Southwest winds that take hold this afternoon are to boost thermometer readings. The problem is winds effectively cancel temperature increases by lowering wind chills. The breezes -- 30 m.p.h. at times by late Tuesday -- are likely to all but eliminate the normal overnight decline of temperatures. But, the cold air these winds attempt to displace is denser than the mild air they carry. This forces much of the warmer air up and over the cool air mass. Initially only mid- and high-level clouds are to result from this process. But as Gulf and Pacific moisture reaches the area Wednesday, clouds thicken and ice pellets (sleet) or a sleet-rain mixture will develop, possibly transitioning to snow late Wednesday. There's enough moisture to suggest slippery travel conditions may develop.
A succession of precipitation-producing systems the next 2 weeks, each followed by cold air, is producing generous computer snowfall estimates ranging from 9 inches to as much as 21 inches over the period.
STORM COULD HAVE BEEN WORSE HERE
Had more of Sunday's copious liquid precipitation fallen as snow, Chicago could have been buried by 7 to 11 inches of snow.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune
