A very stormy week possible

This winter has featured a very anomalous pattern, with strong high latitude blocking controlling the storm track. This week, that same pattern continues. However, the upper low east of New England will break down in the beginning of this week, giving it less influence than the last few storms. A strong polar vortex will be diving south through central Canada, controlling the evolution of shortwaves moving through the polar and southern jets.

There are two distinct events that will affect New England.

1) A weak shortwave ejecting out of the southwest will cross over the southern plains tomorrow. Surface low pressure is currently developing in the southern Rockies and will be shifting east-NE toward Missouri by Sunday night. The low will continue to deepen on Monday, while lifting toward the Great Lakes region. Secondary low pressure will form southeast of Delmarva, and lift north, spreading precipitation into the region on Tuesday. Its track is still uncertain, but models have been keying in on a strong inverted trough focusing an area of moderate to heavy precipitation across New England and New York. With the primary low to our northwest, we still have precipitation type concerns, but mainly inside I95. It should be mostly snow for the interior. A strong blocking ridge to the north will keep this whole thing in place through Wednesday night.

2) By Thursday, a second phase will occur with a lobe off the polar vortex, forming a massive closed upper low southwest of New England. Another shortwave ejecting out of the southwest triggers surface cyclogenesis in the southeast US. This next low gets sucked into the vortex over/south of New England, producing another prolonged period of heavy snow and winds through Friday.

A lot can go wrong still. Model guidance has been advertising some very anomalous solutions for a while. And the HPC discussions grow more robust everyday. The current discussion alludes to New England vaulting into Mid-Atlantic-snowfall territory in one leap. This is not a simple nor'easter with simple track adjustments. Very realistically, snowfall totals for next week could be anything between 4" and 40"

Detailed forecasts will begin later tomorrow in the winter weather outlook.