Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
251 AM EST Fri Feb 11 2022

Valid 12Z Fri Feb 11 2022 - 12Z Mon Feb 14 2022

...Great Lakes...
Day 1...
Low pressure tracking through the Great Lakes this morning will
lift into Ontario later this morning before weakening. Warm
advection light to moderate snow ahead of the low pressure will
bring a few inches of snow to portions of Michigan early this
morning but the bulk of heavy snow risk is associated with lake
effect bands, particularly off Lake Superior where probabilities
of 4 inches or more are high. Weaker flow and less favorable setup
will bring just light lake effect snow to the region for day 2 and
day 3.


...Northern Rockies/High Plains...
Day 1...
Fast moving shortwave trough digging through the Rockies late
tonight through early Saturday morning will support some light
snow along/east of the Divide. The highest and favored peaks of
MT/WY/CO stand chances for locally 4-6 inches as well as the SD
Black Hills. Elsewhere, light/minor accumulations of a couple
inches are possible.

...Mid-Atlantic/Northeast...
Day 3...
Digging 500 mb shortwave trough over the Mid-South Saturday
evening will move through the Southeast by early Sunday near the
entrance regions of the northern (130kt) and southern (110kt) jet.
Frontal boundary along the coast may focus an area of low pressure
that tracks along or just offshore that would spread precipitation
back across portions of the region. There continues to be many
uncertainties ranging from track, phasing, and intensity as well
as thermal profiles as the precipitation changes from rain to
snow. For now, the greatest probabilities for 2 inches lies over
the central Appalachians/Blue Ridge in VA (20-40 percent) while
lower probabilities of 10-20% exist through the Mid-Atlantic to
southern New England.


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

Taylor