12 PM (Noon) Wednesday Note: We've added a 15" contour to Northern Maine and the Maine mountains, so I've updated the maps below. Have expanded snow in Vermont. Otherwise, steady as she goes. Ready and willing to slash numbers lower in Eastern MA if signals become overwhelming that warmth and rain will take over quicker, but not seeing that overwhelming evidence just yet.
Here's where we stand on Thursday's winter storm for New England:
- Snow begins 4-8 AM across most of Southern New England, from southwest to northeast.
- More specifically: Thursday snow will begin ~3AM NYC, ~5AM Hartford, ~7AM Boston, ~8:30 at MA/NH border. So, for many, the early AM drive rolls on before things deteriorate.
- Likely only a brief mix, if that, on Cape Cod before going to rain
- Rain/snow line moves quickly northwest off of Cape Cod Thursday morning, but slams the brakes on when it gets into Plymouth County, thereafter slowly eroding northwest (quicker along immediate South Shore)
- Boston proper will be extremely marginal for snow or rain. At this point, I think the City sees more wet, pasty snow than rain, though some rain will mix in at times. Nonetheless, if we can keep it mostly snow through early afternoon, we can crank out over half a foot in the City, and that's what I've opted to go with for now. The same thinking applies to suburbs south of Boston - I'm expecting wet, pasty snow to hold on longer than most computers suggest, which is why amounts are healthy in these areas, too.
- Heaviest precipitation falls Thursday late morning to evening, but another burst is likely for many predawn Friday morning.
- Wind will be a big factor with the storm - gusts to over 60 mph possible at the Massachusetts coast, gusts to 45 mph possible elsewhere. The result will be scattered power outages in both the rain and snow areas, and bouts of blizzard conditions where heavier snow falls through the interior.
Several maps below:
Southern New England forecast snow:
Zoomed-in view of Eastern MA, focused on sharp difference due to rain/snow line progression - keep in mind, if warmer air wins out quicker than we're thinking, may have to shave back on amounts in the Boston suburbs, but I think this is the best forecast possible right now:
Northern New England forecast snow:
Wind gust forecast Thursday evening:
Friday "wrap-around" weather map depiction, valid around sunrise Friday: