Monday, September 03, 2012

Cooling off this week as kids head back to school

The traditional last weekend of summer ended up on a sunny and warm note over Winnipeg with temperatures rising to 29C for Labour Day Monday .. some 8C above normal for early September. But the summerlike temperatures will be on their way out this week as a large storm system over the northern Prairies pushes cooler air towards southern Manitoba over the next few days. Tuesday will see a mix of sun and cloud with highs of 24C, about 5C cooler than today but still seasonably warm for early September. Tuesday night, a cold front will track across southern Manitoba bringing a chance of showers, along with a push of cooler air for Wednesday and the rest of the week. Temperatures will be noticeably cooler as the kids head back to school, with autumn like highs in the upper teens to near 20C through Friday. Sunny and warmer conditions are forecast for the upcoming weekend.      

23 comments:

  1. Rob,
    question....

    I've heard of a possible big cooldown next week.

    Could we be in for the season's first frosts?

    ReplyDelete
  2. Gimli Harbour is acting up again. It just spiked from 26 to 31C, and the media is reporting it as the hotspot.

    ReplyDelete
  3. @anonymous.. It looks like a nice warmup over the weekend into early next week before we cool off again by mid to late week. Not sure how cool it will be but I see Euro is hinting at some below normal temps by the middle of next week. Ensembles don't really show anything abnormally cool however.. so, still lots of uncertainty about how cool it will get. For comparison, last year, which also featured a warm and dry summer, our first frost of the season came on the night of Sept 13-14th, about a week earlier than normal. Normally we see our first frost in Winnipeg around Sept 21st.

    ReplyDelete
  4. Gimli Harbour checked in with a max temp today of 35.9C, while Gimli station just inland was 26.8C.. so yeah, definitely something screwy with that Gimli Harbour sensor.

    ReplyDelete
  5. CBC reported Gimli again this morning as the hot spot yesterday, at 36C. Time for a real-time quality control program, like MADIS uses.

    Today's YWG forecast is anywhere from 21C (CBC) to 26C (NAM & RAP).

    ReplyDelete
  6. Agreed.. A better QC program is needed for our monitoring network to ensure that erroneous data is not being disseminated, or even worse, archived. Some suspect data may be too subtle for a QC program to catch, but there are obvious ones that should never go out (like the "heavy snow" report from the New Orleans AWOS during Isaac. How difficult is it to program a QC check that if it's 27c in August and there's precip falling, it can't be snow!)

    ReplyDelete
  7. >>> Today's YWG forecast is anywhere from 21C (CBC) to 26C (NAM & RAP).

    Once again, reality will likely lie somewhere in between those forecasts. We have a lot of cloud streaming in over southern MB with some thinning towards the intl border. If we stay cloudy all day, then 21c is reasonable.. With sunshine, 26c is possible. Given some breaks of sun, I would say 24c is a good bet for Winnipeg today, with 26c more likely to our south and east..

    ReplyDelete
  8. 21C already, under cloud. That was fast.

    ReplyDelete
  9. Looks like 26 wasn't much of a stretch after all. 27 may even be within our reach.

    ReplyDelete
  10. Yeah, that sunshine really helped us.. Cooler air on the way though with 20c temps near the SK border..

    ReplyDelete
  11. 27C!

    "Once again, reality will likely lie somewhere in between those forecasts."

    I would normally agree, but once again, the exception to the rule won out. LOL


    ReplyDelete
  12. Wow. 30C in Morris! Oh wait, another source shows 27C. How many stations can there be in Morris?

    ReplyDelete
  13. Nice northern lights this evening in Winnipeg around 9:30 pm.. anyone else see them?

    ReplyDelete
  14. I don't think we have a weather station in Morris... the 30C is from the Emerson station, which is the closest one to Morris.

    ReplyDelete
  15. I see a Morris station on the MB Ag weather site. They were 27C while a media source showed 30C on their map for Morris. They also had bad info for Winnipeg so must be having technical issues.

    ReplyDelete
  16. Interesting that the public forecast is bumped up several degrees from the raw SCRIBE, and warmer than any model. A result of yesterday's unexpected heat?

    ReplyDelete
  17. Well, we blew past 19C, still climbing. MSC takes the prize yet again.

    ReplyDelete
  18. Yeah, Scribe temperature guidance has been consistently 2-3c cooler than actual highs for Winnipeg lately, sometimes even as much as 5C. Supposedly there was some recent tweaking with low level stability in the RGEM that may have affected UMOS temperature guidance, but I don't know for sure if that's the reason. Whatever it is, there has been a noticeable cool bias with the RGEM SCRIBE guidance lately and forecasters have been adjusting temperatures accordingly.

    ReplyDelete
  19. Here's the best example yet of when NOT to use ensemble forecasting.

    TS Leslie is supposed to hit St. John's next week Wednesday/Thursday. But the public forecast simply says "Mix of sun and cloud". Why? Because those days in the public forecast are based on the Ensemble mean. Some Ensemble members do actually actually see the TS, but the mean of course does not.

    And the forecasters aren't allowed to adjust the extended range so are sitting there just about exploding inside, being forced to hit the 'submit' button on a forecast they all know is very likely wrong, and even potentially dangerous to public safety.

    End of rant....

    ReplyDelete
  20. OK, perhaps saying it will hit on a certain day isn't the best idea at this point, and resident there likely know of the risk already despite the public forecast. But at least hint that it's arriving - let the forecasters use their brains and training.

    At least SCRIBE will be used in coming days, and the forecast will likely change.

    ReplyDelete
  21. Garth.. That's one of the reasons why I started my blog.. to give more insight into those simplistic automated forecasts that don't really tell the whole story. Although hurricanes aren't an issue for us, winter storms are.. and I think it's worthwhile information to know that a potential storm may strike your area in a few days time, while the official forecast only calls for a mix of sun and cloud.

    At least the maritimes have the benefit of forecasts from the Canadian Hurricane Center who can follow these trropical systems well in advance, and give people considerable more information than what they get from the general public forecast.

    ReplyDelete
  22. Absolutely Rob. Same applies to significant thunderstorm events in the summer. Some of the major summer events can be predicted (or hinted at) a week or two out, yet EC forecasts past day two do not mention thunderstorms.

    ReplyDelete
  23. Not a good day to be on the water for recreational boaters today. Winds gusting over 40 knots this morning on Lake Winnipeg with nearly 3 meter waves being reported off Hecla. Gale warnings in effect.

    ReplyDelete