Sunday, March 23, 2014

Frigid first weekend of "spring".. late season -30C weather over southern Manitoba as cold Marches on

The official first weekend of spring was anything but springlike over southern Manitoba as a frigid Arctic airmass brought abnormally cold temperatures to the area, averaging some 15-20C below normal for late March.  After a brisk Saturday when temperatures struggled to an afternoon high of -13C in Winnipeg (along with -25 windchills), clear skies and light winds allowed temperatures to bottom out to a frigid -28.4C at Winnipeg airport early Sunday morning. Although well below normal (average highs are now +2c, lows -8C), it was not a record low for the day (-32.2C on March 23 1974)  Temperatures this morning were even colder outside the city, with several sites recording lows below -30C, abnormally late for such temperatures even for southern MB.

Cold spots across southern Manitoba (March 23 2014)

Great Falls ........  -33.6C  (Pine Falls)
Gimli ..................  -33.4C
Fisher Branch ....  -32.2C
Wasagaming .....  -32.3C
Indian Bay...........  -32.0C (Falcon Lake) 
Pinawa ..............   -31.5C     
Victoria Beach ...   -31.0C

The cold conditions are just an extension of what southern Manitoba has been experiencing for the last 4 months now with consistently below normal temperatures. Over the past 9 weeks for example, only 9 days have been above normal in Winnipeg. The cold conditions will gradually ease over the next few days but temperatures will remain below normal much of the week before a moderating trend gets temperatures closer to normal by the weekend. So far, March is averaging around -13C in Winnipeg, well below the average March temperature of -5.8C (1981-2010 normal)  The below normal temperatures this week will ensure that March finishes as the city's 6th consecutive month below normal. 

22 comments:

  1. Rob, have you seen what some of the models are hinting at next weekend??? That is some very warm air to our south. It is also showing the potential for some active weather!! You know, areas in the Black Hills South Dakota will probably be getting into the mid 20's C with that airmass!!

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  2. By the way, that 1974 record low of -32C on this date for Winnipeg had a high of only -23.3C that day, the latest date on record with a high of -20C or lower here. March 1974 was about 5C colder than average and they had a similar snow depth at the airport at this time (30 cm) as we do now. The snow that year was pretty much gone by April 16th when they started getting into double digit temperatures. So there's some hope that this cold pattern we're in can turn around by mid April.

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  3. A few flurries possible tomorrow as a weak cold front passes through (yes, believe it or not, another cold front) but nothing major. Next system of interest will be a clipper crossing North Dakota Wednesday. Current models show a fairly narrow but potentially heavy west-east band of snow across northern ND and along the international border.. perhaps 10-15 cm in this swath. Will have to keep an eye on this to see if storm track or intensity changes for possible impacts on southern MB.

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  4. Those forecasted temperatures of 4C this upcoming weekend, are looking really nice right now!!

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  5. Yeah, it will of course only be nice if temps really do indeed reach plus 4 or plus 5 this weekend which I would say is probably somewhat doubtful.

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  6. Rob, I'm hearing from some that there are hints of some of a large warmup come the 2nd week of April. Not sure about that, but what are your thoughts on this?

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  7. Yes, those highs of +4C for the weekend look optimisitic, at least for Winnipeg. Saturday looking like the milder of the two days, as we get a south-southeast flow ahead of a clipper system. But +4C seems overdone.. we usually need a westerly flow of Pacific air to get us that mild. Maybe 0 or +1C more likely unless that clipper system tracks further north and we we can get a southwest flow in the warm sector. We may get a shot of snow with that clipper Saturday night before things cool off again behind it Sunday with northerly winds. So that +4C for Sunday is not looking too likely at this point and I suspect that forecast will be trending down in the days ahead.

    (NOTE: Day 6-7 forecasts are automated output from the Canadian ensemble system (CEFS) which can be a bit coarse on trends and system timing. That differs from the Day 3-5 forecasts which are based on the deterministic GLB model, which has higher resolution. That is why you sometimes see a big difference between the Day 5 and the day 6 forecasts.. they're produced differently.)

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  8. Maritimes will be interesting to watch on Wednesday with explosive east coast bomb tracking just offshore Nova Scotia. Models deepening low some 30 mb in 12 hours Tuesday night (twice the rate of a "bomb") down to an amazing 955-960 mb by Wednesday morning, similar to the 959 mb "white Juan" storm back in 2004. Blizzard conditions likely across much of western and central NS, PEI, and SE NB Wednesday where 30-50 cm is possible along with embedded thundersnow giving extreme snowfall rates of 5-10 cm/hr at times. Powerful winds gusting to 100-120 km/h will produce storm surges along NS coast, and sea ice surges along Northumberland strait along with possible power outages. A wild Wednesday coming up in the Maritimes..

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  9. Rick Mercer report on this winter. Funny!
    http://youtu.be/wkDvqQKGgDA

    Chris in Westwood

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  10. >> Anonymous said...Rob, I'm hearing from some that there are hints of some of a large warmup come the 2nd week of April. Not sure about that, but what are your thoughts on this?

    I'm cautiously optimistic that things will be turning around by mid April. There are signs that the Arctic vortex will be easing by mid April which will allow more persistent warmth to finally become established here as we get a more zonal flow of Pacific air. That will allow the snowpack to erode more quickly, which then makes it easier for things to warm up. We don't even have to get to an above normal pattern.. normal highs by mid April are +10C, so if we can even get back to a "normal" pattern for a prolonged period, that would be a major improvement over what we've been seeing over the past 4 months. I am so tired of this 1 day normal, 6 days below nonsense.

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  11. Hi Rob,

    I see you briefly mentioned about a clipper on Sunday but now the WN is calling for 5-10 cm of snow on Sat/Sun.

    Is this going to be a significant snowfall. Nothing would surprise me as it is spring now and the end of March.

    Thanks

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  12. Rob, to continue from your post yesterday, I am noticing more consistent long range runs from Accuweather showing a big warm-up around the 2nd week of April. I also read yesterday from WeatherCentre stating that the polar vortex is collapsing & that the final warming of the winter is occuring with the likelyhood of sustained warmer weather within 2 weeks. Waht are your thoughts? Will we finally see a change coming?

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  13. Anonymous... I really can't add much more to what I posted above. All I can say is that it's a positive sign that there are more consistent signals of a pattern change coming within a couple of weeks. It's got to change at some point. The main thing is we need to get rid of this snowpack, gradual enough that we don't have flooding problems but quick enough that we can enjoy some nice mild spring weather soon. I just hope any pattern change is a prolonged change, not just a temporary interruption to this exhaustingly persistent below normal pattern we've been stuck in since December.

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  14. >> Hi Rob,I see you briefly mentioned about a clipper on Sunday but now the WN is calling for 5-10 cm of snow on Sat/Sun. Is this going to be a significant snowfall. Nothing would surprise me as it is spring now and the end of March.



    Right now general model consensus is for a minor snow fall of 2-4 cm for Winnipeg with Saturday's system, although I've been burned by these minor events before and we ended up getting 5 to 10 cm so I can't rule it out. Note that we can get significant snow falls into May so a snowfall in late March is not unusual.

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  15. Rob, can you please explain why you are consistently around 3C warmer than the airport on days where we have light winds and full solar??

    I thought that the deeper snowpack in your yard would radiate more of the sun's energy away??

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  16. For Saturday's possible snowfall, It could be my last before I go to a 3-week vacation in the Philippines with my family, where I will have to endure the temperatures of 35C which may feel like 40 with humidity. I hope all the snow is gone and no more late season snowfalls in April or May upon my return from the Philippines before the end of April.

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  17. >> Anonymous said...Rob, can you please explain why you are consistently around 3C warmer than the airport on days where we have light winds and full solar??

    That's a common effect with backyard weather stations, especially in the spring as the sun gets stronger. In sunny light wind situations, the air gets warmed up in sheltered areas (such as backyards), even with a deep snowpack.. so that readings from residential stations are often warmer than the more exposed airport site.

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  18. >> Anonymous said...For Saturday's possible snowfall, It could be my last before I go to a 3-week vacation in the Philippines with my family, where I will have to endure the temperatures of 35C which may feel like 40 with humidity. I hope all the snow is gone and no more late season snowfalls in April or May upon my return from the Philippines before the end of April.

    Lucky you! Have a great trip!

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  19. Is Saturday still on track for 2-4 or has it backed off?

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  20. Is Saturday still on track for 2-4 or has it backed off?

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  21. Looks like we may see a cm or two out of it Saturday afternoon/night.. but temperatures should be mild enough for it to melt initially as well, so I'm not expecting much accumulation overall.

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  22. Thanks Rob
    We snow plow and are on contract till end of the month.
    Hoping to head to southern ontario for a break to see family and want to cheat a little and leave early, but sat chance of snow is keeping us here.

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