Summary for Sunday Snowfall: looking like a 1-3/2-4" event for most in the Philly-NJ-NYC area. We should get full event NWS snow maps at 4 pm, although they appear to be on board for a 1-3" event based on their discussion. Links to the NWS site and the AmericanWx forum thread on this event are below.
Still about 60 hours from the start of the event late Saturday night, which will last through Sunday late morning and almost every model shows at least 1-3" for most of the Philly-NJ-NYC region, with some of the models showing 2-5" for most. Temps should be cold enough for snow for everyone, except perhaps SENJ (where some rain/mix could fall) and with snow falling at night on sub-32F surfaces with air temps at or below 32F, any snow that falls will accumulate on untreated surfaces, so driving conditions will be slippery on Sunday, even if we only get an inch or two. For areas along/NW of 95 the snow will likely be fairly dry and fluffy with ratios above the usual 10:1, snow:liquid.
Too far out to know if we get the lighter amounts or the heavier amounts, as the uncertainty is still too high this far in advance, but it's looking quite likely that we get get at least the 1-3" amounts, with a complete miss now looking unlikely. The difference is in whether all of the precip comes from the upper level vortmax (vorticity/intense rotation that often fuels precip) approaching from the midwest and forecast to go over/near our area by Sunday or whether that system will be enhanced by a surface low pressure system expected to form off the DelMarVa. If that low tracks close enough to our area, we could easily get 3-5" of snow, but if it tracks too far off the coast, we'd likely only get the 1-3" amounts.
https://www.weather.gov/phi
https://www.americanwx.com/bb/topic/62443-minor-snow-possible-sunday-121425/page/5/
Still about 60 hours from the start of the event late Saturday night, which will last through Sunday late morning and almost every model shows at least 1-3" for most of the Philly-NJ-NYC region, with some of the models showing 2-5" for most. Temps should be cold enough for snow for everyone, except perhaps SENJ (where some rain/mix could fall) and with snow falling at night on sub-32F surfaces with air temps at or below 32F, any snow that falls will accumulate on untreated surfaces, so driving conditions will be slippery on Sunday, even if we only get an inch or two. For areas along/NW of 95 the snow will likely be fairly dry and fluffy with ratios above the usual 10:1, snow:liquid.
Too far out to know if we get the lighter amounts or the heavier amounts, as the uncertainty is still too high this far in advance, but it's looking quite likely that we get get at least the 1-3" amounts, with a complete miss now looking unlikely. The difference is in whether all of the precip comes from the upper level vortmax (vorticity/intense rotation that often fuels precip) approaching from the midwest and forecast to go over/near our area by Sunday or whether that system will be enhanced by a surface low pressure system expected to form off the DelMarVa. If that low tracks close enough to our area, we could easily get 3-5" of snow, but if it tracks too far off the coast, we'd likely only get the 1-3" amounts.
https://www.weather.gov/phi
https://www.americanwx.com/bb/topic/62443-minor-snow-possible-sunday-121425/page/5/
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