Strong to Severe Storms Possible Tuesday Evening

The risk for strong to severe storms will increase for northern Illinois and southern Wisconsin during the late afternoon and evening Tuesday, bringing a threat for large hail, damaging winds and even isolated tornadoes. Skies will turn partly cloudy during the overnight Monday leading to locally dense fog through early Tuesday morning. Most of the fog should be out by mid-morning with skies turning partly cloudy into the early afternoon.

A few isolated showers will be possible during that time, but the storm threat is expected to ramp up between 3pm and 9pm Tuesday evening. Low pressure will strengthen as it moves from the Plains into Iowa Tuesday afternoon and then into southwest Wisconsin by Tuesday evening. The warm front associated with the low will lift very close to the Wisconsin/Illinois border during the late afternoon and evening. South of the warm front, temperatures will warm into the 70s as moisture

(dew points) increase. Depending on the evolution of storms to the west and how much sun we're able to see before the clouds move back in will determine just how strong storms will be locally.

The first storm activity could arrive as early as 2pm/3pm in northwest Illinois as an upper level disturbance moves in from the west. The second wave of thunderstorms will be likely with the arrival of the cold front between 6pm and 9pm. The greatest risks locally from any storms will be damaging winds, large hail and heavy downpours. However, storms that develop near the warm front could have a higher chance of rotating which may slightly increase the risk for isolated tornadoes.

The Storm Prediction Center does highlight much of northern Illinois and far southwest Wisconsin under a slight risk for strong to severe storms during the afternoon and evening. Make sure to stay updated with the forecast, especially if you're going to be out, and know where to go if severe weather does occur. Most of the thunderstorm activity should be done with by 10pm. Winds will then shift around to the north with a much cooler air mass moving in for Wednesday afternoon. A few wind-driven showers will be likely Wednesday with highs only reaching the mid to upper 50s.