Sunday, August 26, 2012

After a cooler weekend, another shot of 30C heat coming this week.. along with more dry weather

The summer of 2012 is hanging on in southern Manitoba as August draws to a close. After 3 days in the 30s in Winnipeg last week,  the weather turned breezy and a little cooler over the weekend, albeit with temperatures still quite pleasant near the 25C mark.. which is still slightly above normal for the end of August.(normal high of 23c now)  More fine weather is in store this week as high pressure drifts over southern Manitoba, bringing clearing skies and light winds on Monday with highs near 26C. The heat will be moving in again by midweek as an upper ridge of high pressure builds over the eastern Prairies once again, with southerly winds pushing temperatures over the 30C mark by Wednesday. In fact, there's a potential for 35C temperatures Wednesday over the Red River valley as a very hot airmass pushes into the central continent. (Temperatures of 35-40C are possible over North Dakota Wednesday)  Slightly cooler temperatures are expected by the end of the week, but still staying near or slightly above normal.

Those looking for rainfall will be disappointed by the weather this week, with no real prospects of significant rain in the near future. Things have turned quite dry over southern Manitoba over the past couple of weeks, after a somewhat unsettled first half of the month that saw some significant rainfall at times. Even so, Winnipeg has seen only 43 mm of rain this month, just over half the average August rainfall of 75 mm. This will be the third month in a row with below normal  precipitation in Winnipeg, with 130 mm of rain recorded since June 1st, just over half the summer average of 235 mm. This comes on the heels of last year's dry summer, which ranked as the 5th driest summer on record in Winnipeg with only 93 mm of rain for the 3 month period of June, July and August.      

73 comments:

  1. Note that Winnipeg airport recorded 4 mm of rain on August 3rd, which is missing from the monthly climate summary. Thus YWG rainfall total this month is 43 mm, not 39 mm.

    ReplyDelete
  2. New GLB run tonight has Winnipeg with a high of "only" 31C Wednesday, with 34C from the NAM. Both models indicating 850 temps up to 26C Wednesday over the RRV.. and 30C over SW ND. I would think 35C would be widespread with 850 temps that high. NAM going nuts with the heat over North Dakota Wednesday with a high of 42C (107F) forecast for Grand Forks!

    ReplyDelete
  3. Note that Winnipeg's forecast high of 31C Wednesday seems a little low given that highs of 35C are forecast everywhere else in the RRV Wednesday, including Portage, Steinbach and even Selkirk. Odd that Winnipeg is 4C cooler than everyone else. Given the setup, I'm thinking 35C is a better estimate.

    ReplyDelete
  4. NAM now has 38.1 C for Wednesday!!! (That's not even the MAX temp from their grib data, just the temp on the hour). Seems a wee bit extreme. It also has the dew point dipping below 5C while the GEM-GLB has it way up in the high teens. Quite the difference.

    ReplyDelete
  5. Im a little confused. Some models have the significant remnants of TDIssac barrelling up I29and35north of Mpls on wednesday and we are expecting a dewpoint of 5C?

    ReplyDelete
  6. oops Confused &errorprqne. sb Thursday

    ReplyDelete
    Replies
    1. Problem solved. Even WUs Wundermap will correct on next update when it makes no sense. Dry it is

      Delete
  7. EC, The Weather Network, Weather.com, Weather Underground, CTV, even Accuweather all have at least 30C for Wednesday. But our CBC Winnipeg forecast is only 26C. Strange.

    ReplyDelete
  8. With the models not agreeing on a daytime high, I think it should go to the polls.....

    ReplyDelete
  9. CBC changed their forecast to 33C on Wednesday.

    But now he is also forecasting 30C for today, with 'breezy' winds?!!

    "Weather Journal for August 27th
    Current Conditions

    Sunny, Hot and Breezy today. We should reach 30 degrees later this afternoon."

    ReplyDelete
  10. At least only 1 source screwed up today's forecast. Wednesday continues to be a challenge with the 18Z NAM still calling for 37 C.



    ReplyDelete
  11. Updated forecast now calling for 33C Wednesday for Winnipeg.. which is a step in the right direction. Models consistent at showing 850 mb temps rising to 26C over us Wednesday afternoon with sunny skies, moderately low dewpoints, and a strong southerly flow. That would support 35-37C for us. NAM going with 37-38C with dewpoints dropping to 10C or lower in the afternoon to maximize heating. Last Aug 23rd when we hit 37C, our 850 mb temp was 24C, but we also had a southwest surface wind to help boost our temperature up with some help from downslope. On Wednesday, we don't have a downslope component with a strong southerly wind up the valley, but 850 mb temps are a little warmer at 26C. So put it all together, and I think 35C is likely Wednesday, with 37C possible if dewpoints are low enough. Either way, it'll be a hot one.. possibly the hottest day of the year (currently 35.4C on July 29th)

    Tomorrow we may hit 30C as well as 850 temps climb to 19C by the end of the day with light southeast winds. 30C temps forecast Tuesday south and west of Winnipeg.

    ReplyDelete
  12. >> Anonymous said...

    With the models not agreeing on a daytime high, I think it should go to the polls.....

    Good idea! It's been awhile since I had one.. poll coming up!

    ReplyDelete
  13. Old record Wednesday is 36.1°C in 1972, so it isn't even a clear shot at breaking a record. Could go either way.

    ReplyDelete
  14. Appears Hudson Bay (water temp) east coast and to a lesser extent the west side are pushing +4 to +5C anomoly. Is that 13 to 15 C?
    Rob do you have a Link?

    ReplyDelete
  15. Atlantic coast and Hudson Bay are warm, but Pacific coast is a bit cooler than normal.

    http://www.ncdc.noaa.gov/oa/climate/research/sst/weekly-sst.php#animate

    ReplyDelete
  16. There are a couple of ships in eastern Hudson Bay today northeast of Churchill. They were reporting water temperatures of +9-12C. Not sure how that compares to normal in that area.. but I assume it's above normal.

    ReplyDelete
  17. Hi Rob, I have been looking at Spotwx and their temperatures for the next few days and I do notice that their is humidity added in for Wednesday with the GFS, with severe weather likelihood in the evening overnight. There also appears to be a low pressure system crossing Manitoba in the overnight on wednesday with a warm front over the area on wednesday afternoon, could this heat actually be coming up from the states ahead of this system? I think places in the 40C zone is a little overdone. I'd pick the GFS

    ReplyDelete
  18. Very unlikely Mike.

    ReplyDelete
  19. I am not that good at predicting the coming weather when it comes to models disagreeing. I will follow what you guys have to say about this heatwave. That is why I stuck with 2 possible outcomes on my latest blog post, just to be safe. We will know more tomorrow I guess...

    ReplyDelete
  20. This comment has been removed by the author.

    ReplyDelete
  21. Mike..

    There is a big discrepancy between the NAM and the GEM in regards to dewpoints over southern MB Wednesday afternoon. NAM dries things out substantially in the afternoon with dewpoints dropping towards 10C.. likely explaining their hotter max temps for us. GEM keeps us more moist with dewpoints in the teens Wednesday, which would limit the heating potential somewhat. We have a good southerly flow developing Wednesday, and looking to the south, there is still a good area of mid teen dewpoints in the midwest that will likely be advected north over us. So I think that the NAM may be overestimating the drying, and the GEM has the better handle on the low level moisture, although there will likely be some drying in the afternoon with some mixing. Regardless, it will be too warm aloft to generate anything on the cold front Wednesday night.. with perhaps some activity further north over central MB.

    ReplyDelete
  22. If it's any consolation Mike, CBC Winnipeg is still forecasting that cold front with possible showers for Thursday.

    ReplyDelete
  23. I think anything higher than 37 is a bit too much. 35 seems reasonable, wouldn't be a surprise to see 36 here.

    ReplyDelete
  24. NAM still showing high thirties, despite the fact it's now giving higher dewpoints than it was showing yesterday.

    ReplyDelete
  25. Yeah, I'm thinking 35c is a good estimate for Winnipeg Wednesday given the strong southerly flow, and mid teen dewpoints. It'll be interesting to see how hot it gets over SW MB on Wednesday over the Melita, Virden, Brandon, Killarney regions where 850 temps are the warmest (up to 29C) and dewpoints are lower. Highs of 38c quite possible in those areas... with an outside chance of a 40C reading in some spots if the dewpoints dry out enough. 38C forecast for Minot and much of western ND Wednesday.

    ReplyDelete
  26. 29.9 at the airport so close to 30!

    ReplyDelete
  27. I guess we won't have our 30 today. It went down at the airport to 29.6.

    ReplyDelete
  28. Observations have been cut for many places in Canada once again today. Do you know what's going on Rob?

    ReplyDelete
  29. The Ensemble (NAEFS) mean is below 30C tomorrow, and the max only about 32C. Going back to previous ensemble runs the mean stays below 30C and the max struggles to even reach 31C. Experience is that the Ensemble blows for anything but forecasting a hum-drum average day.

    ReplyDelete
  30. @Anon. EC is in the process of removing a legacy program called CODECON which runs between some weather stations and the data archive, converting the station data to a decipherable format. I'm guessing they didn't realize how many other dependencies there were and are having issues. Just a guess.

    ReplyDelete
  31. LOL. Accuweather is forecasting 31C tomorrow, with a RealFeel of 30C. Currently they are showing 29C with a RealFeel of 28C.

    Windchill at these temperatures?! Accuweather - "The World's Weather Authority".

    ReplyDelete
  32. Max of 30.1C at YWG airport today.. our 19th 30C day of the summer. Add 5C to our temp for tomorrow..

    Hot spot in MB today was 32.1C in Cypress River, south of Brandon. (I'm discounting that suspect 35C at Victoria Beach.) Canadian hot spot was Coronach SK at 36.3C

    ReplyDelete
  33. WOCN11 CWWG 282023
    Special weather statement issued by Environment Canada at 3:23 PM CDT
    Tuesday 28 August 2012.
    ---------------------------------------------------------------------
    Special weather statement for:
    =new= City of Winnipeg
    =new= Steinbach - St. Adolphe - Dominion City - Vita - Richer
    =new= Selkirk - Gimli - Stonewall - Woodlands - Eriksdale
    =new= Dugald - Beausejour - Grand Beach
    =new= Portage la Prairie - Headingley - Brunkild - Carman
    =new= Morden - Winkler - Altona - Emerson - Morris
    =new= Bissett - Nopiming Provincial Park - Pine Falls
    =new= Whiteshell - Lac du Bonnet - Pinawa
    =new= Sprague - Northwest Angle Provincial Forest
    =new= Brandon - Carberry - Treherne
    =new= Dauphin - Roblin - Winnipegosis
    =new= Minnedosa - Neepawa - Russell - Riding Mountain National Park
    =new= Killarney - Pilot Mound - Manitou
    =new= Melita - Boissevain - Turtle Mountain Provincial Park
    =new= Virden - Souris
    =new= Ste. Rose - McCreary - Alonsa - Gladstone
    =new= Swan River - Duck Mountain - Porcupine provincial forest
    =new= Arborg - Hecla - Fisher River - Gypsumville - Ashern
    =new= Berens River - Little Grand Rapids - Bloodvein - Atikaki
    =new= Poplar River.

    Near record temperatures and humid conditions for Wednesday.

    ---------------------------------------------------------------------
    ==discussion==
    A system tracking into Central Manitoba will bring hot temperatures
    and humid conditions into most of Southern Manitoba on Wednesday.
    By Wednesday afternoon breezy south winds will push temperatures in
    the low to mid thirties while humidex values climb into the upper
    thirties. The highest humidex values are expected over the Red River
    Valley and Interlake regions where values will be approaching 40. A
    cold front will slide eastward across the area late Wednesday
    bringing isolated thunderstorms Wednesday night and slightly cooler
    temperatures for Thursday.

    End

    ReplyDelete
  34. Nam is saying 32C for Friday!

    ReplyDelete
  35. No kidding... we could possibly be talking about more 30s Friday and Saturday. Hard to believe we're only a couple days away from September.

    ReplyDelete
  36. Winnipeg Forecast Roundup for tomorrow:
    Accuweather: 31
    00Z GEM-REG: ~32
    The Weather Network: 32
    18Z GFS: ~32
    CTV Winnipeg: 32
    Euro (yr.no): about 32.5
    CBC Manitoba: 33
    12Z GEM-GLB: ~33.5
    Environment Canada: 34
    Weather Underground: 34
    Global Winnipeg: 35
    Weather.com: 35
    02Z RAP: 35.8 by 3pm (so ~36-37 high)
    00Z NAM: 36.9

    ReplyDelete
  37. Thanks for the roundup Garth. REG GEM has been showing a cool bias with Winnipeg temperatures lately.. with SCRIBE high temps almost consistently 2-4C too low compared to actual highs. We hit 30C today, and tomorrow we should be a good 5C warmer, but SCRIBE still going with only 30-31C for us. Odd.

    ReplyDelete
  38. Yes Rob. This morning the GEM-REG and SCRIBE matrices are still the 'coldest' (31-32C). The latest RAP tops out at 37.6C, but it's too warm for Winnipeg.

    ReplyDelete
  39. Wow. Lots more forecast battles coming up in the next few days. Friday has already been mentioned (CBC has 25C, but many others up near 30C) and Sunday the GEM has 35C!!, EC public forecast is 31C, The Weather Network has 30C, but CBC is only 24C.

    ReplyDelete
  40. Already 25C (humidex of 31C) in Dauphin at 8AM.

    ReplyDelete
  41. WOCN51 CWWG 291335
    Humidex advisory
    Issued by Environment Canada
    At 8:35 AM CDT Wednesday 29 August 2012.
    ---------------------------------------------------------------------
    Humidex advisory for:
    =new= City of Winnipeg
    =new= Steinbach - St. Adolphe - Dominion City - Vita - Richer
    =new= Selkirk - Gimli - Stonewall - Woodlands - Eriksdale
    =new= Dugald - Beausejour - Grand Beach
    =new= Portage la Prairie - Headingley - Brunkild - Carman
    =new= Morden - Winkler - Altona - Emerson - Morris
    =new= Bissett - Nopiming Provincial Park - Pine Falls
    =new= Whiteshell - Lac du Bonnet - Pinawa
    =new= Sprague - Northwest Angle Provincial Forest
    =new= Brandon - Carberry - Treherne
    =new= Dauphin - Roblin - Winnipegosis
    =new= Minnedosa - Neepawa - Russell - Riding Mountain National Park
    =new= Killarney - Pilot Mound - Manitou
    =new= Melita - Boissevain - Turtle Mountain Provincial Park
    =new= Virden - Souris
    =new= Ste. Rose - McCreary - Alonsa - Gladstone
    =new= Arborg - Hecla - Fisher River - Gypsumville - Ashern.

    Humidex values expected to surpass 40 in a number of locations
    This afternoon.

    ---------------------------------------------------------------------
    ==discussion==
    A system tracking into Central Manitoba will bring hot temperatures
    and humid conditions into most of Southern Manitoba this afternoon.
    Breezy south winds will push temperatures into the low to mid
    thirties while humidex values will climb into the upper thirties and
    surpass the 40 mark over a number of areas. A cold front will slide
    eastward across the area late in the day bringing isolated
    thunderstorms this evening and slightly cooler temperatures for
    Thursday.

    This is an advisory that high humidex values are expected in these
    regions. Monitor weather conditions and listen for updated
    statements.

    End

    ReplyDelete
  42. Quite late in the summer for humidex advisories!

    ReplyDelete
  43. 27C (humidex of 34C) at 10AM in Dauphin...

    27.8C in Estevan, Saskatchewan right now at 9AM

    ReplyDelete
  44. NAM is giving Winnipeg a high of 36°C Saturday.. It brings 850 mb temps slightly cooler than today (still mid twenties); however it also gives us a southeast wind once again which could keep our temps lower again, similar to today. Wow, we're still dead smack in the middle of summer it seems!

    ReplyDelete
  45. The models are going a bit wonky, not knowing how to deal with the heat at this time of year. NAM actually has 37 for Saturday, GLB GEM has 35 for Sunday.

    ReplyDelete
  46. This is craziness...

    Humidex of 37C in Morden, Manitoba at 11AM...

    31.4C in Estevan, Saskatchewan at 10AM... I repeat... 10AM

    ReplyDelete
  47. Don't forget SK isn't on daylight savings. 10AM in Estevan is 11AM in MB.

    ReplyDelete
  48. LOL. Choose the default Winnipeg location in The Weather Network, and it says we're only 26 C. I wonder which station they are using.
    http://www.theweathernetwork.com/weather/camb0244

    ReplyDelete
  49. The Kindle Fire/RIM Appversion Has 29C

    ReplyDelete
  50. 33.1C in Estevan, Saskatchewan at 11AM!

    Scorching in Manitoba as well... humidex of 39C right now in Carman and Portage.

    ReplyDelete
  51. Humidex 40 in Winnipeg.

    And it's pretty clear that the humidity is keeping our temperatures lower than they could be. Just look at Brandon; the temperature rose by 4°C in 1 hour to 35°C, as the dewpoint dropped from 19°C to 13°C. Brandon's the province hotspot at the moment as a result.

    ReplyDelete
  52. 34.5C in Brandon right now!

    Winnipeg, Carman, Morden and Portage with a humidex of 40C as of 1PM.

    ReplyDelete
  53. Severe thunderstorm watches just issued by EC for areas west and northwest of winnipeg and into eastern SSK.

    ReplyDelete
  54. XWG, the co-located auto station at YWG, was 33.2C at 1pm.

    ReplyDelete
  55. 34/20 for YWG @ 2 PM.. with Td's still holding up making for a tough combination of heat and humidity. Note winds at Brandon have veered to SSW allowing for better mixing.

    Daniel

    ReplyDelete
  56. in Brandon right now!!!

    Winnipeg and Portage with a humidex of !!!

    ReplyDelete
  57. 36.0C in Brandon right now!!!

    Winnipeg and Portage with a humidex of 41C!!!

    ReplyDelete
  58. Humidex is 42C in Winnipeg right now!

    ReplyDelete
  59. Just reached 35.0°C in south end at my place. JJ

    ReplyDelete
  60. I'm looking for a 35.1 please.

    ReplyDelete
  61. Dauphin the current official hot spot in Manitoba, and Canada, at 37.4C.. with Brandon close behind at 36.5C. Western areas have benefitted from lower dewpoints in the 10-13c range to help get that extra surface heating. Still doing pretty well here in Winnipeg at an even 35C.. could go up another degree or so by 5 pm before temps start dropping.

    ReplyDelete
  62. Impressive heat south of the border as well with 112F (44.5C) at Chamberlain and Winner SD.

    ReplyDelete
  63. And the winner is:
    NO - Accuweather: 31
    NO - 00Z GEM-REG: ~32
    NO - The Weather Network: 32
    NO - 18Z GFS: ~32
    NO - CTV Winnipeg: 32
    NO - Euro (yr.no): about 32.5
    NO - CBC Manitoba: 33
    NO - 12Z GEM-GLB: ~33.5
    NO - Environment Canada: 34
    NO - Weather Underground: 34
    YES! - Global Winnipeg: 35
    YES! - Weather.com: 35
    NO - 02Z RAP: 35.8 by 3pm (so ~36-37 high)
    NO - 00Z NAM: 36.9

    Two forecasts which were completely auto-generated. Dumb luck. EC's 34C was close enough in my books.

    ReplyDelete
  64. Oh, and you too Rob, since you called 35C yesterday!

    ReplyDelete
  65. For those who follow Ensembles, even today's 12Z NAEFS Ensemble maxes out at about 32C. So according to the method some propose you use Ensembles, there was a 0% chance of our 35C happening.

    ReplyDelete
  66. Ensembles will never do well with extremes.. since they're an average of a number of runs which will tend to give you more conservative values. They won't be as right, but their benefit is they won't be as wrong either, especially as you get out in time. Ensembles are especially helpful with precip forecasts when models can be all over the place with QPF values.

    That 32C forecast for Winnipeg on Friday is odd.. seems too warm given the setup, and 850 temps of 15-16C. That would support highs of 27c. 32c more likely on Saturday as the warm sector moves in as the NAM suggests.

    ReplyDelete
  67. Hey Rob, do you have an official high for today? Did we creep higher than 35.0°C?

    ReplyDelete
  68. Correct Rob, however CMC misrepresents the utility of ensemble forecasting, in my uneducated opinion. Check this document.
    http://collaboration.cmc.ec.gc.ca/cmc/cmos/publications/ensemble_weather_forecast_example_e.pdf

    A quote: "Arthur knows that the probability the the temperature reaches or exceeds 25C is the number of forecasts confirming this scenario. For example, if 11 of the 21 forecasts indicate that the temperature will equal or exceed 25C, the chance of this happening is there 52% (11/21)".

    Wrong. This statement makes a huge (and false) assumption that the ensembles members encompass all possible scenarios. However as happened today (and happens quite often), every single ensemble member can be wrong and an event with 0% chance actually occurs.

    However it does have some utility if used properly, as you say.


    ReplyDelete
  69. Brad.. YWG hit a high of 35.4C today... not a record, but tying July 29th as the hottest day of the year in Winnipeg. So congrats to those who chose 35-37c in the poll! Dauphin was the provincial and national hot spot at a record 37.9C... 100F!!

    ReplyDelete
  70. Goodness, still a sauna at 30°C at 10 PM. Any money we saved on heating last winter has been used for air conditioning this summer..

    ReplyDelete
  71. Garth.. Yes, I see what you're saying. If none of the ensemble members are predicting a high of 35C, but are converging around 30c, is there really a 0% chance of hitting 35C? One would think that there's a certain range of outcomes possible around a predicted ensemble value, within 5c say, that can occur, albeit with decreasing probability as you get away from the predicted value. It's difficult to say what that range is, and would vary depending on the ensemble spread. Note also that the NAEFS ensembles are based on a coarser model, and don't have the resolution to see extremes as well as higher resolution short term models.

    ReplyDelete