Friday, December 12, 2008

Major winter storm to affect southern Prairies/northern Plains this weekend..

A strong storm system pushing into southern BC today will cross into Montana Saturday before merging with a central Plains storm system Saturday night. This Alberta clipper/Colorado low hybrid storm will then push up through Minnesota on Sunday bringing strong northerly winds, snow and blowing snow, and bitterly cold temperatures to the Dakotas and parts of southern MB, especially Saturday night into Sunday. The result will be a major winter storm for the northern Plains and much of the southern Prairies along the US border, with blizzard conditions possible in many areas including the Red River valley. A winter storm watch has been issued for the Red River valley in MB with blizzard watches across all of North Dakota and NW Minnesota. For North Dakota information on this storm, consult their winter storm page.

Models continue to show Winnipeg will on the northern edge of the heaviest snow from this system with the bulk of the snow (15-25 cm or more) falling through the Dakotas and northern Minnesota into NW Ontario. Remember though, with storms like this, it's not the total amount of snow that's the problem.. it's the wind in combination with falling snow that creates the problems with blowing and drifting. So it's important not to focus solely on the snow amounts with this system (although that will certainly be a factor), but rather the winds, poor visibilities and extreme windchills.

Winds will be increasing by Saturday evening across southern MB with snow and strong winds continuing Saturday night through Sunday. As a result, there will be extensive blowing and drifting snow Sunday especially through the Red River valley and open areas along the US border with blizzard conditions possible. The Hwy 75 corridor will likely be very bad especially from south of Winnipeg down to Emerson where blizzard conditions are possible Sunday. Travel into the States this weekend is not advised due to this dangerous storm which will likely be shutting down highways across the Dakotas, and possibly parts of southern MB as well. Add to that bone-chilling wind chills of -40 or lower, and you have yourselves a serious winter storm. Get ready folks, this will make for an interesting end to the weekend..


  1. Looks like they also added Portage La Prairie region to the Winter storm watch area.
    you know the stretch between Winnipeg and Portage is well know for it's whiteout conditions!

  2. Blizzard warnings have been issued for the southern Red River valley including Emerson and Steinbach, as well as all of North Dakota and western MN. Look for blizzard conditions to develop tonight in these areas and continue into Sunday. Last night's model runs have trended a little further south with this storm system with
    the bulk of the heaviest snow (15-25 cm) expected south of the international border, and 5-10 cm expected over southern MB mainly south of the TransCanada. Here in Winnipeg, about 5 cm of snow is expected tonight into Sunday, with blowing snow and poor visibilities especially in open areas outside the city. Remember, even minor amounts of snow can cause problems with blowing and drifting if winds are strong enough.

    Extreme windchills of -40 to -45 will be an issue for everyone overnight through Sunday and into the new week, with very cold temperatures of -25C to -35C through the period.

  3. Rob I don't understand the winter storm warning for Porage -Carman areas!
    They say "heavy snow" in the warning page except 2-4 cm is only expected!
    Do you think blizzard like conditions are possible as opposed to the heavy snow!

  4. The winter storm warning for the Portage-Carman region is likely based on expected near-blizzard like visibilities tonight into Sunday along with wind chills, rather than on the snow amounts. The worst conditions are expected further south in the Red River valley where blizzard warnings are in effect.

    Latest model runs continue to show a more southern drift on this storm system with even less snow expected now over southern MB.. the worst of this storm will definitely be south of the border in ND. The way the models are trending, we may get only a dusting of snow in Winnipeg which would greatly diminish the blowing and drifting snow issue here. We'll see how the system develops in reality, but right now.. it's looking less ominous for southern MB than yesterday's runs..

  5. Extremely sharp baroclinic zone associated with this system:

    Winnipeg: -22 C
    Grand Forks: -16 C
    Fargo: -7 C
    Twin Cities: 4 C (!!)

    We appear to be too deeply embedded in the cold dry air consistent with the southward trend seen in the models.

    Extreme cold spilling down with high temps in N Battleford this afternoon around -29 C. Gulp... with all the fresh, deeper snow cover around we are going to see some real mind numbing values. Time to visit Cuba.

  6. NWS is still giving South-Eastern Manitoba a moderate chance of more than 10cm of snow for tomorrow. I am not looking forward to -50 wind chills, as per the latest EC forecast.