Updated: Oct 22
Friday Oct 23rd to Saturday Oct 24th, 2020
Threat level: MODERATE
Impacts: LOW (based on population density)
Confidence: HIGH (based on model agreements)
Expected hazards: SNOW SQUALLS
Expected snowfall: 15-25cm, with locally higher amounts
Time frame: starting Friday morning, intensifying into the evening and overnight, and lightning to flurries by Saturday evening. Flurries will remain possible on Sunday
Locations impacted: Berens River and Poplar National Park Region in Manitoba
Expected watch: snow squall watches/warnings (localized)
Most likely areas impacted: Areas southeast of Lake Winnipeg
Discussion: After digging out from over 45cm of snow last weekend, Berens River looks to have another blast of lake-effect snowfall ahead this weekend. A Colorado Low will pass to the south of the region Thursday, bringing northwesterly winds on the backside, which will usher down another wave of cold air from the Arctic. Winds will change and align to the northwest, combining with 850mb temperatures of around -10C occurring over the 7C to 8C degree waters of Lake Winnipeg.
This will set up a period of 24-48hrs from Friday morning to Saturday evening where heavy snow could occur around Berens River and the Poplar National Park region. At this time, the heaviest snowfalls look to be Friday evening. The snow should lighten late Saturday, though a few flurries look possible Sunday. Winds should slowly die down afterwards bringing and end to the snow. General amounts of 15-25cm look possible for the region with local amounts around 30cm or more possible in the heaviest snows.
From the Prairie and Arctic Storm Prediction Centre at 2pm Wednesday:
THE AB SHORTWAVE TROUGH WILL ALSO SPREAD SOME LIGHT SNOW ACROSS SOUTHERN MANITOBA ON THURSDAY ALTHOUGH ACCUMULATIONS WILL BE MINIMAL AS THE MAIN ENERGY WILL BE FOCUSSED IN THE DAKOTAS. ON THE BACKSIDE OF THIS SYSTEM, A NORTHWESTERLY FLOW WILL SET UP ONCE AGAIN, SO AREAS IN THE LEE OF LAKE WINNIPEG WILL SEE LOCALIZED HEAVY SNOW IN LAKE EFFECT SNOW SQUALLS. THE BERENS RIVER REGION MAY SEE SIGNIFICANT SNOWFALL AGAIN ON THURSDAY NIGHT INTO FRIDAY.
4:22 AM CDT Thursday 22 October 2020 Snow squall watch in effect for:
Little Grand Rapids and Atikaki Prov. Park
Snow squalls are expected to develop. Under the snow squall bands, visibilities will be significantly reduced due to the heavy snow, and snow will quickly accumulate. A cold airmass combined with northwest winds off the warm waters of Lake Winnipeg will create a favourable setup for snow squalls beginning Thursday afternoon. Snow amounts will be highly localized but may exceed 20 to 30 cm in some areas by the time the snow squalls diminish on Saturday as the wind shifts to a more northerly direction. This snow squall watch may be upgraded to a snow squall warning as the event nears and the areas impacted by the heaviest bands of snow become more clear. Travel may be hazardous due to sudden changes in the weather. Visibility may be suddenly reduced at times in heavy snow. Snow squall watches are issued when conditions are favourable for the formation of bands of snow that could produce intense accumulating snow or near zero visibilities.