Sunday, April 23, 2017

Oh no! More snow!

It will be back to winter like weather over southern Manitoba Monday as a storm system intensifies over the Dakotas and tracks into northern Minnesota by Monday night. A band of snow is expected to spread into the Winnipeg area by mid morning Monday, with snow intensifying through midday into the afternoon before tapering off Monday evening. Snowfall accumulations will be tricky as some of the snow will be melting on impact, and there will be milder air over southeast MB that will change snow to rain for awhile over parts of southeast MB. For Winnipeg, precipitation should remain as snow with a good 5-10 cm expected by late afternoon, and perhaps 10-13 cm by the time it ends Monday evening if we get under some heavier bands. The best bet for heaviest snow will be towards the Ontario border where 10-20 cm is possible Monday into Monday night.    

UPDATE:  (9:30 am Monday): Latest guidance and radar indicating Winnipeg will be on western edge of this system with bulk of snow mainly east and southeast of the city. Winnipeg will likely still see some wet snow by late morning into this afternoon, but amounts should be minimal with perhaps 2 cm or less on grassy surfaces. Roads will just be wet. Wet snow may even mix with rain here at times today as temperatures stay above freezing. Heavier snow will be confined just to the east and southeast of Winnipeg in places like Steinbach, Whiteshell and Falcon Lake where 5-15 cm of snow is possible through this evening.  

How unusual is heavy snow in late April? 

Although not common, snowstorms are certainly not unheard of in late April or even May in Winnipeg and the Red River valley. Consider these top 10 late season snowfalls (daily) that have occurred in Winnipeg after April 15th. As the table shows, heavy snowfalls have occurred in Winnipeg well into the 3rd week of May.

TOP 10 LARGEST DAILY SNOWFALLS AFTER APRIL 15  
              (WINNIPEG DATA 1872 - 2016)

1.  29.0 cm ............ May 11 2004
2.  21.1 cm ............ May 1 1967
3.  20.8 cm ............ Apr 27 1966
4.  20.3 cm ............ May 19 1931
5.  20.0 cm ............ May 9 2002
6.  17.3 cm ............ Apr 24 1937
7.  16.5 cm ............ Apr 25 1960
8.  15.2 cm ............ May 20 1882
9.  14.0 cm ............ Apr 19 1996
10. 13.0 cm ........... May 5 1938

In 1958, a full fledged blizzard hit Winnipeg on April 28th with 5-10 cm of snow blown by 80-100 km/h winds along with frigid temperatures of -10 to -13C.

32 comments:

  1. Rob so it looks like Winnipeg is going to get it good with this storm? Looking forward to it! How much precipitation did you get at your place on Saturday. All that snow melted but if we get blasted tomorrow how long do you think the new stuff could stay for? Also it looks like temperatures will be around plus 1. Is that cold enough to sustain snowfall as that is above freezing

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    1. Matthew.. latest guidance now showing Winnipeg getting brushed by this system with bulk of snow mainly over southeast Manitoba (closer to Ontario border) Models have backed off on snow amounts for Winnipeg.. now showing only 2 cm or so of wet snow for us, possibly mixed with some rain. We'll see how this thing develops but at the moment, it appears Winnipeg will be dodging the worst of this. Which is OK by me..

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  2. Well that's unfortunate. I don't know how it can change that quickly when yesterday they said Winnipeg was getting the worst of it. It always seems to miss us either to the west or southeast

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    1. Yeah us extreme weather junkies in the Winnipeg area seem to get the short end of the stick always. I'm somewhat ok with not getting the snow although some interesting weather now would be nice out of the ordinary. What I hate is when the summer storms always miss us. And you're right we always get missed either to the west or southeast. Hopefully this trend doesn't carry over into the summer. I love storms!

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    2. Matthew.. Yesterday most models were showing that Winnipeg would be getting 5-10 cm out of this system, with more to our east. But latest guidance is showing the system is moving a little futher east and not quite as strong, with the heaviest snow mainly east and southeast of Winnipeg (Steinbach, Whiteshell, Falcon Lake, etc) Only one model, the NAM, was indicating Winnipeg would be getting the worst of this system with 10-20 cm, but it was obviously out to lunch and it too has backed off in most recent runs.

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  3. Just trace flurries falling right now with a nasty wind out there. I expect we won't even see any accumulation whatsoever. But yeah we literally always get missed either to the west or the southeast. Mother Nature hates us who live in the city or something like that. Most people think I'm crazy for wanting storms but I absolutely love a good winter storm. And yeah the summer storms seem to always miss us too. However two of the worst storms in years happened last December. We had 2 once in a decade storms in three weeks, that was awesome and I wish we'd see that more often

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    1. Haha yeah I know. People seem to hate/annoyed us who want the storms to hit us. All we want is some interesting, active weather because its what we love. You get far fewer active storms then you don't so why complain about what little storms we do get? Some snow that will all melt by the end of the week ain't hurtin anybody! Although by now I just want warm weather and storms. This snow will be a distant memory in a couple of weeks.

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    2. I enjoy snowstorms too.. but only in season. Once it's April, I've had it with snow (winters here are long enough!) Now I just want sunshine and heat! (and yes, some good thunderstorms to keep things interesting..)

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  4. And they are getting snow northwest of Winnipeg too. Literally we are in the little pocket that's getting nothing. Always seems to be the case. Ugh.

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    1. If it makes you feel better (I know it does a bit for me) according to the models where the hot spot is for the "bulk" of the snow SE of here is only showing maybe 11 cm at the most, which is only twice what we're getting, which isn't a substantial difference IMO.

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  5. Well we definitely got some consistent snow showers for several hours yesterday. Most of it melted in contact with the ground. Any idea how many cm's fell? Though it may be hard to measure cause it all melted. Rest of the week looks very chilly too. A cold night tonight with temperature dropping to -5C with a windchill of -12

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  6. Forecast for Winnipeg tomorrow: "Mainly sunny. Increasing cloudiness in the morning then 40 percent chance of light snow early in the afternoon then 40 percent chance of rain late in the afternoon."

    Back in my day, we'd write this forecast as "Increasing cloudiness. 40% chance of afternoon showers or flurries" Much simpler and to the point, and likely better chance of verifying.

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  7. Rob is April going to finish above average. I can't compare it to the averages because the weather record books website has been down since mid March. Do you have any information on why that site is gone or if it's coming back.

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    1. Matthew.. that site is undergoing some changes, and may be back in the near future. Keep checking for updates..

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  8. Rob, it appears that there are hints of perhaps the first taste of summer late next week into next weekend with Temps possibly reaching the mid 20s. What are your thoughts on this?

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    1. Yeah, models are showing a warming trend for us late week, but they differ on extent and timing. Looks like bulk of the warmth will be mainly over western Canada (AB, SK) this week with some of that warmth pushing east into southern MB by Friday. But it may only be for a day or so over us with temps in the low to mid 20s..

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  9. Looks like temperatures will reach close to the 30C mark in southern Alberta and Saskatchewan. Looks like an extended taste of summer for them. For us we only seem to get one or 2 days of about 21C. Kind of a rip off

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  10. Rob, are there any signs of a warmer pattern over the next few weeks here in Southern Manitoba or will our cool May continue?

    Thanks.

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    1. No real abnormal warmth expected in the near future over southern MB based on current guidance. Warmer airmasses will likely be suppressed mainly south of the US border and over towards the East Coast for the second half of May as storm track sets up over northern US. This would tend to give us generally cooler than normal temps, with occasional warmups ahead of systems.. along with precip events every few days. In other words, a variable weather pattern over the next week or two with near to below normal temps, and near to above normal precip.

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  11. I'm beginning to wonder if dry hot summers are a thing of the past here in southern MB. It's been a long while since we've seen a drought like pattern here.. like we used to get in the 1930s, 60s and 80s. Our last really dry summer was in 2006.. otherwise, summers in the 2000s have generally been characterized by above normal rainfall, with frequent heavy rainfall events. I can't remember the last time we went weeks in the warm season with little or no precip.

    This would be consistent with an overall warmer climate that has an increased ability to hold more water vapour (warmer air can hold more moisture) Airmasses that hold more moisture have the ability to precipitate more frequently, and more heavily. That adds more moisture to the soil, which also helps to fuel more precipitation, which just further enhances the precipitation feedback cycle. In other words, a warmer and more moist climate would tend to reduce the odds of drought.. at least in areas where storm tracks are favoured (like here in the Prairies and across the mid latitudes) where you get the necessary lift to initiate the convective process. I don't know.. just putting it out there.. but that's how our climate seems to have evolved over the past 20 years or so.

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    1. Summer of 2011 and 2012 was pretty dry no? Didn't we go 6 weeks without rain in the summer of 2011?

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    2. Yes you're right.. 2011 and 2012 were dry summers here.. with some good heat (I forgot about 2011 being the driest July on record in Winnipeg) But they seem to be exceptions.. not a trend. Wet summers seem to be more common these days.

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  12. Rob, are we looking a potential significant rainfall Tuesday here in Winnipeg and the RRV? Will thunderstorms also be possible with that system?

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    1. Most models are indicating the potential for 15-25 mm of rain for Winnipeg/RRV Tuesday, with some embedded tstorms possible as an area of convection blows up over the Dakotas Monday night and spreads into southern MB during the day Tuesday. The Euro however is not as bullish, and keeps bulk of convection and heaviest rain south of the border, with only a few mm for Winnipeg/RRV. At this point, all we can say is there is the potential for a soaking rain Tuesday, but still come uncertainty about it. We'll see how models trend over the next 24 hrs.

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  13. Wonder when we're going to get out of this god awful cool dry weather pattern? I remember May's being warmer and stormier that's for sure. Been the trend for May's lately.

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    1. Yeah, warm weather has been elusive for us so far. Only a couple of warm days, otherwise we've been generally near to below normal as of the past week or so. Looks like we warm by the end of next week into the mid-upper 20s.. but it may only be for a couple days then we cool off again. Normal highs are now 20C.. so we really should be hitting the 20s regularly now. Luckily, it hasn't been too cold at night with only 2 days of frost so far this month.. but another one on the way tonight. Trees leafing out nicely though.. so at least it looks a little more like summer.

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  14. Rob could May finish below normal? Since the record books are down I can't see the norms, what is may's average mean temperature?

    Is it just me or are summers cooling down a little but. It seems springs are coming earlier, March's have been bringing big warm spells in recent years, but it seems when we get to April and May we get drenched with rain and cool down. Look at last years freezing April. And the cold April's of 2013 and 2014. May is on a cool down trend too, last year was the exception with one of the hottest mays I ever remember.

    The summers of the 1930's were brutal. I hope we never see a repeat of July 1936, 42.2C high temp, that's scary. It seems like we get less extreme hot days now even though our climate is overall warming.

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  15. Rob did we break a record low this morning? Environment Canada airport data says the old is -3.3 and we hit -3.5. Their data is only 1938-2008 for some reason though. Do you know if we broke a record dating all the way back to 1872?

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    1. Matthew.. the official low this morning at Winnipeg airport was a chilly -4.9C, but not quite a record low for May 19. It got down to -5.6C on May 19 1924 (using Winnipeg records back to 1872)

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  16. That's cold! We got so close I wish we broke the record low. Still that's the coldest May 18th morning since 1924, that's still pretty impressive.

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  17. I'm just curious as to where you get the data now that the records book website is gone?

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    1. You can view daily records for the older Winnipeg weather site (St Johns College) which has data from 1872-1938 at this site:

      http://climate.weather.gc.ca/climate_data/almanac_e.html?month=5&day=19&StationID=3703&period=30&searchMethod=contains&txtStationName=Winnipeg&timeframe=4&month=5&day=19#

      You can compare these records with the airport records to see which one is more extreme for the date.

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