3.5 Afternoon All Zones: Cold now, active pattern ahead

Very cold weather settled into the area on Saturday, with temperatures running well below normal throughout much of the Northeast United States. A deep trough swinging through New England brought arctic air into the area, with brisk northwest winds making the air feel colder than it already was. This cold is meandering across the region today, and will gradually move away over the next few days.

The warmup will continue with moderating temperatures as the midweek period approaches. Temperatures will rise near and then above normal by the first two days of the week. A strong storm system developing over the Central United States is expected to shift into the Great Lakes, drawing a notable southwest flow towards the area in the mid and lower levels of the atmosphere. Another severe weather event is expected to unfold across the Central US as a cold front approaches the Ohio Valley and eventually Northeast.

GFS model showing rain with a cold front in the Northeast US on Tuesday.

GFS model showing rain with a cold front in the Northeast US on Tuesday.

The aforementioned cold front makes its approach to the Northeast states on Tuesday. Increasing moisture and lift in the atmosphere will lead to showers on Tuesday ahead of the front, with forecast models suggesting a dreary day especially in New England, where low level moisture and clouds will remain stout. The front approaches later in the afternoon on Tuesday, with a round of showers swinging eastwards from Pennsylvania into the Northeast states from west to east.

Instability parameters are currently forecast to be quite low, but the potential for some thunder does exist with the strong dynamics associated with the storm system (sound familiar?). Either way, Tuesday evening will feature a cold frontal passage with likely a steady period of rain throughout the Northeast and northern Mid Atlantic.

Cold air shifts into the region behind the frontal boundary passage, establishing itself in the Northeast on Wednesday. But the evolution of the pattern well to our north, throughout Canada and the arctic regions, will begin to have major implications on the forecast as we move towards the end of the week. High latitude blocking, with ridging moving into Greenland and the Davis Straight region, will begin to force colder air (which typically stays bottled up in the arctic) southwards into Canada. It will also begin to re-direct the jet stream to allow for more potent disturbances to move into the Eastern United States.

GFS model showing the polar blocking ridge which currently exists over Greenland and is adjusting the atmospheric height pattern.

GFS model showing the polar blocking ridge which currently exists over Greenland and is adjusting the atmospheric height pattern.

With cold air plentiful to our north, a high latitude block in place, and multiple disturbances approaching, the period of time we have discussing for a few weeks now — around Mid March — looks likely to hold the potential for wintry weather. We’re keeping a close eye on individual threats, which begin to appear on forecast models by the end of this coming week into the weekend. You can read our latest medium range forecast update on the details of blocking and why we anticipate wintry threats coming up!

Stay tuned for further updates over the next few days as we draw closer.