This ninth weekend of meteorological autumn is to end up the season's chilliest to date -- 22 degrees below last weekend's temperatures which included an unseasonable late-season 80 degree Sunday high. Northerly winds -- in effect a 3,000-mile atmospheric conveyor belt extending from the northernmost tip of Hudson Bay south to Mexico's Yucatan Peninsula -- are encouraging chilly air to spill southward off northern Canada's growing snowpack into the U.S. A mammoth Canadian high pressure is behind the gusty 20 m.p.h.-plus north winds raking Chicago and much of the Midwest and is expected to import enough dry air Saturday afternoon that the area's sprinkly morning cloud deck should break.
The incoming chill set new low temperature records in the Pacific Northwest Friday in Seattle (35 degrees) and Pendleton, Ore. (22 degrees).
Though cool in Chicago Saturday, city residents shivered even more a year ago when the high only reached 45 degrees.
--By Tom Skilling, WGN-TV Chief Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
