Wednesday, February 08, 2012

We interrupt this mild winter for a brief cold snap..

The above normal temperatures so far this month will give way to a couple of days of bitterly cold weather as a sharp cold front crosses southern MB early Thursday. Northerly winds of 30 to 50 km/h will usher in much colder air from northern MB Thursday, with 8 am temperatures around -10C falling to -22C by 6 pm along with windchills of -35 (see forecast temperature graph) Temperatures will continue to fall Thursday night reaching -30C by Friday morning, along with windchills near -40. Friday will be bright and sunny but very cold, with highs only in the minus 20s . Fortunately winds should be light Friday as high pressure builds over the region. The cold snap is expected to be short lived however as moderating temperatures move in over the weekend into next week.

14 comments:

  1. If we somehow go the entire winter season and NOT hit -30 C here in the PEG, will that be a first????

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  2. Rob!
    Have you noticed the snow sculptures around town are looking pretty rough. Sounds like they had to truck in some snow or make some artifical white stuff. Having grass exposed around the carvings also make it look odd :-(

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  3. daniel..

    As far as I can tell, there's been only one winter since records began in 1873 that Winnipeg didn't hit -30C or lower. That was the winter of 1930-31 when the winter's lowest minimum temperature was a -29.4C reading in February.

    Even our all time warmest winter of 1877-78 managed to hit -31C in January (although we never went below -20C in Nov, Dec, Feb or March which is quite extraordinary)

    Our lowest temperature so far this winter has been -28.9C on Jan 18th. We have an outside shot at -30C by tomorrow morning, but latest guidance is suggesting -27C or so.. If we do manage to go the entire winter without a -30C reading, it would be only the second time that's ever happened here, and the first time in over 80 years.

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  4. -28.7 at 7:40am. Is it too late to squeeze off a -30?

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  5. It's official we have hit -40C at 820 am!

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  6. Mike where did you get the "It's offical -40. It doesn't look like Winnipeg got that. Temps were already moving up as of 8:00am with a low of -29.

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  7. Mike , yes we did hit -40 C WINDCHILL, "feel like" temp at 8:00 this morning!

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  8. Typical mistake. Wind chill is not the same as air temperature so we did not hit "-40C" as Mike stated. Also, wind chill is not reported in degrees C as the units cancel out in the equation for wind chill, leaving a unit less value.

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  9. Yes, windchill is NOT a temperature.. but a COOLING RATE expressed in terms of an equivalent temperature. The general public (especially the media) has a perception that the ACTUAL temperature is -40C which is understandable, but is incorrect. Basically, windchill is saying that the actual temperature is -28C, but with the wind, it feels like your body is losing heat as quickly as if it was -40C under light wind conditions.

    But even this comparison between temperature and windchill is flawed. Most people will tell you that -40C with a calm wind is actually not that uncomfortable, and that -28C with a 20 km/h wind (producing a -40 windchill) feels worse. That's because your body's internal 37C heat engine produces a thin layer of warm air around your skin. That thin layer of warm air actually reduces heat loss (to a point) to make you feel more comfortable in cold conditions. If there's sufficient wind (say, over 10 km/h) then that protective microlayer of warm air around your skin is removed, which allows more rapid heat loss from your body, making you feel colder more quickly.

    This is why I think it's very misleading and scientifically invalid to be advertising windchill values when winds are light (less than 10 km/h), because in those cases, accelerated heat loss from your body is not an issue. In fact.. one can argue that when winds are light, it actually feels WARMER than the actual air temperature due to that protective layer of warm air surrounding your skin and reducing heat loss.

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  10. Official low this morning at YWG airport was -28.9C, tying our coldest reading of the winter so far also reached on Jan 18th. Our non -30C streak continues!

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  11. I apologize for the confusion everyone the temp wasnt -40 at 8 am the windchill was.....

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