Wednesday, March 21, 2012

Staying mild through Friday.. turning cooler this weekend with some rain possible

The well above normal temperatures will continue for a couple more days this week, before we get a cool down this weekend along with a chance of some showers. Temperatures are expected to climb towards the 20C mark again by Thursday, which if reached, would be the third 20C day recorded this month, matching the total number of 20C March days in the past 140 years. Increasing clouds Friday will give way to a chance of showers Saturday as a cold front pushes through, with cooler conditions in the single digits for Sunday. In fact, temperatures will only be dropping to normal values for this time of year.. but then, you'll have to forgive people if they've forgotten what normal is over the past couple of weeks. Temperatures are expected to be back above normal values for the last week of March, which will likely head into the record books as the warmest March on record in Winnipeg since records began in 1872.

UPDATE: Thu March 22: A record high of 21.7C was recorded today at Winnipeg airport, breaking the day's previous record high of 18.3C from 1878. It was the city's 8th record high in the past 12 days, and the third day this month of at least 20C.. equalling the total number of 20C days recorded in Winnipeg in March in the past 140 years. Note also that all 20C days this month occurred earlier than any previous 20C readings.

20C days in March - Winnipeg (since 1872)

1. 23.7C ..... Mar 19 2012
2. 23.3C ..... Mar 27 1946
3. 22.8C ..... Mar 23 1910
4. 21.7C ..... Mar 22 2012
5. 20.9C ..... Mar 18 2012
6. 20.6C ..... Mar 28 1938
* 19.9C ..... Mar 16 2012

* Note: Winnipeg had a high of 19.9C on Mar 16th this month, narrowly missing another official 20C day by 0.1C. For all intents and purposes however, one could consider that another 20C day, in which case it can be argued that Winnipeg had more 20C days this month than in the past 140 Marches combined. (note that before Canada went metric, temperatures were measured in deg F, which were converted to metric equivalents in 1975. A temperature of 19.9C before 1975 would have been recorded as 68F, which would have been converted to 20.0C when we went metric)

32 comments:

  1. Complex forecast for the next week. Baroclinic zone just south of the intl border, will sharpen up and waffle north and south thru the weekend. Front pushes north tonite with weak LLJ of 30 kts, but deeper moisture will still be off to our south. There may be a few mid-level clouds (especially thru the interlake) before they lift out.

    Eventually, moisture and clouds coming up from a cut-off low over the central plains will have a tendency to back in from the southeast. At the same time, a disturbance in the SW flow will try to push drier air (especially above 850 hPa) east and shove the moisture and clouds into Ontario and Minnesota.

    Given the tug of war between the two systems, cloud trends (especially low clouds at 925 hPa and below) will be hard to pin-point for Friday. The exact frontal position and timing of its passage also adds uncertainty, as area of sharp temperature gradient starts slumping south late in the day. Cold advection at the surface continues thru the day Saturday, but by overnite into Sunday morning, warm advection aloft and weak LLJ may give us a shot at some elevated showers.

    Blocking pattern then begins breaking down as cut-off low is forecast to slide east. That allows upper ridge to build over the western plains and re-inforces cool surface high pressure down into S Manitoba. High pressure quickly shifts east and sets the stage for moisture return - ahead of what could be a potent low pressure system tracking NE up thru N Dakota and Minnesota. We may be affected by the deformation zone and/or trowal wrapping around the system. Enough cold air looks to work in for a change over to slushy snow on the backside..

    Daniel

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  2. Great summary Daniel. I agree that cloud cover is going to be very difficult to pinpoint on Friday; which could also dramatically impacted by both the LL moisture as well as the front passage timing.

    I'm keeping my eye on the system next week; looks like it could potentially be a significant one...

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  3. Petawawa, Ontario recorded a temperature of 28.8C this afternoon! That is the highest temperature this year in Canada.

    Meanwhile, Montreal (25.8C), Ottawa (27.4C), Windsor (27.8C), Hamilton (25.6C) and Sarnia (27.9C) were among the several places that broke all-time March highs today.

    Biggest and most intense heat wave I have ever seen. Very close to the Moscow one.

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  4. Should be another record breaker today. Chalk up another 20 C reading this month ?????

    Could be 3 times in one month, while before it took 140 years! Stunning!

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  5. Some interesting facts about the current March heat wave from Jeff Masters from Weather Underground. All time March highs recorded across numerous cities in eastern Canada, with several Maritime sites exceeding not only their all time March highs, but April as well! In fact, Halifax is forecast to hit 28C today which is warmer than any April temperature on record (26.3C). Incredible. Click on my name for link.

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  6. I just read Jeff Master's blog. Just when you thought things could not get any crazier....

    Winnipeg airport is at 16 C right now at noon time. Another 20 C seems certain, as there is not a cloud in the sky to filter out any solar!!

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  7. New Brunswick is witnessing diurnal ranges that are more typical of the Prairies.

    Highs in the mid to upper 20s and lows in the 0 to +3 range for many places in inland NB yesterday and today.

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  8. Flawless day. Full solar, light winds, no bugs,......

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  9. Flawless is right. Even though we won't be as warm as our record breaking Monday, it feels a lot nicer today with the lack of wind, the brighter sun, and the lower humidity. Stellar day out there.

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  10. Check out Environment Canada's special weather statement on all the records that were broken today!!

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  11. All the patios down Corydon AVE. were OVERFLOWING with people this evening. You would think it was a night out in June :)

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  12. Rob, what is your opinion for Saturday's outlook? E.C. says sunny and 18C but NWS forecast for Pembina says 50F and windy. Based on past experience I'm thinking NWS is more accurate. Thoughts?

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  13. Mark.. Saturday looks like we'll start off mild, then a sharp cold front will pass through in the morning, and our temperatures will drop dramatically during the day reaching single digits by afternoon. Take a look at the 48hr graph of RGEM temperatures for Winnipeg (under the forecast icon) RGEM has Winnipeg at 15C at 9 am Saturday falling to 6C by noon as those NW winds kick in, then +1C by 6 pm. Based on current model trends, I would say that sunny and 18C is not likely for Winnipeg Saturday.

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  14. Western Head, Nova Scotia was 29.2C today which is quite possibly the warmest temperature ever recorded during the month of March in Canadian history.

    The warmest temperature for Canada I could find was Medicine Hat, Alberta at 28.9C(84F) on March 23, 1911.

    btw-Windsor broke their all-time March high for the third straight day.

    Absolutely insane!!!

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  15. Never mind... the 29.2C in Western Head is probably the second warmest temperature ever record in March in Canada

    The sizzling maximum temperature of 28.8 c reported in Petawawa
    Wednesday is the second highest temperature ever recorded in
    Ontario in March. The highest temperature recorded during March was
    A midsummer like 29.4 c in Wallaceburg on 26-mar-1921.

    http://weatheroffice.gc.ca/warnings/SWS_bulletins_e.html?prov=on

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  16. Quite the rise in humidity overnight as Winnipeg got into a light southerly flow which advected in those higher dew points again. Meanwhile, it's only 4C in Portage with a 0C dew point and NW wind. Temperatures in Winnipeg today will be tricky depending on if we can clear out of all this low cloud, and if that frontal boundary to our northwest slips back.

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  17. Is the overnight lo a record?

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  18. How unusual is it to see fog on the (no ice) Red River in March?

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  19. Maybe I'm just getting spoiled but I want another 20 C reading today....LOL!

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  20. Record high minimum for today is +6.7C in 1945. Airport has been above 10C since midnight,so we will break that record easily. It will be our 9th record high "low" this month, on top of the 8 record highs we've hit. It will take a long while before we take down 2012 for March warmth..

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  21. My spidey sense is telling me we won't reach 20C today.. too much low cloud, too humid, and not enough wind to flush things out. Aircraft AMDAR data out of Winnipeg this morning show saturated low levels up to 7000 ft, which is a pretty thick layer of moisture to burn off. You'll just have to put up with a measly 17C instead!

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  22. Latest soil temps for the RRV show only a small below-freezing layer from 50cm - 100cm. It's sitting at around -0.7°C and warming by the day. Soil temps above and below are as high as 4-5°C. If we get more snow, we'll have a hard time keeping it as the ground is abnormally warm for this time of year!

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  23. Jeff Master's blog is another must read today.

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  24. Winds in Winnipeg have shifted to NW.. temperature at the airport has dropped 2C in the past 10 minutes to 14C now. No 20C today!

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  25. In the strange but true phenomena..while we have been basking in the summer like weather the Arctic Sea ice extent 15% or greater has expanded to levels not seen in the last nine years
    My name or
    http://wattsupwiththat.com/reference-pages/sea-ice-page/

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  26. Thanks Brad..

    In spite of the low level clouds, that deeper moisture and rain associated with trowal of the central plains low (showed up nicely on the 700 hPa dewpoints and theta-e), never did quite make it into Manitoba.

    With front coming thru by mid-morning to midday.. question then becomes how cold it will get Saturday nad Sunday nites. Arctic high starts nosing in early Sunday morning, but a bit of cold advection and a gradient at 925 may keep some mixing going. The other wild card appears to be mid and high level clouds, that will stream east over-top the ridge. The lower, thicker clouds will be down in N Dakota however. With 850 hPa temps at -5 to -7 C, will have to see how cold the calm, clear areas (off to our NW most likely) can get - with a lot of ground heat and moisture flux likely.

    High lingers on Sunday nite as well, but by dawn mid-level clouds start moving up from the SW. Temperatures will tank early and then stabilize, depending on the timing of the clouds.

    LLJ gets cranking overnite Monday, with showers moving up from the south. Cold air starts wrapping in by Tuesday afternoon heralding a possible change over to slushy snow :(

    Daniel

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  27. Re D'Thomas..

    Above average, arctic sea ice this year wouldn't be inconsistent with a strongly positive AO. A strong polar vortex and jetstream keep the arctic air bottled up over the higher latitudes, possibly causing more sea ice to form.

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  28. I was wondering if the Artic sea ice would rebound this winter since the cold was bottled in up north. I know I had asked that earlier in the year nice to see that it did make a difference now I wonder what the cause effect will be now?

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  29. Freezing rain warning expanded to include SW MB all the way to US border. Band of showers and even some thunderstorms over SE Sk will move into southern MB tonight, with subfreezing temps over SW MB causing freezing rain. Will come in as rain for Winnipeg/RRV overnight along with the chance of a thunderstorm. Much cooler for Saturday with falling temps, and our first freeze in almost 10 days by Saturday evening.

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  30. Just a note: Someone here mentioned the highest temperature ever in Canada in March. Jeff Masters also referenced that in his latest post.

    He notes that Chris Burt notes my hometown of Port Alberni, BC (Beaver Creek station) has that record, at 31.1C on March 29, 1926.

    However, I looked at the EC data from that time and I think the Beaver Creek staiton was overestimating the temperature by quite a bit.

    On March 29, 1926:
    Beaver Creek measured 31.1C
    City of Port Alberni measured 23.1C

    The stations would have been only a few miles apart, Beaver Creek deeper in the Valley and Port Alberni in the City proper next to the Inlet.

    I don't generally see temperature differences of more than 2 or 3 degrees in the height of summer between my station (in the City) and the current official station at the Airport (in the Valley closer to where the Beaver Creek station would have been).

    So I find it hard to believe that the difference would have been almost 8 degrees.

    There is a chance, as it may have been foggy in town for longer, where as Beaver Creek may not have been foggy at all. But again, I'd be surprised.

    I looked at Lake Cowichan which is in the Cowichan Valley further south on the Island that usually gets similar temperatures, and it was only 21C. Similarly, Chilliwack, in the Fraser Valley on the mainland only go to 20C on that day.

    All this to say... we're witnessing an incredible event!

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  32. New Brunswick is witnessing diurnal ranges that are more typical of the Prairies. Highs in the mid to upper 20s and lows in the 0 to +3 range for many places in inland NB yesterday and today.

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