Tuesday, December 03, 2013

Driving conditions to worsen Wednesday into Thursday as storm system brings snow and increasing winds to southern MB..

Model ensemble snowfall totals
forecast through Thu morning (cm)
15-20 cm possible over RRV
and SE MB
The storm system that will be tracking across the Dakotas through Minnesota will be spreading snow across southern MB overnight through Wednesday, along with increasing northerly winds as the system intensifies to our southeast. Although the heaviest amounts of snow are expected mainly across northern Minnesota into NW Ontario with this system, it looks like southeastern MB and the Red River valley will still be getting a good amount of snow on the northwestern flank of the storm. Light snow this evening will pick up overnight with about 2-4 cm expected by the Wednesday morning commute. Snow will continue all day Wednesday into Wednesday night becoming moderate at times. Another 10 cm of snow is expected in the Winnipeg area by Thursday morning with up to 15 cm over areas to our south and east.  Snow will finally taper Thursday but not before storm totals of 10-20 cm over the RRV and SE Manitoba. In addition to the snow, northerly winds will be steadily increasing Wednesday as the storm intensifies, with gusts to 50 or 60 km/h likely by afternoon and evening.  This will lead to extensive blowing and drifting snow with poor visibilities becoming more frequent by evening especially in open areas. As a result, driving conditions will steadily worsen Wednesday into Wednesday night, so allow a lot of time if you plan on travelling. The snowfall will be winding up Thursday, but gusty winds and cold temperatures will continue to produce poor driving conditions especially Thursday morning. Allow plenty of time for commuting and getting to your destination over the next couple of days as this next bout of wintery weather hits southern MB.  

Environment Canada has issued a special weather statement for southern MB concerning this storm system, with winter storm warnings in effect across North Dakota and northern Minnesota.

36 comments:

  1. Rob, do you think any Watches or Warning will be issued for this storm?

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  2. Can someone please tell me the criteria that needs to be, in order for a blowing snow warning??

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  3. >> Anonymous said... Rob, do you think any Watches or Warning will be issued for this storm?

    It's possible.. especially for the southern RRV and SE MB where snowfall totals will be highest. In addition, southern RRV will see the strongest northerly winds which will make them more prone to blowing snow and poor visibility. You need at least 10 cm of snow within 12 hours for a snowfall warning, or 25 cm of snow within 24 hours for a winter storm warning. Both these may come close in some areas. In addition, winter storm warnings can be issued for at least 10 cm of snow along with extensive blowing snow for at least 3 hours, which is quite possible in the RRV.

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  4. How much snow in Winnipeg? ~10cm?

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  5. >> Anonymous said... Can someone please tell me the criteria that needs to be, in order for a blowing snow warning??

    You need at least 3 hours with blowing snow reducing visibility to 1/2 mile or less. Generally these types of warnings are reserved for cases where there is no snow falling, but winds are producing considerable blowing snow and poor visibilities over a widespread area.

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  6. Light snow continues through the RRV this evening with radar showing it intensifying south of Winnipeg. This isn't even associated with the main storm system yet!

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  7. Hey Rob, do you think it's possible that we will see even more snow than what's anticipated given the very fluffy nature of snow due to the colder temperatures?

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  8. Any chance for near to blizzard like conditions in the RRV with this storm?

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  9. The rate the snow is coming down right now in Winnipeg, we will easily pick up our 2-4 cm tonight.

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  10. Yeah, I've already picked up 2-3 cm as of 730 pm and the snow is still falling.. very light fluffy stuff that accumulates easily. This wasn't even part of the main system which was supposed to start overnight! This band is just sitting over us and not moving. I was kind of leery about this inverted trof kind of set up, and it looks like it may be another one of those cases here where it brings you a lot more snow than expected :/

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  11. Rob, do you think we will pickup 5+ CM tonight now?

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  12. Not even a few hours in to the first evening, and I already lost the snow poll. Oh my....lol.

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  13. 4 cm of very light fluffy snow at my place in this evening's surprise snowburst. Snow has pretty much ended here as we wait for the main synoptic snow to start overnight into Wednesday morning.

    This evening's snowburst shows how difficult it is to accurately predict snowfall amounts. This was pretty much a mesoscale band, possibly convective, that set up over Winnipeg and the RRV with very high snow:water ratios (high "fluff" factor) and optimum snow growth temperatures to maximize snow crystal growth. Very hard to predict this event ahead of time, not only for the models, but even just looking at real time radar. Keep in mind that general snowfall totals can be locally enhanced depending on if and where these smaller scale snowbands set up. Watch the radar for these narrow bands of heavier snow embdedded in the overall synoptic snow shield over the next day or so.

    We now wait for the main event to start...

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  14. snowfall warning issued! looks like a fairly major storm / event for wpg after all.

    City of Winnipeg
    2:30 AM CST Wednesday 04 December 2013
    Snowfall warning for
    City of Winnipeg issued

    15 to 25 cm of snow and blowing snow today and tonight.

    A weather system currently located south of Minnesota has spread snow across Southern Manitoba. This system is forecast to intensify as it tracks over the Great Lakes during the next couple of days. South-Central and Southeastern Manitoba will be on the western edge of this system and receive the worst conditions.

    This weather system will bring near 10 cm of snow today over the above regions followed by 5 to 10 cm of snow tonight into Thursday morning. This storm will persist for at least 24 hours and total snowfall amounts expected to reach the 15 to 25 cm range. Gradually strengthening north winds today and tonight will result in blowing snow and reduced visibilities.

    Conditions will gradually improve later on Thursday as the system moves away but with either steady or dropping temperatures.

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  15. Winds have already turned NW and picked up in portage la prairie . Visibility already down too 1 KM.

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  16. Can't remember the last time we had a snowfall warning! Even with last years snowy winter did we even get one snowfall warning?

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  17. I can see looking back that we did have a snowfall warning in that pre remembrance day storm last year.

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  18. Hi Rob, are you able to tell me, if we are in a LA NINA year right now ??( even a weak one )or is it completely neutral ?? I've read some articles that say that very warm air aloft and warm ocean content in sections of the pacific is causing all this cold air to crash down on us. I know this is not your expertise, but any insight would be greatly appreciated. Thanks.

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  19. Rob said "You need at least 10 cm of snow within 12 hours for a snowfall warning..."

    JS just said on the radio that it's 10 cm within 24 hours. Huh.

    This EC page says Rob is correct.
    http://www.ec.gc.ca/meteo-weather/default.asp?n=D9553AB5-1#snowfall

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  20. 2 to 3cm since 8am this morning in St James

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  21. It seems our best or is that the worst winter storms are in doubt until a few hours before the event. Are there Models which have a better record.

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  22. Tough to measure new snowfall today due to blowing/drifting, but I'm estimating another 7 cm today for a storm total of 13 cm so far and snow continues. Probably looking at another 5 cm or so tonight, although again, it will be tough to accurately measure as blowing/drifting will produce deeper drifts and make it seem like more snow than that.

    Note that the snow today was a much finer, smaller crystal compared to the larger fluffy stuff last evening. Definitely a different crystal composition with the system snow today.

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  23. >> Anonymous said... Hi Rob, are you able to tell me, if we are in a LA NINA year right now ??( even a weak one )or is it completely neutral ??

    According to NOAA, we're in a neutral phase right now, and this is expected to continue into the spring. Latest update available at..

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

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  24. Rob, is it good bet to say that this December will be one coldest in a long time?

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  25. With all this fresh deep snowpack now , it will really help in keeping our temperatures in the cellar for awhile now. If there is one record low that we could possibly have a go at, would be Saturday morning!!

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  26. 8-9 cm in 12 hours I got in St-James

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  27. Another 2 cm last night.. storm total 15 cm at my place, but seemed like a lot more due to drifting and blowing snow. Snow is quite thick too.. side streets are tough to move through but main routes are plowed nicely.

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  28. So we'll go with 10-15 cm as the winning pick on the snow poll (total snowfall Tue-Wed) with 15-25 cm as honourable mention. Good job to the 15 respondents who picked 10-15 cm! (For the record, I picked 5-10 cm) That was a tough forecast!

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  29. Thanks for the continued updates through out the storm. I see a high of -12 today for Winnipeg. I think that might be wishful thinking as I've seen the temperature just keep falling this morning.

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  30. OK so now that we can all breath a sigh of relief here in the city for not getting a 20+cm dump of snow, let's move on to how long this deep freeze will last? 7 days 30 days? I could not believe that Toronto held +15°C for three hours today.

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  31. -45 C windchill in regina this evening. I hope that does not head into Winnipeg the next few days :(

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  32. Rob, even though the official forecast does not call for any -30 overnight lows in Winnipeg the next while , would you say there is a fair chance of getting our first -30 in this cold snap ?

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  33. >> Anonymous said... Rob, even though the official forecast does not call for any -30 overnight lows in Winnipeg the next while , would you say there is a fair chance of getting our first -30 in this cold snap ?

    Absolutely. Forecast low for early Sunday is -29C, but it can easily be a few degrees colder. With daytime highs at or below the -20C mark into next week, it won't be too difficult to hit -30C a couple of nights, particularly at Winnipeg airport with a NW drainage wind.

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  34. Interesting situation for Sunday morning.. Arctic ridge giving the extreme cold over AB and SW SK actually builds to our south by Sunday morning to lie over Montana, ND and Minnesota. That puts Winnipeg and the RRV in a bit of a southerly flow out of the ridge Saturday night into Sunday morning which may save the airport from hitting -30C early Sunday with a bit of a south wind coming in off the city. -30C temps more likely over southern suburbs and the RRV outside the Perimeter in that setup with the coldest readings near and south of the intl border in the ridge itself.

    But really, we're only talking a few degrees here.. it'll be cold no matter where you are! Stay warm!

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  35. Rob ,
    Thanks for continuing to provide not only a great Website, twitter comments and Blog and Links, but also an inspiration for others who are  creating their own sites locally. Thanks to your efforts, I like to think we have the best weather and climate coverage in spite of the shenanigans at EC .

    Could some of the Climate Links on the Blog page be out of date .  An example. The Blogs El Nino index produces a link on my laptop which has not been updated since Sept 22 2012 at 
    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/images3/nino34SSTMon.gif
    Maybe Parts of NOAA may have quit duplicating work produced elsewhere in NWS etc etc.  Sounds familiar eh?

    What I use below is very similar but I checked the Blogs climate links and they also provide great coverage.and Links. I use
    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
    provided I suspect by this blog at some time in the past

    My reason for checking this was  JJ Cs Winnipeg Weather blog produced some interesting charts which referred to record November Hi Pressure (and the lowest Nov Temp since 1996)readings and listed the other record years at..http://jjwinnipegweather.blogspot.ca/2013/12/pleasant-start-to-november-but-cold-and.html <
    Impressive list to say the Least . Put a spring in my step if you catch my  drift. Such warm dry and short winters those were.
    1964-5,1978-9,1996-7, and 2008-9, and the question is 2013-14?? We appear to be off to a great start! Worth watching at least.

    I Apologize if this incorrectly acknowledges other websites and data. and Length
    Don

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  36. Thanks for the comments Don. It's quite possible that some of my links are out of date as there are quite a few and I don't check them all on a regular basis. So I appreciate any input from people who find broken links so I can update them.

    I'll replace that outdated El Nino link with this one..

    http://www.cpc.ncep.noaa.gov/products/predictions/90day/tools/briefing/sstsa.gif

    And thanks for the link to jj's weather blog.. some good stuff there! I don't get to update my blog as much as I'd like, so it's good to see others sharing their info as well!

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