Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 345 PM EST Fri Feb 25 2022 Valid 00Z Sat Feb 26 2022 - 00Z Tue Mar 01 2022 ...Northeast... This Evening... Energy is translating east to the coastal low that has become the dominant feature of the large winter storm and will lift away from southeast Mass rest of this afternoon. The only accumulating snow potential after 00Z is for continued wrap around into eastern Mass with 20% probabilities for an additional inch over Cape Cod where bay enhancement is expected. Day 2... A cold front crosses the Northeast Sunday. This front looks to have enough wind, low level moisture and instability to raise the snow squall threat along and just behind the front. The interior Northeast, northern New York (mainly north from Lake Ontario) through interior northern New England looks to be affected by these briefly heavy, but impactful snow squalls that often cause major travel disruption. As is usually the case, the probabilities for over 2" are not all that high (outside of western facing terrain in the Adirondacks and Greens that has upslope enhancement), but it's that this snow falls in less than an hour for most places is why it's so potentially impactful. Please see the Key Messages statement below for further information. ...Pacific Northwest... Days 2-3... The return to an active pattern for the Pacific Northwest begins Saturday night as a shortwave trough from the northeastern Pacific streams northeastward into WA/OR early Sunday. This wave will have ample moisture on southerly flow but will weaken quickly in advance of the next front that arrives Sunday night. There is considerable uncertainty for the second wave with the 12Z ECMWF much farther east/into Vancouver Island Sunday night and the 12Z GFS much farther west/into Haida Gwaii late Monday and the 12Z CMC/UKMET/NAM clustered in between. A preference for that cluster is a reasonable approach at this time which would focus the main precipitation more into WA and later on Monday. Generally speaking, snow levels around 4000ft with the first wave Saturday night rise to over 5000ft for the second wave Monday. WPC probabilities (which would not have the 12Z ECMWF yet) focus probabilities for heavy snow over the higher WA Cascades/Olympics for Days 2 and 3. Jackson Key Messages: - A strong cold front will sweep through the Northeast Sunday into Sunday evening. - Snow squalls are likely to move southeast along and behind this front across northern portions of New York and New England. - Intense but brief snowfall rates up to 1â€/hr and wind gusts over 40 mph will be possible with these snow squalls. - The combination of intense snowfall and strong winds with already frozen roads would lead to quick and severe reductions in visibility and snow covered roads and particularly hazardous travel conditions. - Any wet roadways will quickly freeze back over as temperatures fall well below freezing late Sunday.