Saturday, March 02, 2013

Winter storm system to impact southern MB Monday. Heaviest snow expected mainly south and west of Winnipeg

NAM prog valid 9 am Mon Mar 4
Low over North Dakota is
forecast to spread snow over
much of  southern MB and RRV
A storm system developing over southern Alberta is forecast to track into North Dakota Sunday bringing a swath of significant snowfall across much of southern Saskatchewan, North Dakota and portions of southern Manitoba.. especially to the south and west of Winnipeg.  A general 10-30 cm is forecast from southern Saskatchewan into North Dakota Sunday afternoon into Monday night, where winter storm warnings are now in effect. It looks like this system will also be bringing snow to southern MB, with the highest amounts expected over southwest MB and the southern RRV (including Emerson). Things become a little less clear as to how far north and east the snow from this system will spread, with varying opinions about how much snow will fall in Winnipeg. Some models are suggesting snow will get into the city with 10-15 cm or more possible Monday. Other models are saying the system will graze us, with minimal snowfall forecast. At this point, it looks like Winnipeg will be seeing some snow overnight Sunday through Monday with 5-10 cm possible, with greater amounts likely south of the city. However, this is still a developing system, and a slightly more northerly track will push heavier amounts of snow into Winnipeg, while a more southerly track will keep the snow mainly out of the city. Stay tuned on this storm system, and we'll keep you posted right here on any trends or changes as the system draws nearer. One thing's for sure.. if you have travel plans west or south of Winnipeg into North Dakota or western MB/eastern Saskatchewan late Sunday or Monday, be prepared for poor travelling conditions with snowcovered roads and poor visibility at times.

UPDATE: (11 am Sunday):  Snowfall warnings have been issued for SW Manitoba and southern RRV from Virden/Brandon areas to Morden/Emerson region. 10-25 cm forecast tonight through Monday. Warning area may be expanded northeast towards Winnipeg based on latest storm track and model guidance. Stay tuned for updated forecasts and warnings.   

Update: (330 pm Sunday) Snowfall warnings have been expanded to include areas from the Riding Mountains through St Rose, Gladstone, Portage, Carman, into Steinbach. 15-25 cm of snow possible tonight through Monday into early Tuesday.  Winnipeg currently NOT in the snowfall warning, but we will be getting snow, and it's possible the warnings may be extended further into the city.  Stay tuned for updated forecasts and warnings. (Winnipeg added to snowfall warning on 4:30 am Monday update)

NAM vs GEM re: snowfall projections over next 48 hours
(based on Saturday night model runs)


48 hr snowfall - NAM
valid 00z Sun - 00z Tue
green line is 7.5 cm
yellow line is 20 cm
48 hr snowfall - GEM
valid 00z Sun - 00z Tue

green line is 7.5 cm
yellow line is 20 cm

28 comments:

  1. Snow poll up! Let us know how much snow, if any, Winnipeg will get Monday..

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  2. Didn't someone (Anonymous) point out on a previous blog post on feb 21st that ec was forecasting 10-20 cm of snow for march 4-5 and that was beyond the model times? Wonder how they saw that...

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  3. I saw that message from Anon as well but at that time the only place saying that was Accuweather

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  4. I'm curious about that too. That's the best 12 day forecast I've ever seen (or luckiest!)

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  5. I know weather network was showing accumulating snow for march 4 back on Feb 21. However, on their next model run it showed sunny skies.

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  6. Well, I see our "sunny" Monday is now calling for 5-10 cm of snow, as the GEM finally joins the party. Funny how a few days ago, the GEM was the only model advertising snow for us, while everyone else was saying a miss. Then they all flipped. Goes to show that even an outlier can be right sometimes.

    I'm surprised there aren't any snowfall warnings out for SW MB and southern RRV, especially with warnings out in northern ND and SE SK. Looks like those areas could see a good 15-25 cm. I see ND is forecasting up to 30 cm near the US border.

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  7. Here's hoping that March coming in like a lion and finishing like a lamb holds true. Don't need any more snowstorms after this one!

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  8. Snowfall projections for Winnipeg from the 5 main models + NAEFS ensemble based on 00Z or 06Z runs. Assuming 10:1 snow ratios.

    NAM ......... 14 cm
    RGEM ........ 10 cm
    ECMWF ....... 9 cm
    GFS ......... 7 cm
    GGEM ........ 6 cm
    NAEFS ...... 8 cm (50% median)

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  9. It's funny that Accuweather was calling for that way back then but then for most of the week they were calling for nothing untill late last night and today calling for around 3cm

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  10. Hey Rob how will this thing play out if it actully does hit us. Will most of the snow come during the day and end in the early evening monday?

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  11. Daryl.. Looks like snow will be spreading into Winnipeg by midnight or so and then increasing overnight into early Monday (just what you need for a Monday morning commute..) Snow will continue steadily through Monday into Monday evening before tapering off early Tuesday morning. At least, that's the general consensus right now.

    12Z model runs coming in with higher snowfall amounts for Winnipeg... NAM now showing 20 cm by Tuesday morning, RGEM 17 cm. Again, that's using 10:1 snow ratios. Snowfall amounts could be 25% higher based on higher ratios (12-13:1 ratios forecast)

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  12. Rob, do you think E.C. will post warnings at the 11:00 AM forecast update or later today based the snowfall amounts expected over the next 24 hours.

    And, do you think we in Winnipeg have a good shot at, at least 10-15 CM with this based on the latest trends?

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  13. Anonymous.. EC just issued snowfall warnings for SW MB on the 11 am update. That may expand a bit north and east by the afternoon update. And yes, I think Winnipeg has a very good chance at 10-15 cm based on latest guidance.. in fact, 20 cm is possible if you believe the latest hi-res models.

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  14. Thanks for all the up to date info guys appreciate it alot any thoughts on how much snow Brandon should expect?

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  15. I was the one that seen it but it was forecast on my EC app for my phone...

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  16. Seems snowstorms like hitting us on Mondays lately.. That blizzard in February was on a Monday too.

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  17. Accuweather just did a 10am update and they still have us just along the edge of the system.

    Here is their sunday morning update newscast

    http://www.accuweather.com/en/weather-news/minneapolis-chicago-snow-may-r/7318939

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  18. Accuweather site under news/video has a short article reminding us why accurate weather forecasting is so challenging.

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  19. At least it won't be brutally cold on the backside. What are winds supposed to be like?

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  20. @anon (11:02 am) Brandon's looking at 15 cm or so.. Winds will be picking up front the east as well by tonight with gusts to 50 or 60 km/h possible, so some blowing and drifting snow likely as well.

    As for us, winds will be from the east at 30 km/h, with gusts to 40 or so at times tonight into Monday. Fairly brisk but not terribly strong, so blowing and drifting snow shouldn't be a major issue for us.

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  21. Rob,
    Do you think the snowfall warning will be expanded to include Portage and Winnipeg as well as southeast MB with the afternoon forecast update?

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  22. According to the latest PASPC discussion, it looks Portage, Steinbach, Minnedosa and St Rose regions will be added on the afternoon update. Winnipeg is a tough call, and ensemble guidance still indicates the bulk of the snow will fall south and west of Winnipeg.. but it's going to be close.. very close. Personally, I'd probably lean towards including Winnipeg as well based on how close we will be to warning criteria and latest model trends. Snowfall warning criteria is 10 cm within 12 hours or less.. and I think that's do-able for Winnipeg overnight into tomorrow evening.

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  23. Rob, in your opinion, does NAM still remain the outlier on this with it's 20CM prediction for Winnipeg?

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  24. How much snowfall does it typically take to ground flights out of Winnipeg? Do you think the airlines will still be operating tomorrow?

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  25. Rob do you think we could get 20cm or more of snow in Winnipeg? I have seen the NAM, GFS, and GEM-GLB all go for heavy snow in Winnipeg and the deformation zone up in the interlakes. Is it possible that EC is wrong on where the deformation will setup, all of the models are showing us even getting in the southern end of the low which would be fairly close to the warm sector. What do you think?

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  26. Mike.. It's quite possible that the deformation zone will set up northeast of Winnipeg, giving us more snow. The models have all been trending further north with each run, and looking at the latest NAM , it's showing more of an inverted trof setup across the RRV that tends to bring heavier snow into Winnipeg. So yes, the potential for 20 cm is there, but I don't have enough confidence to say it will happen.

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  27. Snowfall warnings just expanded to include Portage Steinbach and Minnedosa areas. Winnipeg not in the warning at this time which surprises me a little given the latest models guidance which have all been trending further north with each run putting Winnipeg into some heavier snowfall tomorrow.

    Rob, do you think it's a gamble from E.C. not to include Winnipeg in the warning or is it just simply that there's still too much uncertainty on snowfall amounts here for the time being?

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  28. Well.. it's a tough call for Winnipeg. Most of the ensemble guidance is still suggesting the heaviest snow will be falling just south and west of the city, but it will be close. NAM is the most aggressive by far.. now saying 25 cm on the 18z run while everyone else is in the 10-15 cm camp. Is it a gamble? Perhaps.. but EC is figuring Winnipeg will be shy of the snowfall warning criteria of 10 cm within 12 hours. I just get uneasy when I see slow moving inverted trofs with lots of moisture pushing across Winnipeg in March.. but, we'll see.

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