Evan Belkin

Following up from my discussion yesterday, the biggest uncertainty is in the exact evolution of the TPV emerging out of Canada: - how quickly does the TPV become negatively tilted? - how far south/west does this occur? Broadly speaking, scenarios range from the following: Scenario 1: More progressive and weaker TPV digs into the SE US and only becomes negatively tilted offshore, with a minor-moderate snow event over the Carolinas & heavy snow well offshore Scenario 2: TPV is stronger and farther west, becoming negatively tilted over the SE US & forcing rapid cyclogenesis just off the Carolinas, with a major Carolinas/VA snowstorm and moderate snow farther up the coast as the decaying post-occlusion low tracks northeast Scenario 3: TPV is even stronger and farther west, with the latitude of negative tilt shifted a bit north, favoring a major coastal snowstorm up to Maine primarily south/east of I-95 but possibly including the big cities

12Z GFS at F114.

Very strong signal for impactful icing across much of the Northeast U.S. Locally, some of the highest impacts are forecast across the Adirondacks where the WSSI now has major impacts forecast. I wouldn't be surprised to see an Ice Storm Warning upgrade for the Adirondacks.

As of today, there is at least a non-negligible signal for two possible snow events in the NYC metro this weekend. This analysis will look into whether a miss to the south or the north is more likely, if one or both signals vanish, or if one or both could finally do the trick 🧵

18Z HRRR brings surface warm air up Hudson Valley and squashes snowfall totals to under 4" in Capital District. This occurs during potential peak snowfall rates. Will be interesting to see if the isallobaric/northerly winds can keep the cooler air in place.