Risk of severe thunderstorms across the Chicago area Sunday primarily along and south of the Interstate-80 corridor
Update 1PM CDT…
Indications are that the severe thunderstorm risk area Sunday will be centered a little farther south into central Illinois with the Chicago area, primarily along and south of Interstate-80 under a Slight to Enhanced Risk and the city of Chicago now outlooked in a Marginal Risk (see highlighted severe weather risk map).
The National Storm Prediction Center continues to outlook a good portion of the Chicago area for a Risk of severe thunderstorms Sunday. The greatest risk looks to be along and south of the Interstate-80 corridor, where an Enhanced Risk is depicted on the highlighted Severe Thunderstorm Risk Map. The Enhanced area covering central Illinois into northern and central Indiana (tan-shaded area on the map depicting a 30% chance of severe storms within 25 miles of a given location), covers a good portion of the Chicago area along and south of Interstate-80. The narrow Slight Risk (yellow-shaded depicting a 15% chance of severe storms within 25 miles of a given location) includes at least the southern portion of Chicago itself with the Marginal Risk dark-green-shaded area (5% chance of severe storms within 25 miles of a given location) farther north.
Sunday a warm front will be slowly moving north out of central Illinois with low pressure and a cold front approaching from the west, moving through northern Illinois into northwest Indiana during the afternoon. A wide band of showers and thunderstorms should develop over our area Sunday with the strongest activity during the afternoon into the early evening hours, as these frontal system and low pressure combine to produce strong to severe storms. Damaging winds and large hail will be the primary threats, although some localized flooding due to heavy rainfall could occur where training of storms ( thunderstorms repeatedly redeveloping and passing over the same general area) is observed. A few tornadoes may be possible, with the greatest risk south and east of Chicago.
The storm system should be east of our area by early evening, moving over Indiana into western Ohio.