Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
344 AM EDT Sat Oct 15 2022

Valid 12Z Sat Oct 15 2022 - 12Z Tue Oct 18 2022

Day 1...

The probability of at least 4 inches of snow is less than 10
percent.

The probability of significant icing is less than 10 percent.

Days 2-3...
...Upper Great Lakes...
The first impactful lake effect snow event of the season appears
likely, with several inches of snow possible across portions of
the U.P. of Michigan.  An amplified pattern will persist across
North America through early next week.  The upper low currently
centered over the Upper Great Lakes is forecast to lift into
eastern Canada later today, however the broader scale pattern will
remain relatively unchanged as shortwave dives quickly south
across central Canada, with a new upper center developing over the
Upper Great Lakes Sunday night into early Monday.  The GFS
continues to show heights -2 to -3 sigma as a deep upper low
develops and drifts slowly east across the region on Monday and
Tuesday.  Deep northerly to northwesterly flow west of the low
will support 850 temps dropping to around -10C across western Lake
Superior beginning Sunday night and continuing into Monday.  Ample
instability along with deepening moisture will help support the
development of locally heavy snows, especially along the higher
terrain of the western to central U.P. into far northern Wisconsin
Sunday night into Monday, with the threat for accumulating snow
gradually spreading farther east Monday into Tuesday.  For the
two-day period ending Tuesday morning, WPC PWPF indicates that
accumulations of 4 inches or more are likely across the western to
central U.P., with a significant threat for localized amounts of 8
inches or more, especially for areas just east of Keweenaw Bay. 


The probability of significant icing is less than 10 percent.

Pereira