Wednesday, January 09, 2013

Colorado low to impact southern MB Friday into Saturday with snow, strong winds, sharply colder temperatures..

GGEM model valid Friday evening
showing Colorado low tracking
into Minnesota. Strong north
winds over southern MB will give
widespread snow and blowing snow
Heads up folks..  a Colorado low storm system is heading up into Minnesota by Friday night, which will mean winter storm conditions likely moving into southern MB during the day Friday with strong winds and blizzard conditions possible over the RRV by Friday night. In advance of the storm system, a southerly flow of unseasonably mild air will push temperatures above the freezing mark Thursday over southern Manitoba with highs of +2C in the RRV to +5C over SE Manitoba.  That will be the last of the mild air for awhile however as a strong cold front pushes through southern Manitoba Thursday night, shifting winds into the north and tapping much colder air from the Arctic. Snow will develop overnight Thursday behind the front and continue into Friday, with strengthening winds and falling temperatures through the day.  Snow is expected to intensify by Friday evening as the main Colorado low storm system tracks into Minnesota, bringing a large swath of snow over the RRV and southern MB (see image showing storm position at 6 pm Friday evening). North winds gusting to 70 km/h will combine with the falling snow to produce considerable blowing and drifting snow, with very poor visibilities and possible blizzard conditions at times, especially in the Red River valley. Travel will not be advised across many highways and motorists should be prepared for possible road closures by Friday night.  The storm will continue into early Saturday morning before it gradually tapers off by midday as the storm tracks into NW Ontario. Much colder air will follow in the wake of this storm system, with temperatures in the -20s through the weekend into next week.

Probability of 20 cm or more of  snow
from HPC NOAA. Light blue area
denotes >50% chance of 20 cm+
Total snowfall amounts from this storm system are expected to be in the 10-20 cm range over the RRV with 20-30 cm possible in some areas south and east of Winnipeg into NW Ontario. The strong winds will also mean heavy drifting as well which will hamper snow clearing operations. This storm system will also be affecting a large part of North Dakota, northern Minnesota and NW Ontario Friday into Saturday, so be prepared for delays or road closures if you have travel plans to those areas Friday or Saturday.  Stay tuned on this developing winter storm, as I will have frequent updates on the evolution of this storm as it develops.   Also, take part in Rob's Obs snow poll (top right) to give your best guess as to how much snow Winnipeg will see from this system. 

Snow poll results: Actual snowfall was 13 cm (as measured at my site) 74 poll responses. Most popular reply was 15-20 cm (34 respondents) followed by 10-15 cm (17 replies)  "Ensemble" poll average was 15.3 cm             


  1. Thanks rob for all of your great current updates do you have any ideas on how intense the storm will be and what kind of snow southwestern Manitoba should expect in the Brandon area any thoughts would be great!

  2. Rob, can't thank you enough for your forecasting skills and the service you provide our community. To the extent you are able to arm us with information we can use to make/alter plans really is a great service. Much appreciated and many thanks.

  3. Overall, I think Brandon and SW MB are in line for a good 10-15 cm Friday into Friday night, with 20-25 cm possible under some heavier bands, and also along upslope areas of the Turtle and Riding Mtns. Those estimates are based on current model guidance.. things could change over the next day or so, but that should give you a general idea of what to expect..

  4. Hey Rob, thanks for all the updates today. I just saw The Weather Networks forecast which are predicting only 5-10cm of snowfall for Winnipeg on Friday, do you think they are underplaying this storm?

  5. Mark..

    Appreciate the kind words. I run this blog mainly to give a lot more insight into forecasts that are often too vague or lack information, or just general weather talk. I'm happy that people find value in that..

    I also appreciate everyone's input and contributions on the blog as well that make this forum a more valuable source of information than I could provide just on my own.

  6. 1..

    5-10 cm seems a little low for Winnipeg given current guidance, but I can't say it won't happen. They may be adjusting those amounts upwards on the next forecast update based on current trends.

  7. Snowfall projections for Winnipeg from model runs tonight..

    NAM..... 20 cm
    GEM .... 20 cm
    GFS .... 16 cm

    These are assuming 10:1 ratio.. amounts could be a bit higher based on higher SLRs.

    Don't have the Euro yet, but they're running around 7-10 cm from earlier run.

    Keep in mind though, it's the winds that will make things bad, regardless of the snow amounts. Winds look 40-50 sustained with gusts to 70 km/h by Friday night. With temps in the minus teens, that will make for lots of blowing and drifting snow.

  8. Winter storm Watches in effect for much of Southern Manitoba including Winnipeg.

    up to 20CM is expected coupled with very strong winds will make this for a real ugly day tomorrow. Tough travel day that's for sure.

  9. Thanks Rob for the information that you provide. I have followed your site for a number of years now and every day I check in to see what is "Really" happening with the weather.

    A number of my family members and friends use your site as the weather "Bible"!
    Looks like our "late" family Christmas will be cancelled!


  10. Guidance still on track for winter storm to affect southern MB Friday through Friday night into Saturday morning. As noted, winter storm watches have been issued for much of the RRV and SE MB, with the "B" word mentioned (blizzard) Distinct possibility that blizzard warnings may be required for parts of the RRV tomorrow. Stay tuned..

  11. Wow.. up to +8C in Grand Forks right now! Meanwhile it's -13C in the Pas.. gives you a good idea of the tight and pronounced thermal gradient across southern MB that will help energize tomorrow's storm.

  12. Hi Rob,

    Do you think that we may get more than 20CM with this storm?

  13. It's possible we may get more than 20 cm.. but right now, most guidance suggests amounts below 20 cm for Winnipeg, more in the 15 cm range for us. Some guidance hinting that the heaviest snowfall may occur over western RRV into the eastern slopes of the Riding Mtns. But overall, most guidance suggests a good swath of 10-20 cm over Winnipeg and the RRV, with the heaviest amounts falling Friday night.

    Snowfall amounts however will be difficult to measure accurately due to the strong winds, especially Friday night into early Saturday, which will result in considerable blowing and drifting snow. You will have much deeper drifts, but other areas may be swept clean. Overall though, it's looking like about 10-20 cm of fresh snow at this point.

  14. 6C in Sprague right now!

  15. EC likely issuing blizzard warning for Winnipeg and RRV on afternoon forecast update. Snow increasing Friday with blizzard conditions expected in Winnipeg area by Friday evening continuing into Saturday morning coincident with heaviest snow and strongest winds.

  16. 3 Pm Blizzard warning on EC website.

  17. Hopefully the worst being tomorrow night is true.. Anything to make that afternoon rush hour less than 3 hours.

  18. Quick question, is the heavy snowfall rates still likely even though environment Canada has no mentioning of it in there forecast? Or is it a part of the blizzard conditions? Let me know thank's!

  19. Mike..

    Yes, heaviest snow is expected Friday night over Winnipeg/RRV, and would be part of the blizzard wording used.

    It looks like light snow will develop overnight as the cold front pushes through and cold air starts to flood in. We could see a cm or two by Friday morning. Light snow will continue Friday becoming steadier and heavier as the main Colorado low moves up towards evening. Perhaps another 5 cm or so by evening. Then the real fun begins Friday evening through Friday night into early Saturday when snow rates increase and winds pick up.. with ensuing blizzard conditions likely. Could pick up another 10-15 cm Friday night, but drifts will make it seem like more. Note that blizzard conditions will likely start sooner north and west of Winnipeg where stronger winds will be coming earlier.

    Northerly winds will be peaking in Winnipeg overnight Friday into Saturday morning with gusts of 70 km/h or more possible. Conditions will gradually improve Saturday afternoon as storm pulls east.