ST. LOUIS (AP) — An unsettled weather pattern has five Midwestern states facing a moderate risk of severe storms on Tuesday.

The National Weather Service’s Storm Prediction Center in Norman, Oklahoma, warned Monday that portions of Nebraska, Kansas, Missouri, Iowa and Illinois are at a heightened risk of severe storms with hail, high winds and possibly tornadoes. The weather service says the tornadoes could be strong, if they occur.

Greg Carvin, lead forecaster for the Storm Prediction Center, says numerous thunderstorms will be fueled by warm, moist air in the upper Midwest.

Localized rainfall may not be too great because the storms will be so fast-moving, but Carvin says the risk of flash flooding exists.