PM All Zones: Squalls today as powerful system passes

As we move towards the halfway point of the workweek, a powerful northern stream disturbance will move through the region this afternoon. This disturbance began its journey to the Northeast US from the Northern Canadian/polar regions, and it is dropping very far south as a result of a disturbed arctic weather pattern and a strong ridge near the West Coast of the U.S.A. This disturbance will drop south and eastwards through New England tonight.

Most notably, perhaps, is the fact that this disturbance is missing a phase with a southern stream disturbance over the Mid Atlantic states, which would’ve forced the development of a much bigger and more powerful storm system. Nevertheless, its passage this afternoon and evening will lead to the the development of snow and rain showers.

Showers and snow squalls will move through the region this afternoon.

Showers and snow squalls will move through the region this afternoon.

These will move from west to east through this evening, with colder air filtering into the region as west/northwesterly winds begin to develop. This is a process known as cold air advection, or the movement of colder air into multiple levels of the atmosphere. Blustery winds will follow as well, with the cold conditions expected to continue into tonight.

Wintry impacts beyond snow showers and squalls will be limited to New England. Here, the development of a coastal storm system in the Gulf of Maine (where have we heard that before) will lead to the potential for bands of moderate to heavy snow. This will be particularly noticeable in parts of New Hampshire and Maine, where another round of significant snowfall and impacts are expected.

Closer to our zones, however, the impacts will be limited to the showers and squalls today — and cold air tonight. The storm system will then deepen to our northeast and cause some blustery conditions, but its eventual northeastwards drift will lead to reduced impacts by Thursday.

GFS model showing a warmer pattern taking over across the Central and Eastern USA.

GFS model showing a warmer pattern taking over across the Central and Eastern USA.

Thereafter, the weather will take a more tranquil and warmer turn. The same ridge over the West Coast which was responsible for driving the polar disturbance southwards today will collapse eastwards, rolling over into the Central and eventually Eastern U.S.A. This is significant for a few reasons. First, it allows Pacific, maritime air to move eastwards with the ridge circulation as it collapses. But second, it also cuts off the arctic and polar air source into the Northern 1/3 of the U.S.A, at least temporarily.

With that in mind, confidence is high in a  warmup over the next several days beginning late this week and continuing into the weekend. As the ridge rolls close to the Northeast, in fact, temperatures will reach several degrees above average (or more). High temperatures in NJ and NYC on Sunday may approach 60 degrees.

This warm air looks likely to hang around into the beginning part of the next work week as well, with any wintry or high precipitation hazards out of the picture for several days. In times like these we like to make things a little more simple: Enjoy it! We’ll have the details on temperature and any isolated/scattered hazards that may develop after today — but the overall idea is a tranquil, warmer weather pattern is on the way.