Friday, September 18, 2009

Last official weekend of summer to be summer-like!

It looks like Mother Nature is trying to make up for her abysmal performance this summer with a glorious stretch of sunny warm weather heading into the last official weekend of summer.  Temperatures have been above 25C all week long with sunshine, and the warm weather will continue through the weekend before a cold front moves through late Sunday.  Saturday will see temperatures rise to the 30 degree mark over much of southern MB, especially over western MB where temperatures of 32C are forecast.  Sunday will continue to be warm, with gusty southerly winds pushing temperature into the mid 20s before clouds approach in the afternoon and evening ahead of the advancing cold front. This front will usher in occasional showers Sunday night into Monday with a return to more seasonable temperatures in the upper teens. However, long range models are now indicating that the cooler weather will be short lived as above normal temperatures are forecast to return by mid to late week. This virtually ensures that September 2009 will likely go down as the warmest September on record in Winnipeg since records began in 1872.  After 9 consecutive months of below normal temperatures, it’s the least we deserve!


  1. Rob!
    Did any records fall in southern Manitoba today???

  2. Hi from down south...

    Just wanted to pass on some updated winter outlook info from our local climate expert at our office. Below are some of his thoughts...with the caveat of course that it is early and of course things change.

    Yesterday, Tuesday the 15th of September, I sat in on the CPC internal winter outlook teleconference. At the present time, there is a great deal of doubt as to the impact of this years El Nino, due in part
    to the nature of this event and the presence of a negative PDO. Several of the statistical and deterministic models flat line the current event, that is maintain it as a borderline ENSO neutral/weak El Nino. The bulk of the models make it a solidly weak El Nino, with fewer members making it reach the moderate or strong category.

    Basic Premise: The main theme for this winter is one of a non-standard El Niño. The negative PDO will exert one type of long term pattern influence, and the El Niño the opposite. This process, known as destructive interference will cause extreme variability in the 'weather'. MJO influences will be amplified by this atmospherically antagonistic attitude. This destructive interference of the El Niño signal will lead to more normal temperatures this winter than in the typical El Niño event. Snowfall will quite probably be enhanced as well since the frequency of southwest flow or wet northwest flow events will be greater.

  3. Thanks for that Dan. Hard to think about winter with the great September weather we're having! The CPC call falls in line with what I was thinking for the winter outlook.. more variable with greater temperature swings as we battle Arctic cold with El-Nino moderated Pacific airmasses that will try to pass through. I'm hoping there will be enough moderation from the occasional Pacific influxes to make the winter more bearable. The downside with a more variable/volatile pattern is that it often comes with more wind and snow.. which can make the winter less pleasant. Here's hoping for a milder winter!

  4. A couple of minor records set yesterday.. I expect a few more today, although Winnipeg (31.2C), Brandon (31.7C) and Dauphin (33.3C) will likely fall short of their records for today.

    Should be more numerous records in southern SK today with temperatures rising into the mid 30s over the southwest!

  5. Rob!

    Here is another question for you!

    Is it possible for there to be a
    "dryline" setup here in Southern Manitoba.

    You know the dryine you here about causing massive thunderstorm development in Oklahoma and Texas.

    The reason I ask because I noticed that the depoint spread between Brandon and say.... Winnipeg has been by a 2- 5 C almost every day this week!!!

  6. As of 3:00 pm Portage La Prairie is already 31 C !

    Looks like some records will fall!!

    29 C in Winnipeg.... almost there!!!!

  7. Another thing to watch out for during influxes of balmy Pacific air during winter (in this part of the world) is the often treacherous combination of freezing drizzle and fog.

    'Drylines' do not occur as such in Manitoba.. they are simply refered to as troughs or pre-frontal troughs. That is because the eastern prairies and upper midwest are too far removed from the downslope regions of the high plains. The best drying is associated with compressional heating and excellent mixing on the lee side of the Rockies. By the time the dryline has reached the RRV, the air behind the trough has modified greatly from due to moisture from lakes and evapotranpiration. Therefore the dewpoint differences are never as dramatic as further west. Only in drought years where topsoil moisture levels are depleted is there a potential for drylines to occur here.

  8. Our first official 30C day of the month in Winnipeg.. we had to have at least one in what should be the warmest September on record!

    A half dozen records so far in MB.. official list will come later today. Manitoba hot spot so far is Carberry at 32.4C.

    Core of the heat is in SK where at least 22 new records were set today.. including Moose Jaw at 35C, Regina at 34C and Saskatoon at 33C. Speaking of dry lines, drier air has pushed into southern SK with Moose Jaw at 35C and a dewpoint of +2C, giving a relative humidity of 13%. Now that's dry!

  9. Thanks Rob...

    With all the cheering for the warmth...I almost feel like I have to present the other side of the story. I dreamed growing up in the state of Kentucky of moving to the North Battleford SK or Saskatoon as most of the time the path of the arctic highs drop down that way and it can get quite cold in the river valley. I got as close as I could work-wise in the states. But seriously I cannot wait for this heat to end and the winter to come as I just hate going outside in this heat.

    Enjoy the warmth....but dont spoil the enjoyment of the cold for me!

  10. Dan.. you need a posting at the Fairbanks office! :)

    Another 25C day expected today, which would make 16 for the month.. tying the Sept 1940 record. Models now show we may squeeze out another 1 or 2 days of 25C this week, which would set a new record for most 25C days in September. Only fitting given that this will most likely be the warmest September on record.

    The turnaround from this past summer is extraordinary. September will likely finish with a monthly average greater than July's 16.5C. That has never happened in Winnipeg's climate history since records began in 1872.

    Let's hope the trend continues in October! (sorry Dan!..)

  11. No problem Rob good you can enjoy the warmth! I want to pass on that I enjoy your blog a lot and check out your website frequently and pass on any info that I find pertinent onto our staff at NWS Grand Forks. Keep up the good work everyone and I enjoy seeing all the posts from our great friends in Manitoba.