The National Weather Service has upgraded its risk of severe storms Thursday for virtually all of Arkansas.
The Storm Prediction Center had listed almost all of the state under a slight risk, which means scattered severe storms are possible. On Wednesday, the risk was upgraded by one rating to enhanced, which means numerous severe storms are possible.
Forecasters say the storms could pack damaging winds, large hail and tornadoes. Heavy rainfall is also expected.
Tabitha Clarke, a meteorologist with the weather service in North Little Rock, said the storms are expected to move through the state beginning Thursday afternoon and extending overnight into early Friday morning.
The enhanced risk level, which Clarke called the "upper end of slight," warns of more persistent or widespread storms.
Part of Northwest Arkansas, meanwhile, may see severe storms Wednesday night. Most of that region was under a slight risk for severe storms with only far Northwest Arkansas under an enhanced risk Wednesday night
EARLIER:
NORMAN, Okla. — Forecasters warned that the ingredients necessary to "blow up some big storms" would fall into place Wednesday and Thursday and cautioned millions of residents in the middle of the country — including Arkansas — to be aware of worsening weather.
Large hail, damaging winds and a number of tornadoes were possible Wednesday in the Southern Plains. Then the focus shifts to the mid-Mississippi River Valley, including virtually all of Illinois.
"Thursday will be the bigger day, but there's still potential [Wednesday] for significant storms in northeastern Oklahoma, eastern Kansas and perhaps into Missouri," said Greg Carbin, the warning coordination meteorologist for the Storm Prediction Center in Norman. "We're not exactly sure how things will evolve in that corridor."
In Arkansas, some storms were possible Wednesday morning in the northern part of the state. Part of Northwest Arkansas, meanwhile, was said to be under a slight risk for severe weather.
But Emilie Nipper, a meteorologist with the weather service in North Little Rock, said the "better chance" for severe storms will come Thursday afternoon and evening, when virtually the whole state is under a slight risk for severe weather.
"Damaging winds and large hail would be the primary threat with any severe storms," Nipper said in an email. "A tornado threat will also be present, given the strong winds near the surface."
The Arkansas storms could also pack heavy rain, Nipper said, with stronger storms dropping "as much as two inches or more in a short period of time." Heavier rainfall is expected across the southeast half of the state.
Forecasters in the region say heat, humidity, instability, an approaching front and the jet stream will all contribute to steadily worsening weather.
"By Thursday, it looks like all those ingredients come together. ... You can really blow up some big storms," Carbin said.
Areas that don't see strong storms Thursday could see heavy rain instead.
The Storm Prediction Center said Wednesday's storms in an area from Wichita, Kan., to Joplin, Mo., and on either side of the Kansas-Oklahoma border, could be significant — defined as having 2-inch hail, 75-mph winds and tornadoes rated at EF2 or higher.
Thursday, similar storms were predicted for an area from the Arkansas-Missouri border to southern Wisconsin, including Chicago and St. Louis.
The week was already off to a blustery start. Emergency officials said a tornado touched down briefly Tuesday night in southeastern Kansas, and hail and high winds caused problems from St. Louis to southwestern Indiana.
