Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
421 AM EST Mon Mar 07 2022

Valid 12Z Mon Mar 07 2022 - 12Z Thu Mar 10 2022

...Great Lakes and Northeast...
Day 1...
Deformation band associated with a shortwave lifting northeast out
of the central Plains will continue to shift east into the Upper
Great Lakes this morning.  Favorable upper jet forcing overlapping
low-to-mid level frontogenesis will support light to moderate snow
spreading from southern Wisconsin to central and northern Lower
Michigan this morning.  WPC probabilities indicate that at least a
few additional inches of snow are likely across central Michigan,
with a slight risk for additional accumulations of 4 inches or
more after 12Z.

Meanwhile, warm advection precipitation ahead of the system will
spread into the Northeast later this morning, falling as a wintry
mix across northern New York and New England.  While many areas
may change over to rain, a transition back to snow on the
northwest side of the low can be expected across some areas as the
low tracks across the Northeast this evening.  Minor ice
accumulations can be expected across northern New York and New
England, with a few inches of snow possible along the U.S.-Canada
border.

...Western U.S.... 
Days 1-3... 
Beginning tonight and continuing through Wednesday, a steady
stream of embedded shortwaves will amplify a broader scale trough
across the Pacific Northwest and northern Rockies.  Favorable
upper forcing along with increasing low-to-mid level frontogenesis
will support the increasing potential for heavy mountain snow from
the northern Cascades to the northern Rockies.  In the Pacific
Northwest, accumulations of 4-8 inches are likely across the
higher elevations of the Cascades and Blue Mountains, with some
potential for accumulation of a foot or more across the high
terrain by Tuesday.  Along the Rockies, accumulations of 4-8
inches are likely from the northern Idaho and southwestern Montana
ranges to the central and western Wyoming and northern Utah
ranges.  Locally heavier accumulations of up to a foot or more are
possible, especially across the northern Idaho ranges, including
the Bitterroot and Clearwater mountains.  

Models show an amplifying shortwave digging southeast from the
Pacific Northwest into the Great Basin Wednesday night.  This will
shift the greater potential for heavier snow farther south into
the central Rockies.  Favorable upper forcing along with the
southward moving low-to-mid level baroclinic zone will increase
the potential for snow accumulations of 4-8 inches across the Utah
and western Colorado ranges.

...Central Plains...
Day 3...
As the upper trough in the West continues to amplify and dig
southeast, a low-to-mid level low is forecast to drop southeast
into the central High Plains, encouraging inflow into a downstream
boundary over the Plains.  Thermal profiles support snow across
northern Kansas and Nebraska.  While differences in the details
remain, overnight model guidance has moved toward a stronger
consensus, indicating that impactful snow is likely for portions
of the central Plains on Wednesday continuing into Thursday.  By
early Thursday WPC probabilities indicate that accumulations of 4
inches or more are likely across much of western and central
Nebraska.     
 
Pereira