A record-breaking, crippling, multi-day, winter storm will target Eastern Canada over the course of the weekend.
Timeline & Hazards
A strengthening low-pressure system will move across the United States throughout the day on Thursday, bringing a swath of snowfall to portions of Northern Ontario through the afternoon with a mix of rain, snow, and/or freezing drizzle/rain to portions of Southern Ontario in the evening.
Through the overnight hours, persistent snowfall will continue across the northern half of the province as the temperature climbs in Southern Ontario, changing over any wintery precipitation into rainfall. Rainfall warnings have been issued for portions of Eastern Ontario. The rainfall may change over into snowfall throughout the night, primarily for those in higher-elevation regions.
In the morning hours on Friday, a strong cold front will pass through Southern Ontario in a west-to-east direction. The front will enter Ontario sometime in the night between 1 and 5am. The exact time the front enters the province is still unknown. The passage of the cold front will result in a rapid cooldown of the temperatures, dropping as much as 10 degrees in a short few hours. Areas which receive rainfall in the morning will experience a severe flash freeze resulting in icy surfaces and potentially hazardous diving conditions.
After the front passes through, the rainfall will change over into snowfall with strengthening winds. Snowfall will begin to accumulate in these regions rather quickly after the front passes through. This accumulating snowfall will continue for the rest of the day across Southern Ontario. There is the potential for a "dry slot" or a lull in the snowfall activity for areas around the GTA extending into Eastern Ontario, however, models are fairly confident that snowfall will remain a hazard through the afternoon for areas across Southwestern Ontario and near Lake Huron. Total snowfall amounts will range between 5 and 15cm by end-of-day Friday, with the exception of areas near Lake Huron where snowfall amounts could be upwards of 15-30cm, due to the lake enhancement. While the snowfall totals aren't overly high in some regions, the winds will be quickly strengthening throughout the afternoon; reaching between 60 and 90km/h across much of Southwestern Ontario by the afternoon, with gusts closer to 100km/h+ along the shores of Lake Huron and gusts closer to 120km/h+ along the shores of Lake Erie (and Niagara) and the shores of Lake Ontario (towards the eastern end). The combination of these strong winds and any amount of falling snow will result in significant reductions in visibility. This will result in the widespread blizzard and blizzard-like conditions across Southwestern Ontario.
The peak winds will occur in the overnight hours on Friday into Saturday where significant wave heights are likely on Lake Erie and Lake Ontario; potentially exceeding 20 feet. Some models indicate as high as 24 or 28 feet. Alongside the wave heights, the power of the wind will result in a dangerous seiche event on the eastern end of Lake Erie where blizzard conditions, freezing spray, significant wave heights, and major coastal erosion will be taking place.
Moving into Saturday, the system snow will continue across Southwestern Ontario. It should be noted that while the system snow will be lingering through the morning hours on Saturday, the system will be pulling off towards the north, leaving behind lake-effect snow for the traditional snowbelts. As the system pulls away, the winds will start to decrease in intensity, however, winds between 50 and 80km/h are still possible throughout much of the day on Saturday, lasting through to Saturday night. The combination of lake effect snow, which may produce between 15 and 30cm (locally more) by end-of-day Saturday and the still strong winds will continue the blowing snow hazard (blizzard-like conditions) across much of Southwestern Ontario with widespread blizzard conditions in the snowbelts.
Into Sunday, the winds will continue to decrease; reducing to 40 to 60km/h. This will still produce widespread ground drifting and blowing snow with the worst conditions in areas still experiencing snow squalls. Blizzard-like conditions may persist in the early morning hours on Sunday, but the worst of the weather for this event will have passed. It should be noted that it might not be pleasant still on the roads. Widespread blowing snow is still a possibility due to the light nature of the snowfall that will fall.
Summary
Snowfall:
- Widespread 10-20cm of snow in Southern Ontario
- Snowfall amounts may exceed 60cm for areas east of Lake Huron and Georgian Bay
- Snowfall amounts may range between 20 and 40cm for portions of Eastern Ontario extending into Northern Ontario.
- Snowfall amounts may exceed 20cm for places near Fort Erie; some models have over 100cm for portions of Western New York from the lake-effect portion of this event.
Blizzard Conditions:
- Widespread blizzard or blizzard-like conditions through Friday afternoon in Southwestern Ontario
- Blizzard conditions persist through Saturday for areas near Lake Huron, Georgian Bay, and in the Niagara region
- Extensive road closures are likely
Wind:
- Widespread winds between 60 and 90km/h through Friday afternoon and evening
- Wind gusts may approach 100km/h on the Huron shorelines and 130km/h on the Ontario and Erie shorelines.
- Power outages are possible; due to blizzard conditions and road closures in some regions, power outages may be prolonged.
Flash Freeze:
- Icy roads are likely on Friday
Wind Chills:
- As this entire event is ongoing, extreme cold will settle into Southern Ontario. Wind chill values between -20 and -30 are likely on Friday night, Saturday night, and Sunday night with minor relief through the day.
Important Message
This storm is exceptionally strong, potentially becoming a bomb cyclone in which it drops 24mb of pressure within 24-hours. This is a very rare setup for Ontario. For portions of the snowbelts, some of the blizzard conditions experienced may match some of the more prolific blizzards in the 1970s, such as the 1978 blizzard.
This storm should be taken seriously. If you need to travel somewhere this weekend, it is recommended to complete those travels Thursday night or try either on Sunday or Monday. Friday and Saturday, especially in the snow belt regions, will be horrible. Roads will be closed for extended periods of time. Roads may become impassible.
Getting stranded on the roads will be life-threatening. Ensure you have an emergency kit ready.
The OPP are advising people to rethink their travel plans this weekend and to monitor the forecast and weather conditions.
Schools have also started to close ahead of Friday. They can be monitored here.
If anyone had plans to go to the Ottawa Senators-Detroit Red Wings NHL game, it has been cancelled as well. Full announcement here:
