Saturday, 16 February 2013

Winter Storm to End the Long Weekend

     The tradition of stormy long weekends here in Manitoba continues. A strong Alberta Clipper is set to start moving into Manitoba tomorrow, and will continue to have an impact on our province on part of Monday. However, this system is particularly complex, which is making it difficult to determine exactly what will happen. Models differ widely in amounts, timing and precipitation types. It seems the only thing that models agree on right now is for very strong winds and blowing snow on Monday. In addition, almost all of Manitoba is expected to get some snow with this system due to how large the system may get. After looking at the models for a couple hours this morning, here's the best forecast I can provide right now: (I'll give updates throughout the weekend)

GFS model forecast for Sunday evening

     The southern Manitoba situation tomorrow morning and afternoon is complicated. What is certain is that we will be in the ''warm sector'' of the system for most of the day. Temperatures are expected to rise slightly above zero in southwestern Manitoba in the afternoon. Here in the RRV and southeastern Manitoba, highs between -2°C and 0°C are expected in general, and these highs will likely be reached late afternoon or early evening. Winds will be brisk out of the south or southeast. Light precipitation is expected on and off through the morning and afternoon throughout southern Manitoba, however timing and location of this is too uncertain to point out. It is important to note however that freezing rain and ice pellets are a possibility thanks to some above zero air above the surface. Although amounts are expected to remain light, it could certainly be enough to make travel quite slick in some areas. The best chance for this light freezing drizzle or rain will be in southwestern Manitoba and along the US Border. This threat will diminish later in the afternoon in southwestern Manitoba and here in eastern areas in the evening as colder air moves in. The heaviest precipitation tomorrow in the day will be along and north of the warm front, in other words generally in the Interlake, central, western and eastern Manitoba. Precipitation in those areas will remain as snow.

     The centre of the low pressure system is expected to move over southern Manitoba in the evening. Thus, light to even calm winds are expected in that timeframe (would be brief however). The cold front will quickly sweep across the area however, and at this point it is expected to reach Winnipeg by mid or late evening. Winds will strengthen dramatically behind this front, and snow will begin falling either as the front passes or a little before it passes (likely a couple hours before). Snow will continue through most of the night, and winds will continue to strengthen.

      This is where the most problematic part of the system begins. Winds are expected to be out of the northwest or north at about 40 to 50 km/h with gusts to 60 km/h in the RRV on Monday morning. This will create serious blowing snow in open areas, especially if we get a lot of new snow.

     At this point, it looks like snowfall will wind down in the morning, with just a few flurries in the  afternoon here and there. Total amounts are expected to be in the 5-10 cm range in Winnipeg, but higher amounts are definitely possible. Heaviest snow totals with this system right now are expected in central and eastern Manitoba and then into northwestern Ontario.

Temperatures will remain steady or fall slightly throughout the day on Monday. We will likely be waking up to temperatures around -10°C in Winnipeg on Monday morning, and then temperatures will likely remain steady in the mid minus teens through the day. Lows in the minus twenties are expected Tuesday morning.

     This is how I see this system right now. With the great uncertainty in the models, I wouldn't be surprised if things end up a little different. That's why I'll be updating later today, and of course through the day on Sunday.


  1. Overall, not much has changed with my forecast so far.
    All I can say is that it is increasingly looking like snowfall amounts for Winnipeg, and southern Manitoba in general, will remain on the lower side (5-10 cm). Heaviest amounts still look to be in central and eastern Manitoba as I highlighted in this post this morning. Timing has not changed much from what I have said in this post as well. I will continue to keep you all up to date.

  2. There are a few changes to be made to my forecast now. It looks likely that there will be a narrow band of heavy snow somewhere just around the north side of the low pressure centre. Most models are putting this band south of the Trans-Canada, and it could ride along the International Border. This band will give much higher amounts than surrounding areas. 10-20 cm is certainly not out of the question under this heavier band, and right now models are putting these highest amounts in the extreme southeast corner of the province (Sprague area and in northwestern Ontario where 15-25 cm is likely). Right now, it looks like it's this band that will cause the heaviest snow totals for this system. Unfortunately, Winnipeg could be right on the edge of the band, which makes it difficult to make a forecast for the city. I'm still keeping with my forecast of 5-10 cm right now.
    Another thing, is that there could be more snowfall this afternoon, before the main snowfall tonight, than I had thought yesterday. Some models give us a few cm at that time, but the thing is that it will be more hit and miss than widespread. I'll update on in the afternoon.

    Winds still look quite strong tomorrow, especially in the morning. Sustained winds of 50 km/h and gusts to 70 km/h are possible in the Red River Valley. Blizzard conditions will exist as a result, mainly in rural areas outside of Winnipeg. For the city, blowing snow would be the main threat. I wouldn't be surprised to see some highways shut down. Winds will diminish slightly in the afternoon, likely to 40 gusting to 60 km/h before dimininishing even more in the evening. We wont see a full reprieve from the breezy conditions until Tuesday afternoon or so.

  3. Band of freezing rain, ice pellets and snow grains moving through the Red River Valley right now. Getting some ice pellets here in Winnipeg as I write this. This band will continue to move eastward and be out of the area by afternoon. It appears this band may be along or near the warm front.

  4. Some moderate freezing rain fell south of Winnipeg with the band. It fell long enough for a decent amount of ice to accumulate on surface. Here's a photo from Steinbach of ice on a car:

    The main band is pushing east, so if you are in the Gimli, Whiteshell, Lac du Bonnet and Victoria Beach regions, watch out for very slick road conditions soon. Behind the band we're not completely out of the clear however. Light freezing drizzle, ice pellets or snow grains are still coming down, it's just lighter than with the main band.

  5. My St. Vital Data page has now been improved. In the coming days and weeks, I'll be adding my data that goes back to 2007. (However this does not include temperature. I have only been keeping track of temperatures at my station since April 2011)

  6. Temperatures are starting to pop above zero along the US Border. Morden is at 2°C and Melita at +0°C.

  7. A variety of warnings have been issued by Environment Canada for tonight and tomorrow. Here they are:

    Blizzard warnings for the Steinbach, Dominion City, Morden, Winkler, Emerson, Morris and Gretna areas (southern RRV)

    Blowing snow warnings for the city of Winnipeg and Carman, Portage, Selkirk, Eriksdale Gimli, Dugald and Grand Beach areas (northern RRV)

    Snowfall warnings for the Sprague and Whiteshell areas.

    Right now, it looks like the heaviest band of snowfall (the one I mentioned this morning) will remain south of the Trans-Canada, but it will be a close call for Winnipeg. Around 10 cm is forecast along the US Border (Morden, Emerson and Steinbach areas included) and around 15 cm for the Sprague region. 5-10 cm still looking like a good bet for Winnipeg, however I'm thinking it'll probably be on the low side of that scale (northern RRV in general). 15-20 cm is expected in parts of northwestern Ontario (Kenora and Fort Frances regions).

  8. Winds have calmed in the city now as the low pressure centre passes nearby. The cold front should pass through very soon with increasing north/northwest winds and falling temperatures early evening. Snow should begin in a couple hours or so; I will update this when it is more certain.

  9. Front has passed Winnipeg, winds have switched to a more northwesterly direction. Temperatures will begin to drop from now on and winds will slowly ramp up. Snow should begin in a couple hours still.

  10. Wow what a blustery scene out there! The winds howled through the night with snow and severe blowing snow. Got a drift in my yard of 80 cm deep now, that's the deepest drift I've measured since I started measuring snow in 2009.

    Highway 1 is closed from Winnipeg to Portage as well as Highway 75 from Wpg to Morris.