Warm-up brings a severe threat of flooding

The factors that contribute to wintertime river flooding in the Chicago area -- heavy
rainfall, surging temperatures, rapidly melting snow cover and ice-choked rivers -- are
falling into place.
The Chicago National Weather Service has issued a flash flood watch for metropolitan
Chicago from late Friday night through Saturday night, and advises that "major to record
flooding [is] expected this weekend." Computer models suggest that 1 to 3 inches of rain
will fall across the area by Sunday morning -- 1-inch totals most likely toward Rockford and
3-inch totals across southern sections and northwest Indiana.
A period of freezing rain, sleet and hazardously icy conditions is likely early Friday
before temperatures climb above freezing. Warming that continues into Saturday carries
temperatures into the 50s.
ACTIVE THUNDERSTORMS A POSSIBILITY
The interaction between 80-m.p.h. winds aloft and mild, moisture-laden, unstable air
drawn north from the Gulf of Mexico provides a favorable environment for thunderstorms.
--By Richard Koeneman, WGN Weather Center Meteorologist