Thursday, January 20, 2011

January thaw spreads over Alberta while Manitoba shivers

A surging mass of mild Pacific air will be spilling over the Rockies into Alberta and western SK over the next few days, while Manitoba remains entrenched in cold Arctic air. Temperatures will rise above zero over much of southern and central Alberta today through the weekend, while temperatures of -20 to -30 prevail over the eastern Prairies. The dividing line between these two distinct airmasses will set up from northern Alberta into western North Dakota, with occasional clippers moving along this boundary bringing bouts of snow that will clip southern MB from time to time, especially over southwest sections. Long range guidance is hinting that this dividing line will shift east into southern MB next week with moderating temperatures and a chance of snow.

In the meantime, be prepared for very cold conditions today into tonight over southern Manitoba as an Arctic ridge builds in. Temperatures this afternoon in Winnipeg will struggle to the -23C mark but the good news is that winds will be dropping off as the ridge builds in, so windchill won't be a significant issue this afternoon into this evening. Temperatures however will plummet into the low -30s this evening as the ridge moves over the red River valley (note this ridge brought temperatures of -35 to -40C this morning over western MB and eastern SK) The coldest temperatures will be this evening then look for rising temperatures overnight as clouds move in and winds pick up from the south. Those winds however will bring increasing wind chills once again, with values near -40 overnight into early Friday morning.

18 comments:

  1. As of noon time:
    -27 C (windchill -41) in Regina
    +1 in Calgary

    Sigh......

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  2. The temperature is colder at Rob's place than at the airport tonight....that's very rare!

    Usually it is the other way around!

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  3. A light south wind will often give the south end of Winnipeg colder temps than at the airport, since the flow is coming off open rural fields south of the city, while the airport is somewhat modified by the urban buildup to the south of the airport. But yes, it doesn't happen too often.

    Lots of -30C readings outside the city this evening.. with a bone-chilling -36C at Marchand in SE MB. I see that Grand Forks has issued their first extreme cold warning for NW Minnesota tonight (temps < -30F, light winds)

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  4. Speaking of cold.. Christopher Burt, author of "Weather Extremes", has an interesting blog entry about the coldest temperatures ever recorded on Earth (click on my name). -30C doesn't seem so bad after all!

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  5. Temperature has crashed down to -34C in Steinbach this evening. Temperature is down to -30.3C at my house, making this the coldest day of the winter so far.

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  6. Looks like I'm bottoming out at -30.9C this evening.. some high clouds starting to drift in from the west should start sending our temperature up the rest of the night.

    Coldest surface temperatures over NW Minnesota and SE MB really shows up well on the IR satellite imagery this evening..

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  7. This morning weather a few miles south and east makes me feel warmer as well
    Time MN
    -15Z -32.8 F at Ely
    -14Z -36.4 F COOK
    -11,12Z -41.8F BIGFORK Weather Bomb Ctr
    -10Z -43.6F Intl Falls
    -04Z -34.6 F at Fosston

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  8. A high of -4 C on Sunday for Winnipeg! I highly doubt that!

    I believe that when I see it!

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  9. Yeah strong south wind with outflow from frigid arctic high to the east so definately will be colder in the valley on Sunday. New extended automated forecast for Sunday has high now of -7C for Winnipeg. Even that seems too warm.

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  10. Rob

    I see EC is advertising a fairly warm temp for sunday as a high but if it does get to -7 will it actully drop back down to -29 at night. That is what EC is saying right now

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  11. That -29C low would actually be for Saturday night and likely midnight as temperatures should be slowly rising overnight Saturday.

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  12. anonymous is correct.. that low of -29c was forecast for Saturday night, with temperatures rising by Sunday morning as the southerly winds and clouds increase along with some snow. However, as anonymous mentioned, that -7C for Sunday seems very optimistic given we stay with a brisk south wind up the valley much of the day. Highs of -10C or so more likely, which will feel even colder with that wind. (click on my name to see NAM sounding for Winnipeg for 6 pm Sunday evening.. note the warm air aloft, but the cold air trapped by the south winds near the surface) We have a better chance of seeing -7C Sunday night into early Monday as the next clipper moves across southern MB bringing in some of that milder air to the west.

    Remember.. our warmest days in the winter in Winnipeg are when we get a west or northwest wind advecting mild Pacific air over Alberta and SK into southern MB. A south wind in the winter does not warm us up as much since it usually is tapping retreating arctic air to our south and east, and maintains cold air trapped in the valley. In addition, the funneling of the south wind in the valley adds to the wind chill.. making it feel even colder.

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  13. Nice write-up from NWS Duluth on the extreme cold in northern Minnesota last night.. -46F at International Falls tied all time record low at airport there (although they hit -55F in 1909) Click on my name for details..

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  14. Is it MBs turn tonight.-37 Beausejour , Ericsdale and -39 at Fisher Branch.

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  15. -36C in Steinbach this morning, coldest day of the winter so far.

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  16. -35 C at the Winnipeg airport this morning!!!
    Don't you just love Winter in Southern Manitoba.....

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  17. Nearest I can find to -40 in the Province is Fisher Branch at -39.6.

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  18. A high of -4 C on Sunday for Winnipeg! I highly doubt that! I believe that when I see it!

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