Showers and a few thunderstorms overnight and Monday forenoon – Marginal Risk of severe storms with large hail
At low-levels a moist southerly flow will prevail over northeast Illinois/northwest Indiana into southern Wisconsin ahead of a cold front approaching from the northwest. Along and in advance of the cold front convergence and convection combined with a strengthening southerly low-level jet will contribute to increasing instability, enhancing the probability of showers and thunderstorms. A few of the storms could become strong, possibly accompanied by large hail. Precipitation should end from the west as the front passes through our area between about 10AM and 2PM CDT Monday.
The National Storm Prediction Center continues to project a good portion of the Chicago area in the Marginal Risk area for severe storms at least until 7AM CDT Monday morning (dark-green-shaded area on the highlighted map, depicting a 5% chance of severe storms within 25 miles of a given location). There are some indications that most of the stronger storms could remain south of Interstate-80, but strong storms could hit in almost any part of our area until the threat passes later in the forenoon/early afternoon Monday. Individual showers/thunderstorms should be moving in a more east-southeast direction.
Current Metro Weather Radar Mosaic…