For the next 48 to 72 hours Illinois into NW Indiana, including all of the Chicago area will be positioned in a broad area of moist unstable air extending from Texas northeast into the Great Lakes. Waves of strong storms generating flood-producing downpours will develop to our SW and track over our areas periodically along with the continued risk of severe storms. The Excessive Rainfall map for today and tonight is headlined with the severe weather outlook for the same time-frame below.
There will be scattered showers with a few embedded thunderstorms this morning with stronger thunderstorms likely later this afternoon and the overnight hours into Wednesday. With saturated soils due to recent rains, a persistent SW flow aloft, and an increasingly strong low-level southerly jet of warm moist air just above the ground, we will be in a prime position to receive copious amounts of rain, resulting in an increasing probability of localized as well as stream and river flooding in the coming 48 to 72 hours.