A rare third consecutive November day of 70-degree temperatures is predicted
Wednesday. With a sharp change to colder weather predicted to begin Thursday night
and Friday, today's 71-degree high may well be 2008's final thermal excursion above
70 degrees, and Tuesday marked only the third time since 1872 that temperatures on
Election Day reached or exceeded 70 degrees. The vertical alignment of southerly winds
through a deep layer of the atmosphere -- from the jet stream down to ground level --
sets the stage for increasingly powerful winds to sweep the Chicago area. A powerful
autumn storm coming together in the Plains, responsible for a suite of winter weather
advisories across sections of 16 states, aids the developing high-wind regime here --
a windy setup that appears muscular enough to override the typical post-sunset
downturn in wind velocities Wednesday night. South exposure windows are likely to
rattle in 30+ m.p.h. gusts through the night into Thursday morning.
TEMP PLUNGES EXCEEDING40 DEGREES ARE NOT UNCOMMON AFTER
MULTI-DAY NOVEMBER 70-DEGREE SPELLS
A 43 degree temp drop is expected from Wednesday's high to Sunday night's low.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune
