Freezing rain tonight into Monday, then brief thaw for many, before colder for rest of the week with occasional snow showers and squalls; potential next storm likely with snow following Monday; still moderately cold with potential for storms with more moisture afterward though with high uncertainty

Plain-language summary:

 

A storm will bring freezing rain across the region tonight, possibly mixed with snow and ice pellets from the Laurentians to northern Maine, followed by a brief warmup and change to rain from Montreal on southwest on Monday. It will then turn colder again Monday night with scattered snow showers leading to minor accumulations mostly along and northwest of Appalachians through Tuesday. It will remain cold and breezy through Saturday but also mostly dry except occasional snow showers and squalls, most likely on Wednesday and possibly late Friday into Saturday. The next potential substantial storm, likely as snow, would be around the following Monday plus or minus a day, with an uncertain but still moderately cold (typical for January) weather pattern afterward potentially with some storms containing more moisture.

 

Meteorological discussion:

 

Quick warmup with freezing rain tonight changing to rain for most on Monday except far northern areas, then colder again with scattered snow showers with minor accumulation through Tuesday

 

Despite the torch covering most of the U.S., it managed to stay cold but only with moisture-starved clippers for the past few days, as amazingly, Thursday's clipper actually suppressed the system Friday evening too far to the southwest for precipitation for most of our region and also weakened it. The -NAO and -AO are really battling the -PNA's usual influence of bringing storm tracks to the northwest of our region and mild air into the region. 

 

However, a much stronger storm is rapidly strengthening as it heads northeast into the Great Lakes, finally bringing the warm, moist air from the central and southern U.S. into our region. The low-levels are still very cold due to a well-positioned surface high-pressure system over Quebec that has advected cold arctic air directly from the north, which brings the coldest air to our region since the northerly winds are unmodified over the Great Lakes and spend minimal time moderating over lower latitudes. This means that the warm, moist air will overrun the low-level arctic air (albeit becoming stale), with a steep low-level inversion on the synoptic-scale. This means that precipitation will start as freezing rain almost everywhere tonight, even in the typically unfavorable areas like the Champlain Valley (where the southerly winds usually quickly warm it up) and even more so in the St. Lawrence Valley with the low-level cold air being channeled from the northeast and making it last longer there. The Laurentians into northern Maine could see some of the precipitation as snow and ice pellets as the warm air will encounter the most resistance there. The storm will likely meet bomb cyclone criteria, boosted by the relatively warm Great Lakes, and bring 30-50 cm of snow to northern Great Lakes and northern Ontario as the storm center tracks into central Quebec, well to the north of our region. This track means that the heaviest and most prolonged precipitation will go well to the northwest of our region, as our region enters the dry slot of the storm later Monday, preventing this from being a truly major ice storm for most. However, the rainfall rates could be heavy at times, leading to localized areas of >25 mm of freezing rain, especially in terrain-favored areas such as central and eastern Ontario, with channeling of cold low-level air from the northeast, and from the eastern Adirondacks to New Hampshire, with cold air damming. Heavy rain rates usually favor some runoff and not all freezing on contact, though accretion will still be very efficient regardless of rain rates given the extremely cold antecedent conditions and temperatures as low as 18F (-8C) in the aforementioned areas during the freezing rain, which is unusual.

 

Source: TropicalTidbits

 

Source: PivotalWeather

 

 

Temperatures from Montreal on southwestward briefly spike above freezing for a few hours Monday afternoon before colder air quickly moves in from the west Monday night, with the storm occluding, slowing down, and becoming larger in size and more vertically stacked. A broad area of scattered snow showers, especially in higher terrain along and northwest of the Appalachians, will continue as a result through Tuesday night, though only very minor accumulations are expected outside mountain peaks given the unfavorable track of the storm well to the north.

 

Source: TropicalTidbits

 

 

Cold and breezy but mostly dry Wednesday through Saturday, with occasional snow showers and squalls

 

The storm will destroy the incredible central U.S. upper-level ridge. For most of the rest of the week, the storm will transform into a very deep, occluded, vertically stacked, and slowly-moving low over Quebec, leading to a lot of cold and breezy weather in eastern North America but as is typical of recent years, the low will be so far north that it will expend all its never-ending snow well up into Quebec and Labrador, while farther south, it just stays dry with the system suppressing any southern stream disturbance and preventing any real moisture from advecting from the Gulf of Mexico or western Atlantic. There are a couple of disturbances rotating around the closed low that could be enhanced by the warm (relative to the arctic air) Great Lakes and bring snow showers or even squalls at times, with one likely on Wednesday and another likely late on Friday or Saturday. Even then, most indications are that they will be strung out and compete against each other and never form a consolidated and more substantial system, another classic feature of recent winters.

 

Source: TropicalTidbits

 

 

Weather pattern moves again next weekend and beyond with multiple possible storms starting next Sunday or following Monday, but a lot of uncertainty on specifics 

 

The closed low over Quebec will likely accelerate away to the northeast next weekend, though models differ by about a day on exactly when this will occur. As this happens, the southern jet stream appears to become more active, with a storm entering the U.S. West Coast and ejecting into the U.S. Plains and then move northeastward toward our region from there. This appears farther south than most of the storms we have seen eject out of the Rockies this winter so far, allowing it to transport more Gulf of Mexico moisture. Given the right track (e.g. from southwest to northeast, transporting this moisture into our region, which has not happened much this winter so far), this is probably the next chance of substantial precipitation, likely snow given the antecedent arctic air, for our region around the following Monday. 

 

Source: TropicalTidbits

 

 

The overall weather pattern still features high-latitude blocking (-NAO), abundant cold air (-AO), and a weakening -PNA (upper-level troughing in western North America). The blocking can help storms in the southern U.S. turn northward and be blocked from escaping out to sea, though if it is in the wrong configuration, it can also help suppress storms to the south (like January 2025). Even with the -AO, there are indications that the cold air over Canada will weaken, but there is also no support for any sustained thaw in our region, just that the cold air will be less intense, which does not really impede winter storms in January (the climatologically coldest month of the year). Obviously, there is a ton of model disagreement on details beyond next weekend, ranging from storms missing our region to the south with flat, zonal weather patterns to more amplified patterns with storms tracking to our northwest, causing snow to change to ice and/or rain with a brief thaw in our region. However, such a weather pattern likely favors some storminess coming from the southwest containing more Gulf of Mexico moisture as opposed to the moisture-starved Alberta clippers that have been more dominant so far this season (other than the rainstorms), though there is a significant risk of storms missing to the south and east of our region, especially if the upper-level trough/ridge configuration ends up being weaker or farther east than currently indicated.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

Cold and mostly dry through Monday; light to moderate snow Tuesday through Tuesday night; snow, ice, and rain likely Friday and another system likely next Sunday; potentially mild for a short time after but highly uncertain

Plain-language summary:

 

Cold and dry air through Monday, except flurries Monday evening from eastern Ontario to northern Vermont, will be followed by light to moderate snow Tuesday into Tuesday night, except for northern Maine. It will temporarily turn colder Wednesday before a likely warmer system brings snow, ice, and rain depending on location late Thursday into Friday. Another system is likely next Sunday but considerable uncertainty remains. A short-lived milder weather pattern could occur around New Year's Day, but uncertainty is even higher then. 

 

Meteorological discussion: 

 

Cold and dry air today into Monday, then light to moderate snow Tuesday into Tuesday night 

 

The weather pattern full of arctic cold across eastern North America has shifted substantially, with the retrogression of the upper-level ridge in Alaska to the Bering Sea allowing for an upper-level trough over the North American West Coast (-PNA) and +AO promoting a stout and persistent upper-level ridge in the central U.S. But with the core of the upper-level ridge well to the southwest of the region, arctic air just to the north over Canada still in abundant supply, and -NAO associated with eastern Greenland blocking pushing the jet stream just far enough south into New England, winter is still alive in our region. A clipper passing to the north over central Quebec brought light snow and a snow squall along the cold front to northern areas last night into this morning, but this afternoon, it is just dry with a shot of cold (perhaps not arctic) air into the region, except lingering snow showers in the mountains. However, another relatively weak and elongated disturbance will already be approaching from the Rockies and diving east and then southeastward Monday into Tuesday. Systems like this coming from the west and northwest typically do not bring much precipitation with limited moisture from that direction, though the strong temperature gradient will enhance dynamics with the warm advection, and there is just a little moisture coming from southern U.S. After a few flurries from eastern Ontario to northern Vermont Monday evening, this will result in a stripe of light to at times moderate snow across the region, except northern Maine which will be too far northeast of the low-pressure track. Models have been in surprising disagreement on the evolution of this system until this afternoon.

 

Source: TropicalTidbits

 

Another likely warmer system Friday, but a lot of uncertainty remains 

 

Colder air returns behind the system, but it will not be as cold with less southward penetration due to the central U.S. upper-level ridge strengthening further. Another system coming from the Pacific will eject from the northern Rockies and move east or southeastward into our region on Friday, likely farther north than Monday-Tuesday's system. This increases the likelihood for mixed precipitation or even rain south of the Montreal to Bangor line, with snow and ice more likely to the north. However, it will be several more days before specific details will be known with any confidence. Any cold shot behind this system will be very limited due to the upper-level ridge that is still very strong in the central U.S. with another system ejecting from the Rockies promoting warm advection again next weekend. That system would likely arrive in our region next Sunday and appears to track north of our region (though not a certainty yet), promoting either the heaviest precipitation to go to the north of our region, precipitation type to be mainly ice or rain, or both.

 

Source: TropicalTidbits

 

 

Source: TropicalTidbits

 

 

Possible short-lived milder period around New Year's Day, but tremendous uncertainty on specifics and any possible storms 

 

Over time, the axis of the central U.S. upper-level ridge will likely push farther east into the eastern U.S. around New Year's Day, which could allow more of the warmth to enter our region after a few days of relatively dry weather, though the ridge will likely be weakening. If the ridge is a little weaker, it could allow for the more traditional southwest to northeast storm track bringing wintry precipitation to our region, but if the ridge is stronger, it could just flood the region with milder air with periodic rain. There is tremendous run-to-run inconsistency and uncertainty in the long-range, enough so that even mere chances of storminess are hard to pin down. There are some signs of the AO turning at least neutral around that time, which could allow more of the arctic air to penetrate farther into the U.S. and render the thaw short-lived, but long-range ensembles indicate that the arctic air will likely still retain its focus in western Canada, with a little bit of southeast U.S. ridge providing resistance to southward penetration of cold air in the eastern U.S., though that could promote a stormier weather pattern in our region with more access to Gulf of Mexico or western Atlantic moisture.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

Cold weather continues for another few days, with snow showers and squalls today and light snow Monday night in northern areas; then turns milder Wednesday through Friday with rain Thursday night into Friday; turns colder likely with frequent but not major wintry precipitation events

Plain-language summary:

 

The amazingly persistent and intense cold weather pattern will continue for another few days, with snow showers and squalls for areas along and northwest of Appalachians today, very cold and dry weather Sunday and Monday, and a bit of snow for areas along and northwest of Appalachians on Monday night. Then, it turns milder Wednesday through Friday with rain Thursday night into Friday, likely the first rain of the month for most northern areas. It then turns colder again but with the most intense cold staying to the north and mild weather staying not too far to our south, leading to our region likely experiencing frequent bouts of wintry precipitation into the following week, though major storms do not appear likely.

 

Meteorological discussion:

 

Snow showers and squalls for along and northwest of Appalachians today, then cold and dry through Monday before a bit of snow Monday night 

 

Arctic air is still in picture for a few more days. A weak and elongated Alberta clipper centered over western Quebec will lead to snow showers and even squalls mostly along and northwest of the Appalachians today, with the still warm Lake Ontario enhancing the snow in eastern Ontario and southern Quebec, the most in the upslope areas of the southern Laurentians. However, another disturbance to the south will take over and bring a few hours of light to moderate snow to southern New England late tonight, but as with any potential coastal storm so far this year and most recent winters, it will strengthen much too late and be much too suppressed to produce any big snow for anywhere in New England given the suppressive west-northwesterly flow. Instead, another dry and cold arctic air mass coming straight from the northwest will envelop the region Sunday and Monday, though with another weakening clipper bringing just a bit of snow Monday night along and northwest of the Appalachians.

 

Source: Aviation Weather Center

 

 

Source: TropicalTidbits

 

 

Turns milder Wednesday through Friday with rain Friday 

 

A big weather pattern change then ensues starting Wednesday. The prominent Alaskan upper-level ridge that brought all the cold arctic air to our region over the past few weeks will retrograde westward to the Bering Sea, which means cold air still floods North America, but the upper-level trough gets focused along the West Coast instead of in eastern North America. This promotes upper-level ridging in the central and southern U.S. with a surface low-pressure track to the north bringing westerly flow of mild Pacific air. The first such mild surge will reach our region later Wednesday as a strong low-pressure system tracks way to the north over central Quebec, so far north that little precipitation will fall, though any precipitation in northern areas could still fall as wet snow given the limited time for moderation of the arctic air and the deep snowpack over our region. Though a brief cooldown follows for Thursday, another fast-moving strong low-pressure system taking a similar track will bring a stronger mild push from the south and southwest with more moisture, leading to more widespread rain Thursday night into Friday, the first rain of the month for many especially along and northwest of the Appalachians. 

 

Source: TropicalTidbits

 

 

Winter returns next weekend into following week but extreme cold is not as dominant, with frequent opportunities for wintry precipitation though big storms appear unlikely

 

However, arctic air looks to push back into the region later Friday, and from then on, the upper-level ridge could be more confined to areas just southwest of our region, with the slight Greenland blocking still favoring enough upper-level troughing over Atlantic Canada to keep the cold arctic surface high-pressure systems to sneak in from the north and prevent any real torch in our region. The resulting dominant west-northwesterly flow isn't too favorable for big storms or any storm tapping into much Gulf of Mexico or Atlantic moisture, much like the last several weeks, though the strong temperature gradient favors frequent, fast-moving clippers with stronger dynamics/forcing for ascent than usual for clippers and could still lead to heavy precipitation rates in relatively small areas within storms. So it could still be stormier and snowier than typical even without any truly big storms. One such storm appears likely next weekend that could bring a decent amount of snow changing to ice and/or rain for many locations, though current models have the surface low too far north for the best dynamics and precipitation in our region, and it is way too early for details. Arctic air will follow again behind that storm but not advance too far south, with the coldest air likely remaining to the north, given the upper-level ridge to the southwest, with more storms likely riding along the temperature gradient and affecting our region the following week bringing wintry precipitation given the arctic air around.

 

Source: TropicalTidbits

 

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

Persistent series of Arctic air masses through at least next weekend before uncertain potential short-lived thaw following week, but could also turn stormier; swath of light snow through tonight, then snow especially northern areas Tuesday night into Wednesday night, then mostly dry through weekend with possible occasional light snow

Plain-language summary:

 

The region is experiencing an incredibly persistent weather pattern featuring one Arctic air mass after another for the foreseeable future. A swath of minor fluffy snow will occur this afternoon into tonight from southeastern Ontario to central Maine before it turns very cold Monday night. Temperatures quickly moderate through Wednesday night with snow for many, with the heaviest occurring north of the U.S./Canada border and especially in the St. Lawrence Valley and Laurentians. It then turns very cold again through at least next weekend, but it appears relatively dry, though occasional light snows are possible. There is the potential for a thaw for the following week, but it is unlikely to last long and could be pushed south of our region and lead to a stormier weather pattern instead.

 

Meteorological discussion:

More arctic air through Monday, swath of light snow from eastern Ontario to central Maine this afternoon into tonight

The incredibly persistent weather pattern featuring one Arctic air mass after another continues. A very weak low-pressure system, enhanced by the still warm waters of Lakes Huron and Ontario, will bring a swath of 1-4" (2-10 cm) of snow from southeastern Ontario through central Maine this afternoon into tonight, with very cold Arctic air behind it. Despite the lack of moisture, the cold temperatures and strongest ascent through the dendritic growth layer (the portion of the atmospheric column between -10C and -20C) favors the formation of large dendrites that have a lot of air pockets and can stack up quickly even with little water content, with snow-to-liquid ratios up to 25:1 being possible, in areas in which any banding sets up where stronger ascent and heavier precipitation rates occur. Outside of those zones, the weaker ascent could still favor small snowflakes. Monday night could be as cold as Thursday night for many, with temperatures below 0F (-18C) outside urban areas and away from major bodies of water.

 

Source: Aviation Weather Center and TropicalTidbits

 

 

Clippers to bring milder temperatures and moderate snowstorm for northern areas and higher elevations Tuesday night into Wednesday night 

 

The extreme cold will not last long, as a series of two Alberta clippers will dive southeastward into the Great Lakes by Tuesday, bringing southerly flow of somewhat warmer air. The first clipper is weaker but will still bring light snow Tuesday night given the warm advection into the Arctic air mass, especially in the Adirondacks on northward where the dynamics are stronger. The second stronger clipper will dive a bit farther south and then recurve slightly to the east-northeast straight into the St. Lawrence Valley on Wednesday. This slight curvature, as opposed to a pure east-southeast motion, allows the storm to pick up a little Gulf of Mexico moisture while it tracks farther south in the Midwest U.S., and the overall setup leading to the east-northeast motion afterwards leads to stronger ascent and precipitation. As such, a swath of 4-8" (10-20 cm) of snow is likely along and just to the north of the low-pressure track, mostly north of the U.S./Canada border, with the Laurentians and St. Lawrence Valley likely receiving the heaviest due to both ideal storm track and terrain-induced low-level convergence. Upslope areas of the southern Adirondacks could also receive large accumulations from heavy snow at the start of the storm. To the south of the low-pressure system, a period of snow will be followed by slight drying and a brief thaw with southwesterly flow, though higher elevations will continue to receive snow. The Champlain Valley will likely get downsloped for a time Wednesday evening due to the southwesterly flow, leading to less precipitation. A little snow is likely on the back side for areas along and northwest of the Appalachians later Wednesday night.

 

Source: TropicalTidbits

 

 

More Arctic air and mostly dry later Thursday into next weekend, though weak clippers could bring occasional light snows 

 

Yet another arctic air mass blasts in behind the clipper, lasting likely at least several days starting later Thursday into next weekend. The main contributor is continued upper-level ridging in Alaska (-EPO) promoting arctic air to continuously spill into the mid-latitudes. The upper-level ridge near the U.S. West Coast (though not penetrating northward enough into Canada to register as a +PNA) and slight Greenland blocking (-NAO) are helping but may be of secondary importance in this case. This time, the upper-level trough in eastern North America is so deep that it will cut off any Gulf of Mexico moisture, overwhelming the region with dry northwesterly flow. However, weak clippers could still produce occasional light snows, with the cold temperatures leading to higher snow-to-liquid ratios and a fluffier snow that can accumulate efficiently even with relatively little moisture.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

 

Uncertain potential for short-lived thaw following week, but could also be stormier 

 

For the following week, there are signs that the weather pattern will loosen or shift westward at least temporarily, with the Alaskan upper-level ridge shifting west into the Bering Sea some upper-level troughing entering the western U.S. (PNA turning slightly negative), which will promote an upper-level ridge downstream to build over at least the central and southern U.S., but it remains unclear if the thaw can actually push northeastward into our region. It will certainly turn milder for Monday and Tuesday of following week as another clipper approaches or tracks to the north of our region, but it is unclear how intense or sustained any warmer weather is. It is possible that the little Greenland blocking and some upper-level troughing over Atlantic Canada is just enough to shove the warmth southeastward into the southeast U.S., like in November, with our region being in the battleground between the mild air to the south and still Arctic air to the north, in which case we could actually receive stormier weather with precipitation type dependent on details that are way too early to determine. If it is configured right, it could actually be a snowier weather pattern with multiple opportunities for decent snowfalls, and if the thaw instead does reach our region, most indications are that will not last long, with Arctic air never far away to the north and ready to rush in behind any cold front. But even then, there looks to be more of a presence of at least some upper-level ridging in the southern U.S., meaning that deep upper-level troughs overwhelming all of eastern North America with dry air are less likely, raising the possibility of battleground storminess, snowy weather (given all the Arctic air around), as well potential additional thaws.

Source: TropicalTidbits