As skies clear and winds diminish tonight, radiational cooling at ground level will present an excellent opportunity for widespread frost over much of northeast Illinois away from Lake Michigan early Tuesday morning.
Looking at the extended temperature outlook, this could be the last frost of spring 2005. The jet stream flow has been north to northwest for some time, opening the door to an almost continuous infusion of colder Canadian air masses. But a troughing pattern is setting up over the West Coast that will finally alter the flow aloft over the central Plains to more southerly by midweek. Computer models indicate that the newly established southwest flow at jet stream levels over the middle of the country the latter half of this week will persist through next week as well. What all this means for Chicago is a dry week ahead with significant warming, followed by a showery, warm and at times rather humid pattern the week of May 9-15.
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
