Author: Justin Morrison

Manitoba

Winter Storm to Bring Blizzard Conditions Throughout Thanksgiving Weekend…

A strengthening Colorado Low will bring a long-duration, widespread winter storm to portions of the Upper Midwest in the United States before moving into Manitoba and Northwestern Ontario with blizzard and ice storm conditions.

A band of light to moderate snow will cross Southern and Central Manitoba along a cold front throughout the early morning on Thursday bringing a widespread 2-5cm, locally 10cm of snow. Into the late morning and early afternoon, conditions will begin to deteriorate as a Colorado Low begins to push north towards the region.

Widespread snow is expected across Southern and Central Manitoba extending from the Saskatchewan border into Far Northwestern Ontario. Across the Southeastern Manitoba into Northwestern Ontario, heavy rain will begin to soak the already saturated ground. This will also begin the long-duration ice event which is expected along the Ontario-Manitoba border, east of Winnipeg, extending northeast towards Red Lake and Weagamow Lake in Northwestern Ontario.

The exact location of the system is yet to be determined. Most global forecast models are consistent with the system moving over the Lake of the Woods area, although, a slight shift in the track will make a major change in the forecast in terms of snowfall/rainfall locations, more significantly, the location of the significant ice.

SNOWFALL & BLIZZARD CONDITIONS – SOUTHERN REGIONS

Accumulations from the winter storm will vary greatly throughout Southern Manitoba with the heaviest accumulations throughout the higher terrain. Current guidance suggests snowfall totals will be highest between 30 and 50cm, locally higher towards 65cm+, in the extreme southern portion of Manitoba throughout the Red River Valley into the Darlingford Moraine region. This area has been highlighted with the extent of dark pink in the forecast map. Isolated totals near 70cm may be possible. Snowfall warnings are in effect for portions of this region.

Throughout this region, widespread winds between 60-80km/h are likely to cause significant blowing snow and possibly blizzard conditions. Whether blizzard warnings are issued or not, significant impacts on travel are likely across much of the major highways in the southern portion of the province. Highways such as 1 (Trans Canada Hwy.), 2, 3, 5, 23 and 75 should be avoided throughout the weekend.

The criteria for a blizzard classification and blizzard warning in Canada follow the 4-4-4 rule: 40km/h winds or greater causing widespread reductions in the visibility to 400 meters or less for at least 4 hours. A full list of alert criteria can be found here.

Extending inland towards Lake Manitoba, including Portage la Prairie, snowfall totals will be less in the 20-40cm range although local totals between 40-60cm are possible. The extent of this region can be seen in pink. This region also includes Boissevain to the west and Winkler/Altona to the east. This region continues in a swath between Lake Manitoba and Lake Winnipeg, extending just east of the lake as well, including Bloodvein. This region is less likely to see the locally higher totals. Snowfall ratios in this region will likely peak around 10:1 (10 inches of snow for 1 inch of water).

Extending out in all direction, snowfall totals are likely to decrease. This is seen in the dark blue shade on the map. Towards the west of Lake Manitoba, snowfall totals between 10-20cm are likely. There was some discussion within the team as to whether or not we should extend this region to the west of Northern Lake Winnipeg, although, we have went against this due to the expected location and size of the system. This remains a possible option, but, less likely at this time. Between Southern Lake Winnipegosis and Lake Winnipeg, 10-20cm of snow is also possible. Towards the east, including Winnipeg, as well as areas east of Lake Winnipeg to the Ontario border, snowfall totals between 10-20cm are likely throughout the weekend with local totals towards 30cm. Finally, areas northeast of Lake Winnipeg through the Poplar region towards the God’s Lake region will also see between 10-20cm of snow with an increased risk of 20-30cm.

Towards the west into Saskatchewan, a brief period of snow is likely to bring generally 5cm of snow to the region. Further into Manitoba, 5-10cm is expected from the ‘after side’ of this system. In Ontario and Southeastern Manitoba, 5-10cm is likely with most, if not all, the snow remaining melt-on-contact due to the expected heavy rainfall throughout the system. Towards Lake Superior, snowfall totals will be localized to 5cm with limited to no visible accumulations likely.


Projected snowfall totals between Thursday, October 10th to Sunday, October 13th

SNOWFALL & BLIZZARD CONDITIONS – NORTHERN REGIONS

Accumulations from the winter storm will be significant along the Manitoba/Ontario border. The heaviest accumulations will occur in the pink region. This region extends from between Poplar Park Reserve in Manitoba and Opasquia Park in Ontario along the border to Sturgeon Lake in Ontario. Snowfall totals between 25-45cm are likely with local amounts approaching or surpassing 50cm. Outside of this region, a widespread 10-20cm, locally 25cm is likely within the dark blue region. This extends from Lake Winnipeg through to Sandy Lake and Sachigo Lake in Ontario towards Hudson Bay. with the heaviest accumulations throughout the higher terrain. A winter storm warning is in effect for portions of this region.

In the light blue region, which extends from Hudson Bay through to Lake Winnipeg and Big Trout Lake, Ontario, snowfall totals between 5-10cm are possible. Local totals towards 15cm are possible into Manitoba, although, current guidance suggests this is unlikely.


Projected snowfall totals between Thursday, October 10th to Sunday, October 13th

ICE STORM

Across Southeastern Manitoba, southeast of Winnipeg, extending into Northwestern Ontario along the Manitoba/Ontario border, a long-duration ice storm is increasingly likely.

As temperatures near 0 C throughout the long-duration of the winter storm, freezing rain and ice pellets will be a large concern along the border of the provinces towards the south. With the system expected to track of Lake of the Woods, heavy rain is likely across portions of Southeastern Manitoba (Buffalo Point westward) and much of Northwestern Ontario. A thin band of moderate to heavy freezing rain is likely to remain stationary for multiple hours.

Extending from the Vita/Marchand area in Manitoba through the Ontario border into the Red Lake and MacDowell Lake areas, heavy freezing rain between 15-30mm of ice is possible. In a tight gradient outside of this region, the freezing rain totals will quickly drop off in a thin 5-15mm ice range followed by a large 2-5mm ice range. This larger area extends from Hudson Bay through Big Trout Lake into the Whiteshell Provincial Park area in Manitoba. The attached map highlights the possibly affected areas, but due to the tight gradient, we have not added totals onto the map.

Widespread wind gusts between 40-60km/h, locally higher towards Southern Manitoba will likely result in widespread power outages in the affected communities. Highways such as 1 /17 (Trans Canada Hwy.), 44, 105, 307, 596, 658 should be avoided throughout the weekend.


Projected freezing rain totals between Wednesday (pm), October 9th to Sunday, October 13th

RAINFALL

Across Northwestern Ontario and Southeastern Manitoba, heavy rain will bring a wide swath of 40-70mm to the region. Local totals between 70-90mm will be possible in the strongest bands in the system. Rainfall warnings have been issued for these regions as there are numerous communities already dealing with flooding throughout the area.

You can continue to monitor weather alerts issued by Environment Canada from their website: https://weather.gc.ca/warnings/index_e.html

Alberta

Long-Duration Snowstorm Brings Early Season Chill Across British Columbia…

A strengthening Colorado Low will bring a long-duration, widespread snowstorm to portions of British Columbia, Alberta, and Saskatchewan before lingering into Manitoba and Northern Ontario.

A weak low is expected to bring a snowstorm to the mountains of British Columbia and Alberta on Friday lasting through to Sunday. Strengthening into the weekend, on Saturday, a strong low is expected to form near the Wyoming/Colorado border before moving east towards Northwestern Ontario before phasing out and reorganizing into a low which will bring widespread rain to portions of Northeastern and Southern Ontario.

WESTERN PRAIRIES & SOUTHERN BRITISH COLUMBIA SNOWFALL TOTALS

Accumulations from the snowstorm will vary greatly throughout Southern Alberta/Saskatchewan with the heaviest accumulations throughout the mountains. Current guidance suggests snowfall totals will be highest between 30 and 60cm, locally higher towards 70cm+, in the extreme southwestern portion of Alberta throughout Waterton Lakes National Park towards Pincher Creek, where the extent of red is shaded in the forecast map. Isolated totals near 100cm may be possible. Along the United States border extending into the mountains, highlighted in pink, snowfall totals between 15 and 30cm are likely with pockets of snow towards 40cm possible throughout the mountains. The highest snowfall totals are due to the position of the low creating an ‘up-sloping’ event where the snow is driven up and into the mountains and foothills allowing for significant accumulations. Snowfall ratios in this region will likely peak around 10:1 (10 inches of snow for 1 inch of water).

Down the mountains into the foothills and into the Central-Northern Rocky Mountains, Purcell Mountains, and Northern Selkirks Mountains, snowfall totals will be limited to 10-20cm with local totals towards 20-30cm. This includes Banff and Cranbrook, as well as, this region is highlighted in purple on the forecast map. In Extreme Southern Alberta, outside of the foothills will likely see between 10-20cm of snow. This includes the City of Lethbridge extending towards the southeast, also seen in purple on the forecast map. The snowfall totals may significantly drop off outside of the mountains and foothill regions as temperatures on Saturday through to Monday across the lower Prairie regions will be within 2 degrees of 0, meaning, snow may change over to rain at the lower elevations. This would significantly limit accumulations. The temperature change would be most prevalent in Extreme Southeastern Alberta into Southern Saskatchewan. Snowfall totals in this region are expected to be between 5-15cm are likely, which can be seen in purple on the forecast map, and circled. If temperatures trend cooler for this region, 10-20cm wouldn’t be out of the question for Southern Alberta and Southwestern Saskatchewan, extending as far in to include Shaunavon. Snowfall ratios will peak around the 3:1 and 5:1 range.

A general 5-15cm, locally up to 25cm, can be extended throughout the Rocky Mountains from the Lake Lousie region northwest into British Columbia extending towards Fort Nelson, as well as the Southern Selkirks Mountains and portions of the Monashees and Cascade Mountains. This would include Jasper and Grande Cache. This is highlighted in dark blue on the map. Across Southern Alberta and Southwestern Saskatchewan, a widespread 5-10cm, locally 15-20cm can be expected, also highlighted in dark blue. This includes Calgary, Medicine Hat, Swift Current, Rockglen, and Penticton. Elsewhere in light blue, flurries are likely. Snowfall totals around 5cm with local totals to 10-15cm are likely around Kelowna and Vernon. Snowfall totals will range under 5cm with local pockets sticking up to 10cm for portions of Saskatchewan and Central Alberta. Generally, the snow will melt-on-contact for a majority of the event for these highlighted regions, including Red Deer, Regina, and Saskatoon.

Environment Canada has issued widespread special weather statements across Southern, Western and Central Alberta, as well as, portions of British Columbia. Winter storm watches have been issued ahead of the snowstorm for Pincher Creek, Waterton Lakes National Park, Canmore, Okotoks, Cardston, and Fort Macleod regions.

Weather alerts can be monitored on Environment Canada’s website: https://weather.gc.ca/warnings/index_e.html

Projected snowfall totals between Friday, September 27th to Monday, September 30th

MANITOBA & ONTARIO SNOWFALL TOTALS

As the snowstorm producing low-pressure system crosses east, bringing the precipitation with it, light to moderate showers are likely across Southern Manitoba, and most of Northern Ontario. Alongside these showers, a band of flurries to light snow will cross portions of Central/Northern Manitoba into Far Northern Ontario. Snowfall totals less than or near 5cm are likely due to the snow mainly being melt-on-contact. A few pockets across Southwestern Manitoba and into Far Northern Ontario may see local totals towards 10cm. The highest confidence for locally higher totals is circled in red.

Projected snowfall totals between Monday, September 30th to Wednesday, October 2nd

BLOWING SNOW & STRONG WINDS

As the snow falls across the Southern Prairies, increasing wind speeds will bring the threat for hazardous traveling conditions in fast accumulating snow and falling snow. Current guidance suggests wind speeds will range from 30-50km/h across Southern Alberta and Southern Saskatchewan later in the day on Saturday extending through to Sunday morning. During the afternoon and evening on Sunday, winds will likely increase to 40-70km/h before 40-60km/h wind gusts settle in across Saskatchewan, Manitoba, and Ontario as the system weakens and phases out beginning mid-day Monday.

Blizzard conditions are possible.

Blowing snow and falling snow may make travel hazardous on Highway 1, 2, 3, and 4 across Southern Alberta and on Highway 1, 13, 18, 21, and 37 in Southern Saskatchewan.