Slight Risk of severe thunderstorms Sunday night

Update 4:30PM CDT…

Most of the Chicago area remains in the Slight Risk for severe thunderstorms tonight (see headlined latest severe weather outlook above). The Excessive Rainfall outlook for the period ending at 7AM CDT Monday has been upgraded to Slight over the Chicago area tonight (map below).  Also the Chicago area is in the 70%-plus probability of thunderstorms within 12 miles of a given location from 11PM until 7M CDT (see red-shaded area on thunderstorm outlook map below).

Excessive Rainfall until 7AM CDT Monday…

Day 1 Excessive Rainfall Forecast

Thunderstorm Outlook map 1PM CDT to 7AM CDT Monday…

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The National Storm Prediction Center has outlooked the  Chicago area in a Slight Risk of Severe thunderstorms mainly Sunday night (yellow-shaded area on the highlighted map above depicting a 15% chance of severe storms within 25 miles of a given location). The main threat with these storms will be large hail, damaging winds and heavy downpours.

The saturated soils again leave us susceptible to localized flooding where heaviest rainfall occurs – so our area is in the Marginal possibility of Excessive Rainfall (green-shaded area on the map below).

The synoptic pattern has not changed appreciably with a stationary west-east-oriented frontal boundary from southern Iowa through central Illinois and Indiana. The southwest low-level jet flowing through Missouri into southeastern Iowa and western Illinois and overrunning the frontal boundary weakened this morning, but is expected to strengthen again Sunday night and combined with an upper-level impulse, trigger another Mesoscale Convective Complex of strong to severe storms that will spread into our area from the west overnight.

Excessive Rainfall outlook 7AM CDT Sunday to 7AM CDT Monday…

Day 1 Excessive Rainfall Forecast