Monday, December 30, 2013

Coldest December temperature in 80 years possible Tuesday morning as 2013 ends with brutal cold spell

Low temperatures from the
RGEM model valid Tuesday
morning Dec 31 2013.
Note pockets of -40C temps
across southern MB. 
Baby it's cold outside.. even for hearty Winnipeggers.  2013 is ending with a brutal cold spell with temperatures some 10-15C below normal for the end of December. Winnipeg has hit lows of -35C the past two mornings, with highs only in the minus 20s. And the worst is yet to come as the peak of the cold spell moves in by tonight. Today will be bitterly cold with highs barely nudging above the -30C mark. Luckily winds will be light to offset the frigid temperatures somewhat. Tonight however with clear skies and a light northwest wind, temperatures will plummet towards the -40C mark by Tuesday morning, and -50 with the windchill.. dangerous cold that can lead to frostbite within minutes, or deadly hypothermia if exposed to the cold for a prolonged period without proper clothing. If Winnipeg hits -40C early Tuesday, it would mark the first time the city has hit the -40C mark in almost 7 years (a low of -41.7C on Feb 5 2007)  It would also mark the first time in 80 years that Winnipeg has hit the -40C mark in December, a feat last achieved on Dec 28 1933 with a temperature of -41.1C. This shows how unseasonably early this cold snap has been, with similar cold spells more typical here in January or February.  The cold weather is expected to persist though New Years Day and Thursday, before another Alberta clipper brings in snow and moderating temperatures Friday. The respite however will be short lived as we get back into below normal temperatures again next weekend into next week. Bundle up and stay warm folks!  Bitter cold is here for awhile!

UPDATE Dec 31: Official low at YWG airport was -37.9C this morning, which makes it the coldest December temperature in Winnipeg since 1933.  The -37.9C low this morning just edges past the -37.8C readings recorded on Dec 31 1967 and Dec 31 1973. It was not a record low for the day however, which still stands at -38.3C on Dec 31 1884.  (Click here for list of daily December temperature records for Winnipeg since 1872)

42 comments:

  1. And the coldest time of year is yet still a few weeks away. Models still consistent with very high probabilities of below normal temperatures. Concerning to say the least.

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  2. Rob, did we get warmer than - 28.3C today at the airport? I think that was the record for the coldest daytime maximum.

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  3. Bottoming out to -40 C will be contingent on high clouds which will try to stream in from the northwest over the surface ridge. Models suggest the potential for some high, thin clouds (above 500 hPa)to overspread Winnipeg by about 3-4 AM. Although not ideal for efficient counter-radiation, it may be enough to prevent temperatures from absolutely bottoming out. Thicker, mid level clouds are progged to be held off SW of Grand Forks all night long.. setting the stage for a sharp temperature gradient from SW to NE by morning.

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  4. Kinda starting to look like - 40C is becoming a stretch for us tonight. Temps no dropping at all at YWG Airport thus far tonight. Must be because of that light Southerly flow currently observed at the Airport as opposed to a light NW flow.842

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  5. Yes, light southerly winds this evening are keeping temperatures from diving this evening, but winds are forecast to turn more NW after midnight which should drop the temperature more rapidly at the airport. I still think we have a shot at -40 by morning.

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  6. Only forecasting a high of -31 tomorrow! When was the last time we had a daytime high -30 and less?

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  7. I think reaching -40 C at YWG will be contingent on completely clear skies.. as high clouds try to stream in over the surface ridge. Although models show the thickest, midlevel cloud being held off SW of Grand Forks during the night.. they indicate the potential for at least some broken high clouds (above 500 hPa) to overspread Winnipeg around 3/4 AM. If that scenario plays out, it may enough to keep the temperatures from absolutely bottoming out. There will definitely be a strong SW to NE temperature gradient by tomorrow morning.. with -40 C readings over the Interlake, Whiteshell, and Sprague region likely.

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  8. Winds have started to turn into the NW at YWG airport as of 1030 pm, which will tap some of that -32 to -35C air just NW of the city. I suspect the 11 pm temperature from YWG airport will show a notable drop.

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  9. Rob, I know you aren't into long term forecasting. But can you help what is causing this prolonged cold snap ? Is there some sort of blocking pattern responsible? What would we need to see happen to switch to a more moderate pattern and how far ahead might there be indications of that ? Sorry for so many questions but I'm getting weary of this

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  10. Manitoba's literally in a sea of red with all of these wind chill warnings!

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  11. Amazing the difference the wind direction makes on the temperature relative to your location in the city. Earlier this evening with a light south wind, the temperature at my station dropped to -34C (open fields to my south) but stayed steady at -30C at the airport (south wind off the city). Now that the wind direction has switched to northwest, the temperature at the airport has tanked to -34C (off open fields to NW) while my station has bumped up to -31C (NW wind off west end of city)

    I doubt I'll be seeing -40C at my site, but it's still possible for YWG airport as winds stay out of the NW the rest of the night into the morning.

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  12. Mark.. You're not the only one struggling with this cold and looking for an explanation. But I'm at a loss to explain it. Obviously there is some sort of blocking pattern going on, but I'm not sure what's causing it. The ENSO pattern is pretty much neutral (no El Nino or La Nina to speak of) and the AO index has been positive much of December which, from what I understand, should have meant LESS Arctic intrusions for us, not more. So why are we blocked? I honestly don't know.. I just hope it gets unstuck soon.

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  13. I heard somewhere thin, newer arctic ice gives off latent heat into the upper atmosphere so i think last winter and this winter is so cold because of a lower temp gradient between the arctic and the equator. Just a possibility

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  14. Didn't quite make it to -40C at the airport this morning with a low of -37.8C so far. We'll see if it drops a little more over the next hour or so. Note the difference in the 2 auto stations at YWG airport. The NC autostation that supplies the YWG hourly data shows an 8 am temperature of -35.7C. The EC auto station (XWG) at the same time is showing a temperature of -37.5C, almost 2C colder! There were some issues noted with the NC autostations having a warm bias with temperatures below -25C, which could be the case here.

    By the way, that -37.8C this morning ties 1973 and 1967 as the coldest December temperature in Winnipeg since 1933. Coincidentally, all 3 occurred on Dec 31.

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  15. Rob and Mark - Here's one possible explanation: "Winter 2013-2014: Sea Ice Loss Locks Jet Stream into Severe Winter Storm Pattern For Most of US"

    http://robertscribbler.wordpress.com/2013/12/10/winter-2013-2014-sea-ice-loss-locks-jet-stream-into-severe-winter-storm-pattern-for-most-of-us/

    or

    http://tinyurl.com/p3slhsq

    I honestly just skimmed over the article, but have heard this explanation before. It may have some merit. But like Rob I don't give out seasonal forecasts because they're wrong as often as not.

    Here's a funny one. Students assessed AccuWeather's 45-day forecasts.

    http://tinyurl.com/ksm78he

    They found that for anything past about 10 days, it was better to simply use the climate normals as your forecast, compared to AccuWeather.

    -Garth

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  16. Thanks SpotWx for the link. That link talks about the increased frequency of blocking patterns in the northern hemisphere due to a weaker jet stream caused by loss of Arctic sea ice. The theory suggests that a weaker jet stream gets "stuck" more often than a stronger jet stream, which makes sense. That's good news if you're stuck under the warm block (as we were from 2011-2012) but sucks when you're stuck in the cold block (as we are now) What this suggests is that global changes due to loss of Arctic sea ice can lead to longer episodes of above normal or below normal weather patterns.. depending if you're under the positive or negative side of the jet stream. I just hope the jet stream can shift and we get back to a nice prolonged above normal pattern again like in 2011-12.

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  17. Updated low from Winnipeg airport.. low of -37.9C as of 9 am. Just edges the -37.8C readings in 1973 and 1967. We'll see if that's the final low or if it drops another few tenths.

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  18. The dewpoint is -40.5 at the airport, so I guess you could say the potential was there for -40, but is possible for the temp to level off with the dewpoint in situations like this??

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  19. SpotWx... that thing on accuweather 45 day forecasts is pretty interesting. It just goes to show how inaccurate the automated public forecasts are. It would be interesting to do the same with each of the following automated public forecasts long range : The weather network, Wunderground, friendly forecast, or whatever other automated public forecast you could think of!

    I wonder if the general public would start using an easy model viewing site like your fantastic SpotWx if they new about these results.

    -Willy

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  20. ROB that 67 new years eve cold snap AsIRecall was preceded by a warm Xmas eve n day This was a feature of many yuletide seasons of 50sand 60s. Makes me wonder why I kept buying air cooled cars.

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  21. Rob, just noticed your link to JJ's blog is actually a link to his "south st. vital weather data" page. You might want to fix that...

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  22. Rob when was the last time we had a daytime high of -30 or less?

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  23. ROB. If that was in error it was appreciated by those who noticed Julien was away Don

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  24. Link to JJ's weather blog has been updated. (http://jjwinnipegweather.blogspot.ca) Some great info there.. and he's coming out with his top 10 weather list for 2013. You can vote for top story as well. Check it out!

    http://winnipegweatherpolls.weebly.com/top-10.html

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  25. Most likely another very cold night coming up. Don't be surprised to see temperatures very similar for Winnipeg again tomorrow morning!!

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  26. Yep, it does not look like we are going to get above -30C at airport today. Not too often you can say that!!

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  27. Willy - Most of the products I show on SpotWx are also fully automated. Only the short-range Meteocode has human input (from smart folks like Rob). However my site isn't focused at the general public so most users understand how to 'interpret' the forecasts.

    But yes, I understand your point. Without giving too much away, something like what you described is already in the planning stages. ;)

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  28. When was the last time we had a daytime temperature of -30 or less??

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  29. A "high" of only -30.4C at YWG airport today.. that's our first sub -30C high since Jan 30 2004 (with a high of -30.8C that day) So today was the coldest "daytime" in almost 10 years.

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  30. >> Anonymous said...ROB that 67 new years eve cold snap AsIRecall was preceded by a warm Xmas eve n day This was a feature of many yuletide seasons of 50sand 60s.

    Dec 31 1967 was also the date of the famous "ice bowl" NFL championship game in Green Bay when the Packers defeated the Cowboys 21-17 in -26C weather.

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  31. Temperature have actually climbed to -30.1C at YWG airport as of 10 pm this evening with some clouds and a light south wind.. so we may actually get above the -30C mark today after all.

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  32. Temperature has nudged above the -30C mark at YWG airport as of 11 pm.. so officially, Dec 31 won't go down as a -30C day after all. Doesn't that warm you up? :)

    Happy New year all! Let's hope for a warmer 2014!

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  33. I hope this won't turn out like 2008-2009, where the cold blocking pattern broke only in September. This December has been eerily similar to that of 2008.

    Are the upper level atmospheric conditions (blocking etc.) similar to December 2008?

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  34. -42C in Gimli this morning. New year, same old cold.

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  35. Andy.. From what I recall, the 2009 blocking pattern was the result of warmer waters over the eastern Pacific that strengthened the west coast ridge, and maintained it for a long period of time before it finally broke down. I'm not sure if we have the same signal this year, but we do have a persistent west coast ridge in place which is not good news for us... as it helps to lock in an upper trough over central Canada which brings greater frequency of Arctic air masses over Manitoba. Note that 2013 has been the driest year on record in central California (only 80 mm of rain in San Franisco all year!) which fits with a strong west coast ridge pattern. I just hope that whatever is maintaining this west coast block is on its way out soon, and we can get back to more "normal" conditions.

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  36. Models are coming in stronger with Fridays system.. showing a fairly intense clipper tracking across southern MB. NAM is the worst of the bunch, showing a good 20 cm for Winnipeg starting early Friday and tapering off Saturday morning. Most other guidance is in the 4-8 cm range at this point. In addition, the system will be giving strong southerly winds ahead of it Friday and strong NW winds behind it Saturday, so blowing and drifting snow will be an issue with this system. We'll see if models continue this trend, but just a heads up that we could be dealing with another fairly intense system Friday into Saturday morning.

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  37. Rob, how did Winnipeg rank in terms of coldest December's??

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  38. CTV news claims Winnipeg had the coldest December in over 100 years. Is this correct? If not, where does this Dec temperature rank?

    Thanks for all you do.

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  39. Anonymous..

    No, that's not quite correct. December 2013 ended up with an average temperature of -20.8C, which is the coldest December since Dec 2000 with an average monthly temperature of -22.0C. However, the next coldest December was back in 1893 with an average of -21.4C, so Dec 2013 was the SECOND coldest December in over a century (after Dec 2000).

    Dec 2013 ended up as Winnipeg's 6th coldest December since 1872.

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  40. Here are the top coldest Decembers in Winnipeg since 1872..

    1. 1879 .... -26.0
    2. 1872 .... -22.6
    3. 2000 .... -22.0
    4. 1876 .... -21.8
    5. 1893 .... -21.4
    6. 2013 .... -20.8

    The average December temperature is -13.5C (1981-2010 average) so Dec 2013 was over 7C below normal.

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  41. NAM has come down quite a bit on the 18Z run.. now showing about 7-10 cm for Winnipeg rather than 20 cm. That's more in line with what the other models are saying right now, so we'll see if they stay consistent on those amounts in the next day or so. For now, models are giving a general 5-10 cm for Winnipeg with Friday's system.

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  42. NWS Grand Forks has issued a special weather statement for snow and blowing snow and life threating windchills from -40 -60 below zero for their area.

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