Radar update: Isolated showers/storms beginning to develop

 

Instability has started to increase late Thursday afternoon following the thicker cloud cover and rain showers from the morning. This has allowed temperatures to warm into the low to mid 80s, but with dew points reaching the low 70s the heat index has reached the low 90s in a few locations.

Through the afternoon radar has been quiet locally, with only a few very isolated showers developing, but then quickly dissipating, over the last couple of hours. However, growing cumulus clouds ahead of a cold front over northwest Illinois have developed enough to allow a few isolated showers to show up on radar. Most of the thunderstorm activity, so far, has been further north - closer tied to actual low itself - in Wisconsin where a few flash flood warnings have been issued.

As the surface low dips further south into Wisconsin this evening, we will begin to see an increase in shower/storm activity, especially along and east of I-39. The risk for severe storms is low, but there is still a 'marginal risk' in place for an isolated severe storm or two through the evening. If storms do turn severe wind and hail would be our primary concern, followed by heavy rainfall.

The storm chance will come to an end late tonight as the low passes through the Stateline. Lingering cloud cover and scattered showers are likely to continue into Friday with gradual clearing taking place during the afternoon.