Update: All thunderstorms dissipated before reaching Arlington Heights.
A line of severe thunderstorms that formed over Interstate 80 is heading in a northeasterly direction, and should arrive in Arlington Heights by midnight if the thunderstorms continue to develop. At 10:00 a.m. the thunderstorms appeared to be dissipating as the passed northeasterly over Sandwich, Illinois.
The thunderstorm cells have slowed in their northeasterly path from 20 knots down to 12 knots. At 9:35 p.m the storms were about 45 miles southwest of Arlington Heights.
A second larger area of thunderstorms is behind the first line of storms. The second area of thunderstorms could hit around 2:00 a.m. unless they diminish as they travel east.