A large arctic airmass, owing to a piece of the polar vortex, will drop southward late this week and weekend from Canada into the Great Lakes and Northeast United States. With it will come the coldest air of the winter — and the coldest air in quite some time, especially aloft. Temperatures at 850mb, or roughly 5000 feet, will drop to nearly -30 degrees celsius, challenging some records for temperatures at that level in the Northeast US for the date.
A powerful coastal storm will shift east/northeast this afternoon, toward the Northwestern Atlantic Ocean, with lingering impacts expected in our area. This will be especially true for coastal sections of Eastern Long Island, where bands of snow may linger until the evening hours of Monday as the coastal low pulls away. Elsewhere, relatively benign weather will take over with gusty winds in the wake of the storm system — but no further accumulating snow.
Despite the departing storm, there are several other weather events to speak about during the upcoming work week. They begin with a weak coastal storm from Tuesday into Wednesday, and end with bitter cold and a possible coastal storm threat this weekend.
What a turn around this winter has been able to pull off over the past week or two. Record-breaking warmth in December gave way to arctic blasts and a historic, crippling blizzard this month. We also saw an atypical fantastic performance prior to the blizzard by the NAM model for this region. We warned the winter could return with a vengeance in a public article we wrote shortly after Christmas. Pattern signals and ensemble guidance were strongly hinting at opportunities for more cold and snow.
While many aspects of our Winter Forecast published in November have worked out, there have been setbacks and surprises as well. This post will serve as an update and stepping stone for the several weeks of winter still left to come.
Winter has finally arrived. Despite potentially record breaking warmth for one day this weekend (Sunday), and the return of rain this weekend as well, we will continue to transition into a colder pattern with an arctic frontal passage on Monday. The atmospheric global circulation pattern is trending much more favorably for winter weather lovers — with teleconnections favoring cold being dislodged into the Northern 1/3 of the United States. With high latitude blocking also in the forecast on all medium range models — the question now becomes: What about the snow?