As you've perhaps heard by now a classic nor'easter is about to head up the coast and bring blizzard conditions to our area tonight and tomorrow. The storm, which brought snow across the southeast over the weekend is now moving off the North Carolina coast and is pushing tremendous amounts of tropical moisture ahead of it. Unlike this past weekend, or the pre-Thanksgiving storm last fall, there is plenty of cold air already in place so that there will be no switch-over to rain once the storm gets here.
The National Weather Service has just increased expected snowfall to 24-36" for Brooklyn, Queens and the Bronx. (The NWS forecast model still predicts 18-24" in Manhattan and Staten Island.) The official record was set in 2006, when 26.9 inches were registered in Central Park.
The blizzard warning goes into effect at 1 p.m. today and lasts through midnight tomorrow night. The heavy snow could start as early as 2 p.m. on Long Island to as late as 6 p.m. in the city. With the amount of moisture available some spots could see snowfall rates of 2-4 inches per hour overnight and well into Tuesday. The city, Long Island and northern and western suburbs are likely to see 2-3 feet of total snowfall as the forward progress of the storm stalls out near Cape Cod, leading to an extended period of snowfall.
Fixating on the total snowfall amount is a bit silly. Sustained winds of 20-30 mph with gusts to 45-50 mph will move that snow around and create drifts several feet high. The wind, the snow and the cold weather—tonight's low will be around 20 with wind chills in the single digits—will make any sort of outside activity tonight and tomorrow extremely hazardous.
The sun is expected to return on Wednesday but it will be cold. Look for a high in the upper 20s. An Alberta Clipper might add a couple of inches to this season's snowfall totals on Thursday or Friday. More importantly that clipper is going to bring in a polar air mass. Look for a high around 20 degrees on Saturday and mid 20s on Sunday.