Saturday, September 10, 2011

Record heat possible today.. fall like weather arriving early next week..

The long hot dry summer of 2011 continues today over southern Manitoba with another 30C+ day on tap.. our 4th in a row in Winnipeg, and the 23rd occurrence of 30C or more temperatures this year. Several record highs are likely again today over southern Manitoba, including Winnipeg where 1998's mark of 32.4C set on this date in 1998 is in jeopardy. Another summerlike day is expected Sunday with temperatures in the upper 20s, not quite as hot as today as we get into a light northeast flow of somewhat cooler air.

Big changes are on the way though as we get into Monday and Tuesday. A cold front will push through southern Manitoba Monday with clouds and a chance of showers, with gusty northwest winds developing bringing in cooler air. By Tuesday and Wednesday, high temperatures will only be in the low teens along with clouds and brisk northwest winds along with some lake effect showers off the Manitoba lakes. High pressure will build in by Wednesday and Thursday which will likely produce the season's first widespread frost to southern Manitoba. Moderating temperatures are expected by the end of the week into next weekend as temperatures return to more normal values for this time of year (around 20c). So enjoy the warm weekend.. this could be summer's last hurrah!

32 comments:

  1. I looked ahead on the EC seasonal outlook towards the Fall and Winter looks like we could have above normal temps through fall along with below normal precipitation, although the percentage of correct outlooks is quite low. For our Winter, the first half looks quite cold (below normal temps) along with below normal Precipitation, meaning less snow. Things start looking up during our second half of winter warmer weather, and more precipitation. This means there is a higher likelihood of flooding, and chances for big snowstorms.

    The spring will have near normal temperatures, with higher precipitation meaning more storms. As summer approaches we could see warmer than normal weather and wetter than normal conditions.

    It is still to far ahead to accuratly predict, but EC was right all of last year for our warm dry summer we had. Lets hope that the weather cools gradually over the next week and not have a sharp dip in temperatures.

    Is our storm season done for the year yet? when does it start and end?

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  2. Is 4 days of 30C in September a first for Winnipeg?

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  3. Anon....


    No I don't think so, we have had other days in the past where we surpassed 30C in September such as september of 2009 for example. We have broke a few records this week, just not a multiple number of days in a row.

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  4. Anon, interesting question. After checking through all the Septembers since 1872, the most 30C days we've had in September was 5 days, in 1897, 1906, and 1940.

    1908, '15, '23, '38, '48, '52, '78 all had 4 days of 30C in September.

    So it seems our streak of 30C this September is, yes, quite rare. Hope this answers your question.

    Side note, we hit 38,8C on Sept 2, 1983. =)

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  5. re: 30C days in September for Winnipeg. There have been several Septembers with four days of 30C or above. The most I can find is 5 days, recorded in Sept 1940 and Sept 1897.

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  6. Thanks for the stats JJ.. you beat me to it :)

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  7. I'm surprised because all of the other big canadian cities seem to get a longer stretch of hot weather, and some of them are to our north. Example of that was the summer of 2009 when Provinces such as BC and NWT were basking under never ending heat, while we were taking the cooler wetter weather by being on the other side of the ridge. This year has been exceptional for the heat.

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  8. Thank you for the info!

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  9. your welcome, anytime! You can ask me and the other guys anything.

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  10. A high of 31.4C at YWG today.. not quite enough to beat the record for today.

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  11. No records broken here, but what a way to end the summer season. Now prepare for the cold blast (cold compared to what we just had)...

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  12. Thanks JJ and Rob. I thought the record would be more than 5 days at 30C+.

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  13. Nice smell of smoke in the air this morning.. likely from a forest fire that was burning just west of Flin Flon last night.

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  14. That smoke is getting noticeably thicker this afternoon in Winnipeg.. very strong smell and visibility is lowering. Observer at YWG airport still calling it haze.. but he should be calling it smoke.

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  15. With some luck Winnipeg may escape frost this next week. Greatest threats would come on Wednesday and Thursday mornings.

    However for Wednesday, with strong moisture flux off the lakes.. models suggest lingering stratus and decent winds at 925 hPa preventing a spike down in temperatures. Ridge axis moves overhead during the day Wednesday, but with the high pressure centre progged to drop well south, there is atleast some chance of trapped low level moisture/stratus hanging on as return flow sets up by dawn Thursday.

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  16. Rookies at the airport.... Rob, go over there and show them who's boss!!!
    LOL!!!

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  17. Rain for the interlakes tomorrow morning, nothing here. Could get quite cold this week, lets hope we don't break any low temperature records. Well Time for fall, and goodbye to summer.

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  18. I am golfing near Victoria Beach tomorrow and wondered if I'll need a "slicker" That is Lake Winnipeg Fishermen gear isn't it?
    What is the windchill for +8C winds 40 gusting to 60 in the rain in thunderstorms...

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  19. Windchill will be the least of your worries.

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  20. I agree, the slicker might act like a parachute and make one airborne at inappropriate times. The long graphite and steel shafts should provide some stability as well and keep one grounded. A gross of Golf balls might be enough to survive the wind.
    Are these forcasts tomorrow exaggerated ??

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  21. Still uncertainty regarding low temps Wednesday morning. Models continue showing main ridge axis and calm winds up (all the way up thru 850 hPa) over Saskatchewan and far western Manitoba where I would expect the coldest temps. For us, there will be a 30 kt flow at 925 hPa off the lakes the entire night. RH fields from the models also hint at possible lake effect clouds lingering into the night. By Wednesday overnite we develop a westerly and then southwesterly return flow, which may keep temperatures above zero (assuming we do not spike down early in the evening).

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  22. Rob!
    Tomorrow's cold front looks to pack some serious punch!! Temperature falling to 8....yikes!!

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  23. EC mentionied that there will possibly be vigourous lake effect showers and tstms occuring off lake manitoba, with the passage of tomorrows cold front. I wonder why they say vigourus? do they mean thers a chance for severe storms. At this time of year, really?
    Well if you want the good stuff head to Sault Ste. Marie, as there are numerous storms making an approach into their area as of 9:22 pm CDT. Scattered lightning althroughout the centre of the storms. Well i guess were out of luck with the temperatures expected to drop to 8C here tomorrow, no way well see storms after that. Fall is on the way!

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  24. Seeing severe t-storms is only a fantasy here in southern MB, especially this year!

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  25. Fall is definitely coming but if you believe the ECMWF models, they're calling for unseasonably warm right through to the first week of October.

    One extra week of warm weather means one less week of winter (I hope).

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  26. I hope this winter is not as bad as last year, I hate it when its cold. I'd really love for an El Nino to form sometime before winter, that means warmer weather less snow, and warmer wetter conditions in summer.

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  27. 8 degrees at YWG and 16 degrees at Victoria Beach. Lake Winnipeg sure is warm! I think places along the south shores of the lake should be frost free well into October.

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  28. With the cold air aloft and some warm lake temperatures we could see an emergence of lake enhancement storms/rain this afternoon. If storms occur expect them to be non severe in Nature, Our chance of seeing something is 50/50.

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  29. That warmth on Lake Winnipeg has extended southeast to Garson and Beausejour this morning where at Garson it has warmed from 7C at 8am to 14C now. Perhaps due to a 46k WNW wind at Victoria Beach where it remained at 14C overnight.

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  30. Mike..

    The mention of "vigorous" convection in PASPC's discussion is relating to the intensity of lake effect, not in terms of severe thunderstorms. Intense lake effect will give you heavy rain (or snow) with possible lightning strikes in more extreme cases, but even the most intense lake effect convection has tops of only 15-20,000 feet compared to 50-60K feet with severe summer thunderstorms. So intense lake effect will not give you severe winds or hail, but can give locally heavy bands of precipitation and poor visibility.

    So how do you get intense lake effect? You need 3 things.. 1) strong instability over the lakes with cold air over warm water.. ideally 20C or more temperature differential between lake temperature and 850 mb temps. 2) Well aligned winds in the lowest 10k feet along the lake axis. The less directional shear you have below 700 mb, the more likely you will set up one or two strong lake effect bands off the lakes. 3) lack of subsidence inversion. If you have an inversion in the lower levels, it will weaken or prevent lake effect from occurring, particularly with subsidence (sinking air) moving in.

    In our upcoming event later today into tonight, we have most of the above conditions coming in, so we should be seeing some fairly intense lake effect developing off all 4 MB lakes, the most intense off the north basin of Lake Winnipeg. 850 temps of -3 to -5C over 17-19C lake water will give 850-lake temp differentials over 20C which is extreme instability for lake effect (minimum threshold is about 13C). Winds become well aligned around 330-340 degrees down the lake axes for maximum fetch, so look for some intense lake effect bands to develop off southern Lake Winnipeg through the Beausejour area.. and off Lake Manitoba between Portage La Prairie and Elie. Heavier bands of lake effect likely off the north basin of Lake Winnipeg north of Arborg. Pcpn should be mainly rain due to the warm lake waters, but there is a potential for some snow to mix in off the north basin streamers due to intense convection which can lower freezing levels due to evaporative cooling from latent heat release. (basically, the low levels keep cooling from falling snow, which lowers the snow level until eventually it surfaces)

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  31. Winds are starting to pick up out of the NW here in Winnipeg! Cold front has passed here I assume!!

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  32. Nice post Rob!!!
    That would have taken me about an hour to type that out.....(now where is the "H" key????)

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