Sunday, March 31, 2013

Cold March ends on... what else.. a cold note..

30 day temperature graph
for Winnipeg showing
abnormally cold weather
through March 2013
After a couple of days which seemed to hint that perhaps spring was finally on the way, colder air has once again returned over southern MB with brisk northwest winds and below normal temperatures today. It's a fitting end to what has been a long and frustratingly cold March which saw little in the way of thawing temperatures to help erase a 40-60 cm snowpack in Winnipeg and throughout the Red River valley. Snow cover was still 40 cm deep in Winnipeg as of March 31st, the deepest snow cover this late since 1996.  There were only 2 days this month where the temperature rose above freezing at Winnipeg airport, March 28th and 30th, with a maximum of only +2.3C on the 28th. (Consider that March 2012 had an average monthly temperature of +2.2C!) Normally, Winnipeg sees at least 15 days above freezing in March with at least 1-2 days reaching 10C or more. Temperatures this month have been below normal every day since March 10th, with the coldest weather of the month between the 13th and 21st.. about the same time a record March heat wave was occurring just a year earlier. March 2013 will finish with an average temperature of about -11C, some 5C below normal for March and the coldest March in the city since 2002 (-11.7C) It also was a remarkable 13C colder than March 2012.

March 2013 mean
temperature anomalies
shows extent of cold
weather this month
The outlook this week calls for a continuation of below normal temperatures, with a brief moderation around Wednesday. Not much in the way of precipitation is expected this week, although there are hints of a possible storm system tracking through the Dakotas by next Saturday that may bring some precipitation over southern MB. Longer range outlook calls for a hopeful sign of a pattern change to warmer weather by mid April as the stubborn Arctic block relaxes. Let's hope! 

37 comments:

  1. Interestingly, the last truly normal March was in 2008. 2009, 2011 and 2013 were well-below, and 2010 and 2012 were well-above.

    Rob, taking standard deviations into account, do you think it's accurate to say the last normal March in terms of temps. were in 2008?

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  2. 21.8C in Aschroft, BC yesterday.

    That is the warmest temperature in Canada this year.

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  3. 1 - 2 cm of snow this afternoon in the Southdale area of southeast Winnipeg from that narrow band over the eastern side of the city.

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  4. Andrew..

    For Winnipeg airport, March 2009 had a mean temperature of -7.8C, while March 2008 was -8.5C (same as 2011). The 1971-2000 March "normal" is -6.1C, so both were below normal. March 2007 had an average of -5.1C, which was just slightly above normal while March 2006 was -6.1C, bang on normal. Note that March has a SD of 3.5C, which accounts for large variability year to year.

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  5. Plenty of 20C temps in the Okanagan today under sunny blue skies. For early spring weather, you just can't beat southern interior BC. Normal highs are in the 12-14C range now.. a full month ahead of southern MB.

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  6. 25.0C in Hope, BC new highest this year in Canada.

    Agassiz with the first humidex (26) as well.

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  7. Coldest April morning since 1997 today... Gosh still feels and looks like February out there.

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  8. Today's Euro model has come in with a more northern track on Saturday's system tracking through the Dakotas.. bringing 15 mm of mixed precip over Winnipeg Friday night into Saturday. GFS is well south with precip confined south of the US border, while the GGEM clips SW MB with snow. Too early to say who's right.. but always a concern when the Euro starts trending wetter. Will keep an eye on it..

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  9. John Sauder is forecasting 8 to 10C for mid next week.

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  10. Rob, that 15 mm by the ECMWF, is it 15 mm in the form of snow (majority of it)? At this rate, we'll still have piles of snow left over from winter by the May long weekend.

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  11. That 15 mm from the Euro starts as some rain, before changing to snow Friday night into Saturday.. perhaps 5 cm worth. I see the latest 18Z GFS has trended north as well now, with 5-10 cm of snow noted for Winnipeg Friday afternoon into Saturday morning.

    We'll have to see if later runs continue this trend, including the GGEM. Stay tuned..

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  12. Euro calling for rain Friday....i'd say that's very optimistic and unlikely. Not warm enough for rain around here. We are still in full winter mode and will be much of the week.

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  13. Accuweather is back to calling for a large snowfall for Friday night. Not 20-25cm like they were originally calling for but 10-15cm.

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  14. Euro and GFS have backed off on amounts for Winnipeg for Friday-Saturday system, now calling for 2-3 cm of snow instead of the 5-10 cm from earlier runs. GGEM still misses us completely, but clips SW MB. Best bet is for main swath of snow to track across southern SK and SW MB into North Dakota Friday into Saturday. Winnipeg may get some snow Friday night, but bulk of snow should be mainly to our south and west. Will continue to monitor to see if there's any trend to push snow further north and east into Winnipeg..

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  15. What was the coldest March on record?

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  16. >>Anonymous said... What was the coldest March on record?

    For Winnipeg, coldest March since records began in 1872 was -16.1C in 1899. It's the only March on record with every day below freezing.

    To put that into perspective, that month was 5C colder than the March we just had. Brutal.

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  17. Rob is there any indications that we will start seeing more normal temperatures in the next 20 days? We have been stuck in this cold pattern pretty much all winter, and am hoping our next cooldown is the last of the winter. Any idea on when it will warm up enough to melt the snow and stay that way?

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  18. Rob,

    What are the latest indications as far as the possible change in weather pattern next week? Is there hope for Spring after all?

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  19. Re: any signs of a pattern change.

    I'll just re-post my comments from a couple days ago. Thinking remains the same..

    (From March 31st..)

    Below normal temps continue this week, and then some hopeful signs that we may be turning the corner next week into mid April. AO index, which has been persistently and abnormally negative for much of March, is finally trending upwards and actually progged to go positive by mid April. This would mean a greater frequency of milder Pacific airmasses coming across the southern Prairies, and less arctic airmass incursions. Result will be a more sustained period of melting temperatures starting next week, with a quicker melt of the snowpack, provided we don't get any surprise snowstorms before then. Keep in mind that average high temperatures in Winnipeg in early April are +5C, rising to +10C by mid April, and 14C by the end of April. That of course is due to a loss of snow cover normally by this time. Let's hope models aren't being fooled by climatology.

    My 40 cm snowpack on March 31st is the deepest snow cover for this late in the year since I moved here in 1998. Even 1997 had less snow on the ground at this time (25 cm), until that massive April 4-7th blizzard dumped another 45 cm of snow. Last comparable year that was this white at this time of year was 2009 when I had 30 cm snowpack on April 1st. Snow cover was gone by April 13th that year.

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  20. Euro continues to indicate around 2-4 cm of snow for Winnipeg late Friday through Friday night, while the NAM has also come onboard with about 4-5 cm for Winnipeg Friday night. GGEM still shows snow missing Winnipeg to the south and west, but significant amounts noted over SW MB with 10-15 cm possible Friday afternoon into early Saturday. GFS also takes snow mainly along and south of US border with nothing for Winnipeg. All models have trended colder now, with an all snow solution. Putting all this together, main snow threat will be from southern SK through SW MB and southern RRV into North Dakota, with the chance of some snow clipping Winnipeg.

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  21. Storage shed on fire at Canad Inns Stadium. Visible from Pembina and Bishop on the CBC cam. Reminiscent of the Speedway fire in October of last year. Mirror on my name.

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  22. The current RAP has about 5cm of snow for Wpg today! Likely not.

    CMC Ensemble still has below normal temperatures for the next 16 days.

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  23. Hmmmm....-2 to -3 across the city right now as of noon with strong south winds. Gonna be quite a stretch to get to plus 3 or plus 4 here today i'd say but we'll see what happens when winds shift to westerly at some point this afternoon.

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  24. Quite the variation in wind speed out there right now. Anywhere from less than 10 to over 60 km/h just around Winnipeg.

    http://imgur.com/s9kzR8B (or click name to view)

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  25. Accuweather is back to 6-12 cm for friday. Weather net is 1-3cm and EC is 60% chance of flurries. Are models flipping back and forth?

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  26. Daryl..

    Models have been trending a little northward on the system for Friday-Saturday.. but the bulk of snow still expected mainly south and west of Winnipeg. For Winnipeg, looks like clouds will increase Friday with some snow developing later Friday through Friday night into Saturday morning. At this point, I'm thinking about 2-5 cm possible for Winnipeg with 5-10 cm over SW MB into the southern RRV. Will keep you posted if there's any change in that track..

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  27. Well, so much for turning the corner temp wise next week. Winter weather is forecasted for a good chunk of next week as well and if that ain't enough we'll see more snow tomorrow into Saturday just too add more snow to the large snowpack we have already. Pretty soon we'll be setting record lows....it's coming.
    This is about as bad as it can get here for this time of the year. I see E.C. is forecasting plus 5 next Wednesday but not so sure. Weren't they not forecasting plus temps for next Monday and Tuesday as well in the last couple of days. I mean when you are still getting temps in minus double digits around minus 20 in the second week of April like it's forecasted too next week, that doesn't sound like the definition of turning the corner. I guess we'll have to wait even longer yet for a change if it happens.

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  28. Rob, does the EURO model only perform better greater than a few days out as opposed to a short term forecast since its a global model?

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  29. I dont have official verification stats to say for sure, but in my experience, the Euro is a superior long range model, but in the short term, it doesn't outperform short range higher res models. That's not to say it can't also perform well in the short term, it's just that it doesn't have the advantage like it does in the longer term. Again, that's just my personal assessment... I don't have solid verification stats to say for sure.

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  30. >> Anonymous said.. I see E.C. is forecasting plus 5 next Wednesday but not so sure. Weren't they not forecasting plus temps for next Monday and Tuesday as well in the last couple of days.

    Those optimistic plus temperatures have usually been on the day 6-7 forecasts, which seem to have a bias towards climatology (i.e. "normal") The Day 6-7 forecast comes from the Canadian global ensemble system, but if you look at the output from SpotWx, there's no plus 5 showing up for Wednesday, but more like an average closer to 0C. So I suspect those Day 6-7 forecasts are being tweeked or adjusted towards climatology, which is resulting in those optimistic plus forecasts (note that normal highs are near 10C by mid April for Winnipeg).

    That being said, we've GOT to rise above freezing at some point! I'm still hoping those positive AO index forecasts are right and we start seeing a pattern change around mid April.

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  31. Snowfall estimates for Winnipeg up to 7 am Saturday from latest model runs. Snow generally starting in Winnipeg late afternoon continuing Friday night into Saturday morning.

    RGEM ........ 3 cm
    GGEM ........ 4 cm
    NAM ......... 6 cm
    GFS ......... 3 cm
    EURO ........ 3 cm

    Snowfall ratios look like they'll be close to 10:1 given temps just below freezing.

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  32. Had a look at that forecast.io site again. It's saying -3C 'right now' for Winnipeg. However both The Forks and the airport are -6C. It also says Mostly Cloudy right now. But the current METAR is SKC, not a cloud in sight.

    Gotta wonder where they get their data.

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  33. Regarding the Euro (ECMWF) this article compares the quality of various models. It does out-perform all other global models.

    http://cliffmass.blogspot.ca/2012/03/us-fallen-behind-in-numerical-weather.html

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  34. Rob Do you have any idea when the greenland high pressure system will start to break down? Also would the AO contribute to warmer weather if it goes positive? I and I bet many others are wishing for spring!

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  35. Mike.. If the AO index forecast is correct (i.e going positive), that would really help to break down that blocking Greenland high by mid April. Until that happens, we're stuck in this abnormally cold pattern.

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  36. thanks for share..

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