CHICAGO (CBS) — Two waves of thunderstorms are expected to move through the Chicago area Sunday. 

The first wave arrives in the 7 a.m. hour along Interstate 39 and drives eastward to the city by 11 a.m. and then to Northwest Indiana. 

Tracking the storm

ROUND 1: 7 A.M. TO 1 P.M. 

How the atmosphere recovers from the morning activity will determine the strength of the second round. 

ROUND 2: 4 P.M. TO 10 P.M. 

The Storm Prediction Center has Chicago at a Level 2 out of 5 for severe storms. 

Damaging winds, large hail, and isolated tornadoes are possible with any storms that strengthen to severe levels. 

Forecast

SUNDAY: Gusty thunderstorms, some severe. HIGH: 74

SUNDAY NIGHT: Evening storms. Leftover showers. LOW: 58

MEMORIAL DAY: Shower chance. HIGH: 73