Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
343 AM EDT Tue Oct 18 2022

Valid 12Z Tue Oct 18 2022 - 12Z Fri Oct 21 2022


Days 1-3...
...Great Lakes to the central Appalachians...
While the threat for additional heavy snow accumulations is
expected to wane, deep cyclonic flow afforded by a slow-moving,
closed low centered over the eastern Lakes will continue to
support lake effect showers, with additional light accumulations
likely across portions of the region through Wednesday.  This
includes Upper Michigan and the northern Allegheny Plateau into
the central Appalachians.  WPC PWPF indicates that additional
accumulations are likely to remain under 4 inches for most areas. 
This includes areas southeast of Lake Michigan, where despite
steep lapse rates and deep northerly flow supporting intense
banding, a warm boundary layer is expected to result in mostly
rain.  By early Thursday, precipitation is expected to diminish
across the region as the upper low lifts out to the north and a
shortwave ridge moves across the Lakes.

The probability of significant icing is less than 10 percent.

Pereira