Mild this week, but still with a couple of winter weather chances as stormier pattern returns late week

Plain-language summary:

 

After a weak clipper today rapidly kicks out the intense arctic air mass over the region, it will be rather mild for most of this week. Aside from a little rain and snow tonight into tomorrow morning and Tuesday night into Wednesday morning, it will be mostly dry through Thursday. However, two potential storms could affect the region from Friday into the weekend, with the second one still being uncertain if it even will occur. The first storm will likely bring mostly rain late Thursday into Friday, perhaps except for snow and ice in Quebec and northern Maine and at the onset farther south. There could be a second storm, a potential Nor’easter, that would bring more widespread snow over the weekend, but this is more uncertain. After a brief cold shot around that time, there is the potential for multiple storms the following week bringing rain, snow, and ice depending on their tracks.

Meteorological discussion:

After a stormy last 3 weeks of January, it suddenly quieted down as arctic air finally made a big appearance earlier this past week, with some record lows and especially record low wind chills. However, the arctic air was short-lived and is rapidly retreating back into central and northern Quebec as a weak clipper passes just to the north, leading to milder southwesterly flow today. Despite the clipper system and warm advection, the lack of moisture is precluding much precipitation, though light intermittent snow is expected for parts of eastern Ontario, southern Quebec, and northern Maine today into tonight. It might briefly mix with rain in northwestern New York and southwestern Quebec. Light snow is expected on the back side for the Adirondacks and Green and White Mountains late tonight into tomorrow before a modified arctic air returns with high pressure cresting Monday night.

Source: TropicalTidbits

A slightly stronger system will pass well to the north Tuesday night, but may have a little more moisture to produce more widespread rain in northwestern New York and eastern Ontario and snow farther east. It will be fast-moving and also relatively moisture-starved, so accumulations will be no more than 2” (5 cm) for most, with the most being in the higher elevations as lower elevations get shadowed slightly with the strong southwesterly flow aloft. The system will bring more mild air from the southwest, with little cold air in its wake with continued westerly flow.

Source: TropicalTidbits

The bigger story will be two potential storms later in the week: one on Thursday/Friday and one over the weekend. The setup is a bit complicated as usual, and models have yet to hone in on a consensus on the tracks and strengths of either one, especially the second one, or even if there will be a second storm. The first storm has very little cold air to work with, with the cold air having retreated to central/northern Quebec beforehand, though there could be a sneaky low-level intrusion of cold air right before the storm’s arrival. As such, the associated snow zone will be narrow. For now, most models indicate that the low pressure will strengthen in the southern Plains and rapidly move north-northeastward into the Great Lakes before sliding east and slowly weakening. This, combined with the lack of cold air, is not favorable for snow for our region, though there could be a little snow and ice at the onset if there is just enough cold air to start. Northern Maine and parts of Quebec north of the St. Lawrence River are more likely to see a longer period of snow and could stay all snow. If a cold low-level intrusion can push southward a little faster as the storm comes in, snow would be possible a little farther south. Still, a thaw with rain is likely for many, especially south of 45°N, though the most intense surge of warmth should be confined to southern New England on south due to the storm’s occlusion and cold, modified arctic air slowly filtering in on the storm’s back side.

Source: TropicalTidbits

Source: TropicalTidbits

 

The second storm could form as another piece of energy not far behind the first storm dives into the Rockies and Plains. This storm will initially be weak, but if the piece of energy can amplify the trough and be assisted by another northern piece diving in to the northwest at the right time, it would lead to a strengthening storm tracking from the mid-Mississippi Valley to the Ohio Valley and then the mid-Atlantic coast, where the upper-level trough would turn negatively tilted and combined with the warm Gulf Stream water, would form a quickly-strengthening Nor’easter. It is uncertain if the pieces will interact favorably for this to occur, or if the northern piece moves too fast and leaves the southern piece behind and too weak to lead to significant precipitation. If a significant storm develops, it would provide more widespread snow, given more cold air filtering in behind the first storm.

Source: TropicalTidbits

Whether the second storm occurs or not, a relatively brief cold shot will occur around this time. The southeast U.S. ridge is expected to return for a time the following week, while cold air returns to western and central Canada. This is likely to lead to a zone of storminess from the Plains to Quebec, with rain, snow, and ice likely from perhaps multiple storms depending on their tracks, though of course it is way too early to pin down details. Like most of the winter so far, it looks to be generally warmer than average in our region. However, it is unclear if it will be very mild with mostly rain events or only slightly mild with mostly snow events.

Source: TropicalTidbits