Friday, May 25, 2012

Late season snow blankets parts of western MB

Photo submitted to The Weather
Network shows enough snow to
build a snowman in Russell, MB
May 25 2012
An unseasonably cool airmass combined with moisture from a trough of low pressure over western Manitoba brought a late season snowfall to parts of western Manitoba and eastern SK last night. A cold rain started last evening then changed to wet snow overnight with a few cm of slushy accumulation over the Riding and Duck Mtns and areas near the SK border.  Dauphin and Swan River had a coating of wet snow while 4 cm was recorded in Rossburn, and 4-7 cm through Russell and Roblin MB.  Kamsack, Yorkton, Melville and Regina SK also recorded some wet snow last night.  Snow this late in the year is unusual, but not unprecedented over southern MB, especially in the higher elevations of western MB. Just 3 years ago on May 15th 2009,  the Dauphin area was hit with 20-30 cm of snow from a late season storm. On May 31- June 1 1985, Dauphin and area recorded about 5 cm of snowfall (same day as the Barrie tornado outbreak in southern Ontario). On June 5-6 1901, 5-10 cm of snow was reported in the Turtle Mountain area and parts of western MB.  In Winnipeg, the latest measurable snow on record was 0.5 cm on June 8 1877, with a high of only +5.6C that day.


  1. Tricky forecast tonite for Winnipeg.. visible satellite image shows clouds looking pretty cellular and clearing line steadily moving southeast (about 150 km in the last 7 hours). NAM sticking to its guns in stalling out the low clouds thru at least 1 am for Winnipeg. Breaks show up between 1 and 4 am.. but model regenerates low clouds by dawn. That scenario is possible since the high looks to stay generally north of our region.

    Other issue is midlevel clouds that are right now along the N Dakota/ S Dakota border. These will advect north and stall out along the southern RRV between 4 and 7 am.. NAM even show virga occurring just south of Winnipeg.

    In terms of precipitation, still looks like upslope areas of southern Saskatchewan and NW Ontario will be favored for heavy rain. Models show good dry slot just to our south with very little QPF.. we'll have to watch if it shifts north with subsequent runs.



  3. Warnings
    City of Winnipeg
    3:29 PM CDT Friday 25 May 2012
    Frost warning for
    City of Winnipeg issued

  4. Frost warning issued for much of southern Manitoba including Winnipeg. Breaks in cloud cover showing up just north of the city which gives concern for at last partial clearing tonight along with decoupling winds allowing temperatures to drop towards freezing. City core should be safe from frost but suburbs and areas north of the city would be more prone. Not a slam dunk.. but risk is there. Less of a frost threat as you head south.

  5. Tornado warning in Southern Quebec! Some really nasty cells in the region.

  6. Skies partially cleared this evening across Winnipeg/RRV but now we extensive high/mid level clouds over Montana and ND spreading in across the border. That will likely minimize frost threat along and south of the TransCanada, so we may escape with just a risk of patchy frost around Winnipeg. Better chance for frost through Interlake and Riding/Duck Mtn areas where skies will be clearer longer and winds light in the ridge.

  7. Our weather may be poor tomorrow with rain and wind, but not like Maple creek that could get 20- 30 cm of snow!!

  8. We were in Yorkton the night of the heavy snowfall in 2009. What a surprise! It was magical. We found 30 cm of wet snow on the car after we emerged from our second-rate hotel. I wish we could have stayed around all day, but by the time we reached Saskatoon it was sunny, warm, and dry.

    Based on what I have learned on this web site, last night I figured that with the cloud cover, high humidity, and gentle breeze frost was unlikely around my house, so I went without protection. I wasn't disappointed.

  9. An F1 tornado hit Mirabel, Quebec last night! That is the second tornado confirmed this year after the F0 in Orono, Ontario just a few days ago.

  10. Cloud cover pretty much nullified frost last night until you got north of a Riding Mtn-Gimli-Bissett line where frost was more evident with thinner cloud and light winds.

    Now that we have the snow and frost out of the way, time to concentrate on the rain! Models still in agreement that we should see a pretty solid area of moderate to heavy rain move through southern MB overnight through Sunday with a chance of some embedded thunderstorms. According to model concensus, rain should start in Winnipeg overnight between 3 and 6 am, becoming heavy at times Sunday before tapering off in the evening. Rainfall amounts from the GEM are around 20 mm, NAM 30 mm, Euro 15 mm, and ensemble average about 10-15 mm. GFS is lightest at only 5 mm. Precip amounts will be contingent on convection blowing up ahead of the warm front overnight, so amounts from the GEM and NAM may be overdone if convection doesn't fire up as extensively as currently predicted. Keep an eye on radars south of the border to monitor progress of convection tonight.

    Other issue Sunday will be strong east to northeast winds of 40 to 60 km/h Sunday and low teen temperatures which will make it a generally unpleasant day. Bad timing for the Teddy Bears Picnic.. but as always, they'll make the best of it. (kids still have fun, it's the parents who'll grumble.. :)

  11. NAM is overdoing convection overnite and tomorrow morning in my view.. 750 J/Kg of CAPE barely brush the Emerson area.. and nose of main LLJ will be in Minnesota. That is where it is more likely a large convective complex will form, maybe affecting SE Manitoba and NW Ontario by morning.

    Another area of heavy precipitation as mentioned before, will set up along the deformation zone of the upper low.. probably from the riding mtn area back thru the Cypress Hills of Saskatchewan. In between the two areas I think we will just see some general rain and showers with amounts up to 10 mm for Winnipeg.

    Dry slot apperas to move into RRV by afternoon tomorrow.. I would expect occasinal light rain or drizzle. More significant rain will be from interlake back thru SW Manitoba, and also in NW Ontario out towards Atikokan..

    Some differences between RGEM and NAM for placement of surface cold front and weak low.. NAM is further east and has any surface based convection popping well into Minnesota, wheras RGEM showing Grand Forks and south possibly in a warm sector early tomorrow afternoon with potenital for severe storms.. some of which might brush SE Manitoba. According to NWS this solution has support from the ECMWF.. I guess we'll see.


  12. Second tornado F0 confirmed in Quebec.
    A teenager in Ottawa also died after being hit by lightning.