Snowfall across 32 hours could be heaviest yet

This winter's 21st measurable snow is to be spread across 32 hours -- twice the length
of the city's most substantial previous snow this season -- and it arrives in at least two
distinct periods. Snow accumulates 1 to 3 inches in the first, enough to complicate
Friday morning's rush hour. But there are indications the snow band will shift north of the
city offering a break in snowfall, or at least a reduction to more occasional snowfall
this afternoon. But, the second wave of snowfall -- and this system's most substantial --
sweeps in later this evening and tonight and is likely to last into Saturday morning. At
that point northeast winds will have replaced Friday's southeast flow and the potential for
lake-enhanced snow showers (snow showers feeding off lake moisture) may take over into
early Saturday afternoon.
Our snowfall forecast -- 4 to 9 inches north of Interstate Highway 80, trending heavier
to the north and near the lake, and 1-3 inches with amounts trending lighter southa -- is
based on projections of 0.49 inches of water from the system which is to fluff into
about 6 inches of snow. The addition of 1-3 inches of lake snow finishes the tally.
HUGE NORTH/SOUTH TEMP SPREAD OF 85+ DEGREES IS FUELING STORM
--Tom Skilling, Chief Meteorologist, WGN-TV/Chicago Tribune