Risk of strong to severe T-storms and localized flood-producing downpours tonight into Thursday

Strong to isolated severe thunderstorms are expected to develop to our west this Wednesday afternoon and spread east across northeast Illinois and northwest Indiana this evening and overnight tonight, ending from the west Thursday. The primary threat across the Chicago area will be localized flood-producing downpours and a few spots with damaging winds/hail. Timing of the storms reaching this area after peak-heating has the National Storm Prediction Center determining the area of greatest risk over the central plains, positioning our area mostly in the isolated Marginal Risk (dark-green-shaded area on the highlighted Wednesday-Wednesday night severe weather outlook map depicting a 5% chance of severe storms within 25 miles of a given location).

The National Weather Prediction Center has most of the Chicago area in the Marginal Risk of excessive rainfall, with the higher Slight Risk across our southernmost sections extending south and west into central and western Illinois and the heavy rain bulls-eye over southern Iowa and northern Missouri (see Wednesday/Wednesday night Excessive Rainfall Outlook map below).

A cold front is forecast to move southeast into northern Illinois later this evening with a center of low pressure rippling east along the frontal boundary, as it sags southeast tonight and Thursday. Conditions should improve from the west Thursday, as the low pressure tracks off to the east.

Wednesday/Wednesday night Excessive Rainfall Outlook map…

Day 1 Excessive Rainfall Forecast