather Expert Dan Kottlowski.
Kottlowski urged caution when comparing overall numbers of tornado and other severe weather incidents to other seasons.
"This is not to say there cannot be a couple of outbreaks of severe weather during the first part of the spring in portions of the Midwest, the South and even the Northeast," Kottlowski said. "People should not let their guard down."
EARLY START FOR SEVERE WEATHER
There is one area where severe weather may get off to an early, typical start with the possibility of frequent severe weather events during March and April. In portions of Texas, Oklahoma, western Arkansas and western Louisiana, Kottlowski and Pastelok both expect warmth to build quickly relative to the balance of the Central and Eastern states.
"We expect a normal to perhaps an above-average amount of severe thunderstorms over the Central states during May and June," Kottlowski said.
Indications are that the jet stream will pull to the north during May and June and hence will allow warm, moist air to flow northward more regularly over the Midwest.
"While warmth combined with drier air may keep a lid on severe weather for a time in the East during May, the air should be thoroughly warm and moist over much of the Midwest and South Central states," Pastelok said.
Areas from the Dakotas and Minnesota to Wisconsin, Michigan, the Appalachians and Atlantic coast should experience surge of severe weather during June and July.
A significant number of severe weather events are likely to continue to occur over the balance of the Midwest and South Central states and expand to along the Rockies as spring draws to a close and summer begins.