Milder and mostly dry today into Monday; then stormy through next weekend with rain except wintry mix in northern areas Tuesday into Tuesday night; potential big storm Thursday into Friday with snow changing to rain; milder with rain next weekend; then more typical April weather with occasional rain, lack of real cold, and little or no snow

Plain-language summary:

 

After being dry and unseasonably cold Friday and Saturday, it will turn milder but not particularly warm later today into Monday, with it remaining dry except light scattered snow showers mainly in northern areas. It will then be rather stormy through next weekend. Tuesday into Tuesday night will be rainy except a little snow to wintry mix possible in northern areas from central Quebec to northern Maine. It will turn cooler and drier on Wednesday before a widespread potentially big storm bringing snow to wintry mix to rain occurs late Thursday into Friday, with the best chance of a big snowstorm from central Quebec to northern Maine. It then turns warmer with rain next weekend before it turns cooler, but without much if any arctic air to the north to tap into, leading to a more typical April weather pattern with occasional rain chances but likely little if any snow especially at lower elevations.

 

Meteorological discussion:

 

Milder but not particularly warm later today into Monday but staying mainly dry; rain to south and wintry mix to north on Tuesday

 

March has been characterized by a huge temperature contrast between persistent arctic air over central and northern Canada and record-breaking heat in the western and central U.S. This persistent temperature contrast is characterized by a -PNA, +AO, and +NAO, virtually the opposite of most of the past winter. This battle will continue for the next week and play a key role in the weather in our region. The largely dry arctic air mass of Friday and Saturday is moving out with little or no precipitation except light scattered snow showers in northern areas with little or no accumulation. This fits the theme of the winter of it being difficult to ram rich Gulf of Mexico or Atlantic moisture into the cold air masses in our region. Dry southwesterly flow will bring milder air later today into Monday, with a weak surface low-pressure system passing to the north on Monday carrying its precipitation mainly north of our region. The warmer air will fall well short of the incredibly warm temperatures to our southwest. A cold front will pass Monday night, and arctic air will try to push in again, but like most of this month, the upper-level ridge to the south will be too strong for the cold front to advance much, with the ridge actually centered over the southeast U.S. instead of farther west like last week. Therefore, the front will stall over our region as another somewhat stronger but elongated, more moisture-rich low-pressure system advances from the west. With an arctic surface high-pressure to the north over northern Quebec and the surface low-pressure system passing through our region, widespread precipitation will occur on Tuesday and Tuesday night, mainly as rain for most of the region given that the cold air is not really able to advance southward much before the precipitation arrives. However, northern areas deeper into the cold air, from central Quebec to northern Maine, could receive a bit of snow changing to a wintry mix of ice pellets, freezing rain, and rain. Low-level cold air channeled southwestward through the St. Lawrence Valley could lead to freezing rain there especially near Quebec City. Southern areas from southern Vermont to southern Maine will get into the warm sector, with temperatures surging above 60F (16C) for a brief time.

 

Source: TropicalTidbits

 

 

Source: Climate Prediction Center

 

 

Cool, dry Wednesday, then potential big storm with snow to wintry mix to rain late Thursday into Friday, perhaps last widespread snow of season 

 

The low-pressure system will move out by Wednesday, with another arctic surface high-pressure system pushing in with colder and drier air. But once again, the upper-level ridge to the south will remain strong, while some upper-level troughs and storminess finally reaches the western U.S. after being baked in dryness and record warmth for the past few weeks. One disturbance will be moving eastward through the Plains and U.S. Midwest on Thursday, and eventually reaching our region Thursday night into Friday. With the arctic air able to push a bit farther south this time and still being relatively fresh ahead of the storm, precipitation will likely at least start as snow for most of the region, perhaps except for far southern areas, though this will depend on the exact storm track which has been trending northward lately, perhaps a testament to the strength of the upper-level ridge to the south. This might be one of the few times this cold season in which rich Gulf of Mexico moisture is rammed straight into a fresh cold air mass cold enough for snow, with the surface high-pressure to the north and northeast providing low-level cold air (albeit not as strong as in winter given that it will be April) for the warm, moist Gulf of Mexico air to overrun aloft. There is remarkable agreement (for 4-5 days out) on a scenario like this occurring. As a result, precipitation could be rather heavy, and someone could receive a lot of snow, perhaps one of the biggest of the season. That said, the relatively warm temperatures (warmer than -8C) through a deep layer of the lower-troposphere will not favor ideal dendrite formation and favors riming that leads to lower snow-to-liquid ratios and wetter snow, limiting snow depth. Areas south of a line from Ottawa to Montreal to Bangor, Maine will likely change to ice pellets and then a cold rain by Friday, unless the storm track goes farther south than currently shown. For now, the best chance of a big snowstorm is from central Quebec to northern Maine. This could be the last widespread snowfall of the season for our region.

 

Source: TropicalTidbits

 

 

Warmer with rain next weekend, then cooler but likely lack of arctic cold and more typical April weather pattern with occasional rain chances

 

Another stronger storm will follow closely behind with an almost closed off upper-level low approaching the region next weekend. By this time, the cold air will have become stale, and the strength of the storm combined with is track well north of our region into northern Quebec will likely ensure precipitation will fall as rain for everywhere in our region with warmer air arriving. Cooler and drier air comes in behind the storm, but by this time, the supply of arctic air to the north appears to finally weaken in earnest, and yet the upper-level ridge to the southwest of our region will have weakened. This will reduce the temperature contrast and yield a more typical early-mid spring weather pattern, with mostly mild days and occasional temperature swings and storminess but without the big temperature contrasts, and any snowfall likely being at most sporadic and mostly at higher elevations. 

 

Source: TropicalTidbits