Freezing Rain Threatens Icy Sunday Across Saskatchewan & Manitoba

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What previously looked like a possible widespread ice event, according to weather models, has luckily down-scaled and will now only impact a narrow track across parts of Saskatchewan and Manitoba.

A disorganized system will cross into Southeast Saskatchewan from Montana after midnight tonight, travelling northeastward and reaching Manitoba shortly before sunrise. This system will only bring a narrow band of precipitation to the region, but due to the presence of warm air aloft and below freezing temperatures at the surface, this precipitation will fall as freezing rain. The freezing rain will be light and last for several hours, resulting in ice accretion amounts up to 5mm.

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Temperature Profiles and Precipitation Types

By around the lunch hour, the freezing rain will start to taper off and transition over to snow. As the entire system pushes eastward, Southern Manitoba will also start to see some snow moving in from North Dakota Sunday afternoon. The system will become more organized throughout the evening and overnight, leading to the development of additional snow in Central and parts of Northern Manitoba. There is still some uncertainty regarding exact snowfall amounts, but it looks like the southern half of the province can expect 5-15cm of fresh snow by the end of Monday.

Rapidly Strengthening Bomb Cyclone Expected to Bring Heavy Rain and Wicked Winds to the Maritimes

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Hang on to your umbrellas! We have an incoming bomb cyclone that is set to not only drench the Maritimes, but bring some intense winds to the region as well. A bomb cyclone is a storm that undergoes rapid intensification, called bombogenesis, that results in a drop in central pressure of at least 24mb over a 24 hour period. A system has begun travelling northward along the American Atlantic Coast and the further north it travels, the stronger it is expected to become under this rapid intensification.

The storm will bring precipitation to the Maritimes in two rounds. It will start off with warm, moisture-laden air being funnelled up from the Gulf along the warm front, leading to temperatures climbing into the double digits. Following a break in the precipitation from the first round, the length of which will be dependent on the distance from the centre of the storm, a second round of rain will move in along the cold front. Behind this cold front, temperatures are expected plummet and will fall below 0°C across New Brunswick, leading to the risk of a flash freeze. Combined, these two rounds of rain will bring a widespread 10-50mm of rain across most of the Maritimes.

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New Brunswick

Things in New Brunswick will certainly get messy over the coming days due to this incoming storm. The first wave of precipitation will move into Western New Brunswick around sunrise Wednesday morning. The temperatures will rise with the arrival of the warm front and rain, but there will still be some isolated pockets of cold air near the surface that could persist for several hours, leading to freezing rain. Luckily any ice accretion will quickly melt as temperatures rise.

The rain will continue throughout most of the day and it will start to taper off, from south to north beginning in the evening. Due to its proximity to the centre of the storm, there won’t be a break between to the rounds of precipitation in Northwest New Brunswick. As a result, this is where the highest rainfall amounts of close to 50mm are expected. The rest of the province will start to see this second wave move in from the west overnight. It will lose intensity as it pushes eastward and the heaviest rain will fall over the western half of the province, where 25-50mm of rain is expected overall with the storm and only 10-25mm to the east. This second round won’t last long and will exit the province by the late morning.

There will be a unique problem in New Brunswick that the rest of the Maritimes won’t have to worry about. Some parts of the province have a considerable snowpack over 30cm which will end up melting with temperatures rising into the double digits through the day Wednesday. However, when combined with the amount of incoming precipitation and the ground likely remaining at least partially frozen, standing water and flooding becomes a concern. To make matters worse, the temperatures will drop drastically across most of the province overnight Thursday, to well below the freezing mark, which could lead to a widespread flash freeze.

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Nova Scotia

The scenario across Nova Scotia with this storm will be a little less complicated, in regards to precipitation. The first wave of rain will make its way into Western Nova Scotia in the mid to late morning Wednesday. The rain will be heavy at times across the western half of the Mainland and it will then dissipate across the province through the evening. The second round of rain will then arrive early Thursday morning and is only expected to last 4 hours or so as it crosses the province, before the storm finally makes its way out of the region in the evening. Most of Mainland Nova Scotia and along the South Coast of Cape Breton Island can expect 10-25mm of rain while the rest of the province will see 5-10mm

Prince Edward Island

Prince Edward Island, much like Nova Scotia, has a fairly straightforward forecast with this storm. The first wave of rain will impact the Island starting early Wednesday afternoon and continuing into the evening. Then, the second wave will move in after sunrise on Thursday and cross the Island in the span of 3-4 hours. Rainfall amounts of 10-25mm are likely in Prince and the western half of Queens County and 5-10mm in Kings County and the eastern half of Queens County.

Strong winds will also be a factor with the incoming bomb cyclone. In this model image showing 1:00 AM Thursday, we can get a good look at both the size and structure of the storm, along with the precipitation types and their intensities. What we also see is the projected internal pressure of the storm, in millibars, as well as the lines of equal pressure, in black, known as isobars. Winds are driven by air moving from areas of high pressure to those of low pressure and when isobars are really close in strong storms, as seen in this case, we know that the winds will be quite strong.

The strong winds will start making their way into the Maritimes Wednesday evening and they will peak overnight. The entire region will get hit by sustained winds above 40km/h and gusts over 70km/h, but Western Nova Scotia and Southwest New Brunswick in particular will be hammered by gusts in excess of 100km/h. These will be onshore winds so pounding surf and some coastal flooding are very likely along the Atlantic Coast of Nova Scotia and along the Fundy Coast to the west of St. John starting late Wednesday and continuing through Thursday morning.

Prolonged Freezing Rain Threatens Icy Start to Week for Parts of Southern Ontario on Monday

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December has kicked off with a cold and snowy start across Southern Ontario, as a significant lake-effect snow squall outbreak blanketed parts of the snowbelt over the past week. This wintry weather was accompanied by the season's first blast of Arctic air, bringing wind chills as low as -20°C.

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However, a shift in the weather pattern is underway, with milder conditions already spreading into Southwestern Ontario, where Sunday saw daytime highs climbing into the mid to upper single digits.

A weather system is expected to arrive early Monday, bringing warmer air aloft, while near-surface temperatures hover around freezing. This setup creates ideal conditions for freezing rain across parts of Central and Eastern Ontario, which, according to the latest data, could last for an extended period.

Freezing rain is expected to begin in the morning hours on Monday, persisting through the afternoon and into the evening. This prolonged event could result in a thin but hazardous layer of ice forming on untreated surfaces such as roads, sidewalks, trees, and power lines, with localized power outages a possibility.

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

The initial bands of precipitation will move into Deep Southwestern Ontario, including Windsor and London, during the pre-dawn hours on Monday. Temperatures in this region will remain several degrees above freezing throughout the day, so precipitation here is expected to fall as rain.

As the system progresses north and east during the morning, it will encounter below-freezing temperatures near the surface in areas like the Dundalk Highlands (including Orangeville and Shelburne) and parts of the Greater Toronto Area (GTA).

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This will result in the development of freezing rain, creating a zone stretching from Orangeville eastward through York Region, along the higher elevations of the Oak Ridges Moraine, and into southern portions of Central and Eastern Ontario.

This band of freezing rain is expected to persist into the early afternoon, with locations such as Barrie, Orillia, Kawartha Lakes, Peterborough, and Belleville likely experiencing the heaviest impacts.

Further north, areas like Muskoka, Bancroft, and the Ottawa Valley are expected to see a mix of wet snow, ice pellets, and freezing rain beginning early Monday afternoon. While significant snowfall accumulation is not expected for Southern Ontario, enough snow could fall to create slushy and slippery road conditions in these areas.

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

Freezing rain will begin to taper off in the south later in the afternoon, though freezing drizzle may linger into the early evening. Temperatures are forecast to rise slowly above freezing later in the evening and overnight, which should help melt any accumulated ice, albeit gradually.

In more northern portions of Central and Eastern Ontario, heavier freezing rain will persist into Monday evening before ending overnight. However, freezing drizzle may continue in the Ottawa Valley into early Tuesday morning, potentially causing icy conditions for the Tuesday morning commute.

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The most significant freezing rain impacts are expected in a narrow corridor extending around Lake Simcoe and eastward along the Lake Ontario shoreline.

Ice accretion of 2 to 5mm is possible in areas such as Orangeville, Newmarket, Collingwood, Barrie, Orillia, Midland, Bracebridge, Lindsay, Peterborough, Oshawa, Belleville, and Kingston.

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For the rest of Central and Eastern Ontario, including the Ottawa Valley, up to 2mm of ice accretion is expected, accompanied by ice pellets and a few centimeters of wet snow.

In the GTA, the greatest impacts from freezing rain will likely occur in the northern and eastern portions of the region. Toronto may experience brief freezing rain during the morning hours, but it is expected to transition quickly to rain, especially closer to the lakeshore.

Steep Drop in Temperatures Will Lead to Flash Freeze Risk This Evening and Freezing Rain Into Wednesday

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It’s been a bit of a weather roller coaster across Southern and Central Alberta over the past several days, with snow and frigid Arctic air late last week to single digit temperatures, melting snow and even some rain falling in the Northern Rockies.

Now, temperatures are expected to plummet later this evening, leading to a risk for a flash freeze along with freezing rain across a swath of the province continuing throughout the day tomorrow.

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Warm temperatures across Central and Southern Alberta in the single digits have resulted in the melting of some of the existing snowpack. On top of this, precipitation has already begun to push into the Northern Rockies region of Alberta from British Columbia as a mix of rain and snow this afternoon.

As the precipitation pushes deeper into the province and temperatures quickly fall to just below the freezing mark this evening, not only will the melted snow and slush rapidly freeze, the rain will also transition over to freezing rain, creating very icy conditions. This patch of freezing rain will remain fairly stationary around Grande Prairie into Wednesday morning, leading to ice accretions up to 5mm. At this point, the entire system will begin to push southeastward across the province, bringing light freezing rain along a narrow track throughout the day, adding to the already icy conditions expected from the flash freeze.

To the north of this freezing rain, where temperatures will be slightly cooler, light snow is expected to fall. Snowfall accumulations will also be limited with this system and a widespread 5-10cm is expected.

Winter Roars Into Ontario This Week With Freezing Rain Threat; Snow Squalls Could Dump Up to 50cm of Snow

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While winter has gotten off to a slow start across Southern Ontario, with many areas only seeing their first snowfall within the past week or two, it seems that change is on the way. November is shaping up to go out like a lion, as Mother Nature makes up for lost time.

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A significant pattern shift is expected to bring the threat of freezing rain late Monday across Central and Eastern Ontario. This will be followed by multiple weaker systems across the Great Lakes region and colder air flooding into the province.

That colder air will set the stage for what could become our first major snow squall event later this week and into the weekend. In some typical snowbelt areas, snowfall could be measured in feet (30+ cm) by this time next week!

Let’s break down what is shaping up to be a very dynamic and active forecast over the next five to seven days, starting with the freezing rain threat.

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Freezing Rain Risk: Monday into Tuesday

PRECIPITATION TYPE - MAP FROM WEATHERBELL

A system is expected to move into Southwestern Ontario and the Golden Horseshoe beginning Monday afternoon. With temperatures forecasted to stay well above freezing in these areas, precipitation will fall as rain.

However, as the system moves northeast into Central and Eastern Ontario after midnight, it will encounter a stubborn layer of colder air near the surface. Temperatures hovering near or just below freezing may allow some of the rain to fall as freezing rain overnight into early Tuesday morning.

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There remains some uncertainty about how widespread this pocket of cold air will be. Higher-elevation areas of Central and Eastern Ontario, including Bancroft, Barry’s Bay, and Algonquin Park, are most likely to experience freezing rain. It’s also possible for freezing rain to extend westward to Muskoka and Parry Sound, and eastward into the Ottawa Valley, including the City of Ottawa.

For Bancroft, Barry’s Bay, and Algonquin Park, ice accretion totals could reach 2-4 mm by Tuesday morning, though any ice will quickly melt after sunrise as temperatures rise above freezing by late morning. In Muskoka and the Ottawa Valley, a thin layer of ice on untreated surfaces is possible, which could make for a slow Tuesday morning commute. There is a slight chance of school bus cancellations in affected areas.

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Northern Ontario: Heavy Snowfall Ahead

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Northern Ontario will experience heavy snow from this same system, as colder air dominates in the region. Light to moderate snowfall is expected to begin in Northwestern Ontario by early Monday afternoon, gradually spreading eastward into the evening and overnight.

Snow will continue across Northern Ontario throughout Tuesday, with the heaviest snowfall expected near the Quebec border in Northeastern Ontario. Snowfall will gradually ease later on Tuesday and into early Wednesday but could persist near James Bay in a zone extending from Hearst to Lansdowne House.

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Over three days, snowfall totals will generally range from 10 to 20 cm across Northern Ontario. Far Northern Ontario near James Bay could see totals exceeding 20 cm by Thursday, while lake-enhanced snowfall southeast of Lake Superior, including Sault Ste. Marie, could push totals closer to 30 cm.

Thunder Bay is expected to see slightly less snow, as the city may end up in a drier part of the system. Forecasts currently suggest snowfall amounts of 5 to 10 cm in this area.

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Southern Ontario: Cold Air and Lake Effect Snow

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As the system moves out of Southern Ontario late Tuesday, a surge of cold air will follow in its wake. This will briefly activate the lake effect snow machine around Lake Huron and Georgian Bay beginning Tuesday evening and lasting into Wednesday.

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At this time, temperatures are expected to hover near the freezing mark, which could limit significant accumulation. The most likely target zone for this initial burst of lake effect snow includes areas east of Georgian Bay, such as Parry Sound, Huntsville, and Bracebridge. These areas could see 10-15 cm, with localized amounts of up to 20 cm by the time snow bands taper off Wednesday evening.

For higher elevations southeast of Owen Sound, including Hanover, Markdale, Shelburne, and Orangeville, up to 5-10 cm of snow is possible, as cooler temperatures in these areas will allow snow to accumulate more easily. Surrounding regions, including parts of the Greater Toronto Area, may see just a few light flurries.

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End of the Week: A Snow Squall Event Looms

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Lake effect snow will temporarily pause as another system slides through the Great Lakes region. However, this system appears to stay largely south of the border, bringing only a few flurries or light showers to areas near Lake Erie and the Golden Horseshoe early Thursday.

As we approach the weekend, Southern Ontario will see its coldest air of the season so far, with overnight lows plunging to several degrees below freezing across much of the province.

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A dominant westerly to northwesterly wind is expected to develop Friday and persist into the weekend. This setup will create ideal conditions for intense snow squalls off Lake Huron, Lake Superior, and Georgian Bay starting Friday afternoon and lasting through the weekend.

These snow squalls could bring significant snowfall totals, blowing snow, and near-zero visibility to localized areas in the snowbelt. Travel could become difficult or even dangerous in the hardest-hit regions.

Based on the current forecasted wind direction, regions including Kincardine, Owen Sound, Hanover, Midland, Oro, Orillia, and Gravenhurst are likely to see the heaviest impacts. This also extends up into Northern Ontario around the Lake Superior shoreline with Sault Ste. Marie in the bullseye. Some locations within this zone could receive up to 50 cm of snow by the end of the weekend.

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Snow Squall Uncertainty

It’s important to note that snow squalls are highly localized events, and not everyone will experience intense snowfall totals. One area may receive significant snow accumulations, while locations just a few kilometres away might see only a dusting.

Confidence is high that some sort of snow squall event will occur, but exact locations will depend on the finer details of wind direction and temperatures.

CREDIT: Environment CANADA

Environment Canada has also mentioned the potential for significant snow squalls later this week:

The first significant lake effect snow of the season is likely beginning Friday. This has the potential to be a highly disruptive and prolonged event for areas near Lake Huron, Georgian Bay and eastern Lake Superior. While confidence is medium to high that lake effect snow and blowing snow will occur, confidence in exact locations to be affected as well as snowfall accumulations is low. As is normally the case in these situations, snowfall amounts will be highly variable. Some areas may see well in excess of 50 cm by the end of the weekend. - Environment Canada

Stay tuned for updated forecasts in the coming days as higher-resolution models provide more details. We’ll refine the snow squall forecast and pinpoint areas most at risk.

Retrograding Storm Will Bring a Freezing Rain Threat To New Brunswick Friday

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It’s been an extended wet stretch through the Maritimes lately and that pattern is set to continue over the next couple of days. A low pressure system that has been bringing heavy rain and strong winds to Newfoundland has begun to retrograde and travel westward towards the Maritimes, where it is expected to bring even more rain to the already soggy region starting later tonight.

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Most of the Maritimes can expect steady rain, that could be heavy at times, throughout the day Friday and into Saturday, with a widespread 5-30mm falling across the region and up to 50mm possible in the Cape Breton Highlands.

The leading edge of this storm, however, will encounter cool air over land in New Brunswick, with temperatures hovering around 0°C or just below, resulting in freezing rain falling for up to several hours. The freezing rain will begin in the early morning hours and gradually spread westward throughout the morning. As temperatures climb throughout the day, the freezing rain will transition to rain, but surfaces will still be quite slick with a thin layer of ice.

Up to 2mm of ice accretion can be expected across most of the province and closer to 4mm could be seen in the northwest where the cooler air will persist, leading to 4-6 hours of freezing rain. Areas along the eastern coast look like they will be spared from the freezing rain since temperatures are expected to stay a few degrees above freezing overnight. Make sure to take extra caution when travelling along icy roads and sidewalks tomorrow morning.