Tuesday, November 24, 2009

Sliding towards normal..

It was another pleasant day of sunshine and above normal temperatures over Winnipeg and the Red River valley, but things will be cooling off Wednesday and Thursday, with colder weather likely for next week. Still, temperatures are forecast to remain above the normal high of -5C this week, before cooling off to more seasonable values next week. The return of colder air will also increase the chances for some precipitation, likely in the form of flurries or snow over the next few days. For tonight, some light snow is possible mainly over SW Manitoba with some flurries possible over much of southern MB Wednesday as brisk northerly winds pump in colder air. The next chance of precipitation will be Friday as a low pressure system moves through the Interlake spreading an area of snow mainly north of the low, mixing with some rainshowers to the south. Behind this system, colder air is expected for the weekend into next week with a possibility of some snow Saturday into Saturday night. Winnipeg has not seen any measurable precipitation since the 1st of the month, but the dry streak will likely come to and over the next few days as colder and more unsettled weather moves in.

21 comments:

  1. As of today, Winnipeg's monthly mean temperature stands at +2.0C.. which would be a record for November. However, it looks like we're going to lose about 1 degree off that average over the next 6 days, which would take us down to 3rd or 4th warmest. We can still take top spot honours if things aren't as cold as currently projected, but at this point, it's looking like it's going to be tough to do. We'll see what happens..

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  2. I'm really quite stunned that we may NOT have the warmest November after all!

    I thought for sure we had that one in the wraps!!!

    Is that colder air really going to take that big of a bite out of our average!!!

    Well just got home from work and got a dusting of snow on the ground! Maybe 1mm of melted precip!

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  3. Dan I took out the calculator and came up with this. One more Warm ember month should do it.

    Two of the warmest months in our history September and November plus one more somewhat typical 21st Century December may result in an above average MEAN Temp for the year.

    This Year to Nov 24 the Mean is .55C less than Normal at EC and .08C greater than NORM at RobsObs

    At EC it will take an Avg of 4.9C greater than Mean for the next 37 days. That would be equal to ECs Forecast for the rest of November plus a Mean December Temp of -8.73. Normal is -14.4..

    Decembers In 02, 03, 05,and 06 were all within 1.0C 0f this. At RobsObs they were all warmer than this as was 2001

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  4. As of 10pm its -11C at the airport, -4C at the Forks and -5c at Robsobs. Can someone explain to me why the airport is ALWAYS so much colder, especially in the evening and overnight? Has it always been this way? I have never noticed this until the past couple years.

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  5. The Forks and Rob's stations benefit a lot more from the urban heat island effect than the airport, which is right on the outskirts of town in the middle of a very exposed field.

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  6. The airport has a cold bias in clear skies and a light northwest flow due to cold air drainage off the open fields on the city outskirts. You'll notice this cold bias is not there when there's a light south or east wind which brings milder air from the city core over the airport.

    This shows how temperatures can vary greatly across the city based on proximity to the city and wind flow.

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  7. That dusting of snow yesterday was not enough to measure at the airport, so officially we still have only 0.5 mm of precipitation this month, and our dry streak now stands at 25 days.

    Meanwhile, another 70-100 mm of rain across western Vancouver Island yesterday, including Pt Alberni which picked up another 85 mm. They are now over 800 mm for the month, and will have more in the next few days. Wow.

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  8. Does that dusting of snow qualify for the ROBSOBS POLL Question?

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  9. Will any of the current coastal rains show up as Prairie snow storms if much of our winter snow originates in the west.

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  10. I would consider that dusting of snow in the "few flurries" category. As far as getting that west coast rain as snow here, consider that we're going through our driest November on record, while the west gets deluged nearly every day. That rain is falling mainly on the coast, and drying up as the systems move east.

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  11. Does anyone happen to know what the driest overall month in Winnipeg's history is?

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  12. Wow what a drastic diffenece in forecasts between EC and Weather Net. WN is calling for 20+ cm of snow between monday and thursday and EC is just calling for a 30% chance of flurries on Tuesday.

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  13. Daryl
    Sometimes you have to wonder where The Weather Network gets their information from!!!

    As it looks now I would say there is a chance of accumulating snow around that time frame but 20 cm is a little far fetched!!!

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  14. Driest month on record at Winnipeg airport was April 1980. Only a trace of precipitation recorded the whole month. No measurable pcpn between Mar 27th and May 5th (40 days) That was an extraordinarily dry spring with only 21 mm of pcpn recorded in the 3 month period of March, April and May.

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  15. GFS is showing a rigorous clipper system moving through southern Manitoba mid week next week with some accumulating snow possible along with strong winds and falling temps. GLB model also hints at the development of this clipper system over southern Alberta by Monday. We'll have to see how this develops but right now, all we can say is the potential is there for some accumulating snow for the beginning of December.. but it's too early to say how much.

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  16. daniel p

    It's funny how sometimes WN gets it right on but the forecasts between the two agencies on this forecast may as well be from another planet. ha

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  17. I didn't see Rob's post about the clipper system. I guess that's where WN is getting that info and EC is not believing the GLB model or haven't looked at it yet or maybe don't look at it.

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  18. Latest GLB model tracks clipper system next Tuesday from southern Alberta towards the Grand Forks area bringing a swath of snow across southern MB. ECMWF shows a similar solution. GFS is further north with this system, bringing snow mainly through central MB. GLB ensembles show a high degree of uncertainty with the track of this system, with solutions ranging from the central US Plains to northern MB. Suffice to say that models will have to come more in line before we can speculate how much, if any, of the white stuff we'll see next Tuesday.

    Until then, it's looking dry over southern MB with minimal chances of measurable precipitation through the end of the month. If that's the case, this will go down as the driest November on record in Winnipeg with only 0.5 mm total pcpn at the airport. (current record driest is Nov 1976 at 0.8 mm)

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  19. Those couple of cold nights that we have had really knocked down the mean monthly temperature down!

    1.4 C mean as of the 26th of the month.

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  20. It looks like that clipper system could also be packing some strong winds also!!!

    So this could actually be called our first "storm" in quite some time!!!!

    BRING ON THE SNOW!!!!!!!

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  21. Latest GLB run has shifted the track of Tuesday's clipper further north through the Interlake, coming more in line with the GFS which has been fairly consistent with a track to the north. ECMWF has shifted a little further north as well, although not as far north as the GFS and GLB. Consensus is suggesting bulk of snow with this clipper will fall north of Winnipeg through the Interlake, but Winnipeg and the RRV will likely see some accumulating snow out of it on the backside.. maybe 2-5 cm.

    One thing they all agree on is an end to the above normal temperatures behind the clipper for early December.

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