Monday, February 29, 2016

Cold end to mild winter.. warmer weather returns by weekend

It was a bit of a shock to the system this morning as Winnipeggers woke to -25C temperatures and windchills close to -40.. readings that have been relatively rare this winter. The cold snap was ushered in by an Arctic cold front that slipped through southern Manitoba Sunday night bringing about 3-5 cm of fresh snow, along with gusty north winds to 70 km/h that caused poor visibilities in blowing snow and led to many highway closures last night. Brighter, calmer weather is in store today, but temperatures will remain well below normal with highs only in the mid minus teens and lows tonight back in the -20s. The good news is that the rest of the week will see a moderating trend with temperatures climbing steadily each day this week. Highs by Friday in Winnipeg will be rising to -3C and above 0C over the weekend.

Winter of 2015-16 is 9th mildest on record in Winnipeg since 1872

Winnipeg temp summary since Dec 1st
About 3 out of every 4 days was
above normal
Despite the cold end to February, the month finished 2C above normal at -11.1C, our 6th consecutive month above normal.  The month capped off a mild winter in which all 3 months were above normal. In fact, the 3 month period of Dec-Jan-Feb finished as the 9th mildest winter in Winnipeg since 1872 with an average temperature of -11.3C (normal -14.3C)  The strongest El Nino in the past 50 years was a prime reason for the mild winter, helping to bring more frequent and persistent mild airmasses from the Pacific, while minimizing intrusions of Arctic airmasses from the north.  The result was a fairly tame winter for southern Manitoba, with 3 out of every 4 days averaging above normal. In Winnipeg, there was only one day with a temperature of -30C or colder (-32.3C on January 17th)  A normal winter would see at least 12 such days. Snowfall has been slightly above normal in Winnipeg, mainly due to a snowy week in December in which 41 cm of snow fell from the 16th to 23rd.  As of Feb 29th, snowfall has totalled 101 cm in Winnipeg, about 17 cm more than average to the end of February.   

 

17 comments:

  1. Been hearing rumblings of a big warmup this weekend into next week for our neighbours south of border.

    Rob, is the big warmup in the cards for us here in Southern Manitoba as well?

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    1. Yes it's looking that way. We won't be reaching the balmy temps like further south where's there's no snow cover, but we'll likely be above freezing by Sunday into at least mid week. That will help reduce our snowpack especially to our southwest where's it's meager already. I'm hoping that the mild weather will last here through mid March to help substantially eat away our 30 cm snowpack in Winnipeg and the RRV. Once we lose our snowcover, we can really benefit from those warmer airmasses.

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  2. Confidence seems quite high that our Spring will be warmer than normal.

    Rob, what are your thoughts on that? Do you Agree or disagree?

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    1. I'm leaning that way. There's very little snow cover to our south and west.. which will help to bring in warmer air earlier. The sooner we can get rid of our snowpack, the faster we can warm up.. So far, it's looking positive that a warmer pattern will be setting up for March over central and eastern North Anerica. Here's hoping..

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  3. Looks like another shot of snow coming through RRV on Friday with 2-4 cm possible, mainly from 8 am to 2 pm or so. Not sure why current forecast for Friday in Winnipeg has no mention of snow.. all guidance pretty much on board with some snow that day.

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  4. Rob, are you refering to EC forecast for Friday? If so, they are not reliable for forecasts more then a couple days out, never have been. It is unfortunate because there forecast is the one that usually always gets publisized in the city. Both WU & WN to name a few along with others currently have mention of few cms of snow for Friday. Long range through March does look relatively mild, but potentially unsettled.

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    1. EC's forecast is the only one not mentioning snow for Friday. All models hinting at some snow moving into southern MB overnight Thursday into Friday morning ahead of a clipper system tracking through southern MB. May not be much here in the city.. perhaps a cm or two, but the forecast should at least mention the possibility of some snow that day given the model consensus.

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  5. That drives me bonkers when EC says sunny.
    Why is that? WN, Accurate weather and weather underground all show snow. Do they all use the same model?

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    1. That's the odd thing.. even EC's own model (GDPS) shows some snow for Friday, so the forecast is not even consistent with itself. They do some post processing of model data to take biases into account, but to go from measurable snow to "mix of sun and cloud" seems a bit extreme.

      I did notice that the updated forecast now shows a 30% chance of flurries Thursday night.. which is hinting at the snow moving in by Friday morning.

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    2. So now the forecast calls for a 60% chance of flurries Friday... which is better than "a mix of sun and cloud". Again, looks like a band of snow pushing in over western MB after midnight Thursday moving into the RRV Friday morning. Not a lot of snow, but amounts of 2-4 cm possible in the main band.. 1 or 2 cm on the edge of it.

      Meanwhile, the forecast for next Tuesday is "Sunny" as a fairly significant storm system moves up over the northern Plains with a messy mix of rain or snow over southern MB. That's the problem with putting forecast production on auto-pilot with no human intervention to correct it when it goes off course.

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  6. After that shot of snow Friday morning, we warm up on the weekend with a good melt Sunday and Monday. Next system to watch moves in on Tuesday.. a fairly strong storm system tracking up over the Dakotas bringing in a messy mix of rain and wet snow, changing to all snow by Tuesday evening.

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    1. Rob, Would this be a potential Colorado low type storm? as unfortunately March is known for these.

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    2. It's more of a hybrid Colorado low - Montana clipper type system that merge to track through the Dakotas into Minnesota. At this point, it doesn't look overly intense mainly because there isn't a lot of cold air to inject on the backside of it to really intensify. But something to watch.. precip type will be an issue as the RRV will be the dividing line between rain to the southeast and snow to the northwest.

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  7. This Friday marks the 50th anniversary of the Great Blizzard of March 4 1966 in Winnipeg and the RRV, one of the worst blizzards ever to hit this part of the world. 35 to 50 cm of snow along with winds of 80 to 110 km/h produced massive drifts that paralyzed the city and valley for several days. I will be posting a special blog post on the blizzard tomorrow.

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  8. No surprise.. EC now calling for about 5 cm of snow overnight into Friday.

    Also, models are bringing in that messy weather next week a little earlier, with rain developing Monday afternoon changing to snow overnight into Tuesday.

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  9. As far as that +10C for Winnipeg on Sunday.. not likely for us. +10C is likely over downslope and snowfree areas southwest of Winnipeg (like Morden, Melita, etc) but Winnipeg will likely be more like +5C or so thanks to our extensive snowpack here.

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