Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
230 PM EST Wed Feb 09 2022

Valid 00Z Thu Feb 10 2022 - 00Z Sun Feb 13 2022

...Great Lakes...
Days 1-3...
Upper ridging in the Pacific Northwest and the northwestern
Atlantic will favor continued/renewed troughing over the Great
Lakes for the next few days. Lead cold front and trailing
secondary front over the eastern and central Great Lakes,
respectively, this evening will bring favorable winds across the
lakes for some lake effect snow, especially into the Tug Hill
region on Thursday where probabilities of at least 4 inches of
snow are moderate.

Next system currently over western Canada will dive southeastward
on a 130-150kt jet into northern MN tomorrow evening before
dipping through Michigan and back into Ontario. System will have
sufficient moisture but mostly confined to the warm sector though
precipitable water values around 1/3 inch (+1 sigma) will skirt
through northern MN into WI and the U.P. of Michigan as low
pressure pushes through. Warm advection and broad column lift will
support a few inches of snow in these areas from the system itself
day 2. Once it passes the western Great Lakes, northerly flow
across Lake Superior will restart the lake-effect machine into
favored areas, including the western short of the Lower Peninsula.
WPC probabilities of at least 4 inches of snow on day 2 are
moderate to high over the western U.P. but low to moderate on the
western side of Lower Peninsula. Multi-day totals will exceed 6
inches in some lake belt areas.


...Northern Rockies/High Plains...
Days 2-3...
Southwest side of the upper trough over the Great Lakes will
support some light snow along/east of the Divide days 2-3 near the
tail-end of a couple cold fronts as mid-level shortwaves sprint
through the area. SD Black Hills have the highest chance for more
appreciable snow day 2 (perhaps 6 inches or more) but only a few
inches are expected over higher elevations of MT/WY/CO.


For Days 1-3, the probability of significant icing is less than 10
percent.

Fracasso