Big Change on the Way Later in the Week

A ridge of high pressure lying across the area on Tuesday was responsible for sunny skies, warm temperatures, and light winds.  It's giving up a little of it's influence tonight as low pressure moves to the north along the Illinois/Indiana border.  High clouds are overspreading the area from the southeast, so the moon and stars will be visible through the clouds overnight. Temperatures will bottom out in the upper 40's tonight with light easterly winds.  On Wednesday the low will continue to move toward the north/northwest, and some scattered light showers could spread in from the southeast during the afternoon.  Once again high temperatures will be in the low 70's.  There could be a lingering light shower or sprinkle into evening  Clearing skies will develop after midnight, and it will be mild with a low in the low 50's.  On Thursday a strong cold front will approach from the west.  Temperatures are expected to reach near 70 degrees before the passage of the front by early afternoon.  There is limited moisture available for this system to process, so no drought relieving significant rains are expected.  There will be some showers, and possibly even some thunderstorms with the passage of the front.  The wind will shift to the northwest during the afternoon, and colder air will come pouring into northern Illinois from Canada and the northern plains.  Temperatures will fall back to near 60 degrees by late afternoon.  There could be some isolated showers lingering into the evening.  The temperature will continue to drop overnight, and the low around daybreak on Friday morning will be around 37 degrees.  It will be breezy and chilly on Friday with a high in the middle 50's.  The chilly weather will persist through the weekend.  There will be a little warmer weather early next week.