Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
256 PM EST Sat Dec 30 2023

Valid 00Z Sun Dec 31 2023 - 00Z Wed Jan 03 2024

...Great Lakes...
Days 1-2...

A clipper system will shift southeast from the central Great Lakes
to central Pennsylvania through Sunday night. Lake enhanced snow
will trail the low center as cyclonic flow over the Lakes brings
localized snow bands. Typical snow belts south of Lake Superior
are in play tonight with less typical northeasterly flow over Lake
Michigan bringing snow bands south over eastern Wisconsin Sunday
and Chicagoland Sunday evening. Finally, northerly flow looks to
bring in snow bands into northwestern IN Sunday night. Day 1/1.5
WPC PWPF have 40 to 60% probability for >2" in these targeted
areas with localized 4" possible where the lake effect bands
persist longest.  south from Ontario will strengthen as it tracks
into the Upper Midwest Saturday night. As the low tracks south
into northern Wisconsin, northeasterly flow will increase over
Lake Superior and result in lake effect snow bands over northern
Wisconsin. While other snow showers will breakout in parts of the
Midwest and Great Lakes, it is northern Wisconsin and the western
U.P. of Michigan that will have slightly better odds for heavier
snowfall. WPC PWPF features low-to-moderate chances (20-50%) for
snowfall >2" in these areas. Some slick spots of roads are
possible in areas where heavier snowfall rates occur.

...Central Appalachians...
Day 2...

After a break in the snow Saturday night and into Sunday morning,
the clipper system responsible for snow in parts of the Midwest
and Great Lakes will make its way into the northern Mid-Atlantic
Sunday night. This will bring a rejuvenated surge of upslope flow
and some modest moisture aloft. Periods of mountain snow will
develop once again from the Potomac Highlands on north to the
Laurel Highlands and Allegheny Mountains Sunday night and into New
Year's Day. Day 2 WPC PWPF are 30-50% for >2" of snow in eastern
West Virginia and western Garrett County, MD on north to portions
of the southern Laurel Highlands. Local 4" are possible. WPC PWPF
shows, however, that odds are rather low as probabilities are
topping out around 10%. Some hazardous travel conditions are
possible Sunday night into New Year's Day this next minor
accumulating snowfall unfolds.

The probability of significant ice across the CONUS is less than
10%.


Jackson