Chicagoans are accustomed to most of their fronts and weather systems arriving from
the west. But sometimes a "back door" cold front -- one which slides across the area
from the northeast -- visits the area. Tuesday is such an occasion. The front's passage
briefly checks the string of slow but steady daily temperature increases under way here
since Saturday. Strengthening northeast winds behind the front Tuesday will lower
temperatures over much of the area into the 70s. An isolated shower or thunderstorm
may develop in a few spots west and south of the city as the gusty northeast winds
converge with slower moving air. It's a setup that forces air to rise, cool and condense.
Noticeably muggy air won't be absent long. Resurging warmth and humidity as early as
Thursday afternoon threatens to ignite clusters of thunderstorms while boosting
temperatures late this week.
WINDY POST-FRONTAL TEMPERATURE DIVE TAKES GREEN BAY FROM YEAR'S FIRST 90 TO 75 DEGREES IN AN HOUR
Temps in Green Bay went into a tailspin Monday evening as the back-door front visiting
Chicago on Tuesday passed. Readings there fell from 90 degrees -- the first 90s there
in 2008 -- to 75 in an hour. Northeast winds gusted to 31 m.p.h.
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune
