Thunderstorms will impact travel on the road and in the air across much of the midwestern United States on Wednesday before shifting to the central Plains and mid-Mississippi Valley on Thursday.
A warm, humid air mass in place will set the stage for robust thunderstorms to initiate into late week.
Cities at risk for a severe thunderstorm on Wednesday include Madison and Milwaukee, Wisconsin; Des Moines and Omaha, Nebraska; Springfield and Chicago, Illinois; Fort Wayne and Gary, Indiana; Grand Rapids, Michigan; St. Louis and Kansas City, Missouri; and Topeka, Kansas.
"Thunderstorms can produce conditions ranging from poor visibility to strong turbulence and sudden wind shear," AccuWeather Senior Meteorologist Alex Sosnowski said. "Arriving flights may be more spaced out or even suspended during such conditions."
Thunderstorms will be at their peak intensity during the late-afternoon and evening hours with the chance for damaging wind gusts and flash flooding before becoming more of a flood threat during the overnight.
"The timing of these thunderstorms will be bad for Milwaukee, Chicago and Kansas City, as these will likely arrive during the evening commute," AccuWeather Meteorologist Michael Doll said.
Wind gusts could be strong enough to snap trees and knock down power lines, resulting in sporadic power outages.
Where thunderstorms repeat an increased risk for flash flooding will exist. Never drive through a flooded roadway. Instead, turn around and find an alternate route.
"One to 2 inches of rain can fall from these storms in a short period of time and flood roadways," Doll said.
Anyone caught outside during a thunderstorm should seek shelter at the first rumble of thunder.
As drier, less humid air builds across the Midwest during the end of the week, the severe weather threat will shift southward on Thursday.
"On Thursday, the most intense thunderstorms will develop and move across the southern Plains and middle Mississippi Valley," Doll said.
While the coverage of the severe weather will not be as large as on Wednesday, any thunderstorm that develops could pack a punch.
Those from Wichita, Kansas, and Oklahoma City to Bowling Green, Kentucky, and Nashville should be on alert for rapidly changing weather conditions.
Conditions will improve by the weekend before dry, hot weather dominates next week.