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

Valid 00Z Sat Feb 12 2022 - 00Z Tue Feb 15 2022

...Great Lakes...
Days 1-2...
Low pressure moving into Ontario will veer winds over southwestern
Lower Michigan and northwestern Indiana to NNW post-FROPA,
supporting a narrow band of snow that may bring several inches to
the localized area. This will weaken into day 2 with only minor
accumulations.

...Northern Rockies/High Plains...
Day 1...
Fast-moving shortwave trough digging through the central Rockies
into early Saturday morning will support some light snow
along/east of the Divide across Colorado and into northeastern New
Mexico. Totals in excess of 6 inches are likely over the Sangre de
Cristos with light/minor accumulations up to about a couple inches
across the Front Range.

...Mid-Atlantic/Northeast...
Days 2-3...
Shortwave trough over the Mid-South Saturday evening will move
through the Southeast and weaken as additional northern stream
height falls dig into the southern Appalachians on Sunday.
Northern/southern stream jets will support low pressure
development along a front astride the Carolinas that tracks
offshore in progressive flow. Broad lift will support generally
light QPF across the coastal plain with enhanced amounts over the
central Appalachians/Blue Ridge via convergent flow. System will
move northeastward with potential for trailing development
southeast of New England, perhaps enhancing some snowfall over
Cape Cod into day 3. WPC probabilities for at least 4 inches
remain low (10-40%) focused over western VA and eastern WV as well
as across Southern New England.

...Northwest...
Day 3...
Upper low and attendant surface front will dive into the Pacific
Northwest late Sun into early Mon downstream of a building
northeast Pacific upper ridge and anticyclonically-curved 150kt
jet. Limited moisture will be a bit offset by better upper
dynamics (sharp height falls and decent upper divergence at the
left exit region of the jet) to support several inches of snow at
higher elevations with snow levels above 2000-3000ft.


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


Fracasso