Sunday, June 28, 2009

Heavy rains soak southern /eastern MB

A strong storm system brought heavy rainfall across southern MB June 26-27th. The storm began as showers and thunderstorms Friday the 26th with heaviest amounts across the southern RRV and southeast MB. The system then wound up as an intense low pressure system over northwest Ontario on the 27th, bringing a soaking wind-driven rain over eastern MB, with the heaviest rainfall over the Interlake and Whiteshell areas. Here is a summary of rainfall amounts over the past 2 days.

Official observations (EC)

Location storm total

Brandon - 11.0 mm
Carberry - 13.2 mm
Oakpoint - 24.6 mm
Pilot Mound - 27.8 mm
Winnipeg - airport - 31.2 mm
Portage la Prairie - 33.8 mm
Delta marsh - 35.2 mm
Deerwood - 36.4 mm
Sprague - 40.6 mm
Morden - 47.0 mm
Fisher Branch - 48.2 mm
Winnipeg - the forks- 50.6 mm
Gimli - 67.7 mm
Gretna - 72.2 mm
Carman - 75.2 mm
Great Falls - 92.0 mm
Pinawa - 94.6 mm

Unofficial observations

Location storm total

Altona - 85.0 mm
Arborg - 75.0 mm
Dugald - 78.4 mm
Elm Creek - 62.0 mm
Landmark - 99.8 mm
Letellier - 76.4 mm
Marchand - 92.7 mm
Morris - 85.2 mm
Portage la Prairie - 47.2 mm
Selkirk - 84.4 mm
St. Pierre - 101.8 mm
Starbuck - 36.4 mm
Steinbach - 82.0 mm
Teulon - 67.8 mm
Treherne - 55.8 mm
Winnipeg north - 59.0 mm
Winnipeg west - 35.0 mm
Winnipeg south - 55.0 mm
Winnipeg southwest - 38.8 mm
Woodlands - 48.8 mm


  1. Storm total at my site is 86.2mm. That is about 86mm more than I needed.

  2. Here's an interesting fact. These are may rain totals in June for 2008 and 2009:

    June 2008: 114.4mm
    June 2008 (up to 28th): 114.4mm

  3. Rob!

    What was the highest wind gust that was recorded yesterday in Winnipeg???

    There was quite a few large branches blown down from the wind yesterday!!!

  4. Peak gust yesterday at Winnipeg Airport was 69 km/h. Highest gust at Victoria Beach was 102 km/h. What's really amazing is that even forested Pinawa had a gust to 82 km/h yesterday. No wonder there were power outages..

  5. Gotta love how YWG *always* ends up on the very low end of amounts. I suspect June precip will be significantly below normal there. Is there a convective black hole over NW Winnipeg? ...perhaps some undercatch?

    The last decade has seen multiple extreme precip events affecting the southern RRV, SE Manitoba, and to a lesser extent the Interlake. These are occurring in the warm convective seasons and fortunately have not affected most of Winnipeg (except southern and eastern areas of the city).

    I believe there is some kind of forcing mechanism that favors the same precip pattern over and over again.. perhaps related to orientation of LLJ. Any other thoughts or comments?


    Looking ahead to this week... hopefully we can squeeze in some sunny, pleasant weather as cool high pressure tries to ridge down. We will be between two massive upper lows, one over Northern Alberta and the other centered about the Great Lakes. I am a bit concerned that deeper moisture may back in around the eastern low off the Atlantic (of all places) and plague us with clouds etc.

    Eventually, GFS shows upper low over N Alberta flattening out the upper ridge which tries to establish itself over us. This will allow a shortwave to pass thru and interact with moisture/ instability... giving another round of tstorms to the area.

  6. Hey everyone!

    Go to Winnipeg Free Press website and take a look at the latest videos!

    There you will see a video on how strong the winds were on the beaches this weekend!

  7. Clip added.. thanks Daniel. Looks like cottage country really got hit hard with those winds.

  8. Chris - St.Vital10:39 AM, June 30, 2009

    Looks like Scott was right about the models showing a cool down after the last low pressure. European models show the slightly cooler than normal trend continuing into the 3rd week of July where they are predicting another warm-up. Those north winds almost require a jacket.

  9. Rob!
    The forecast for Southern Manitoba show sunny skies for the next 7 days right across the board!

    Is there ANY chance of a thunderstorm in the next week???

  10. Chris...

    I again would caution against putting much stock in long range model solutions. They are not very accurate despite the fact they are pushed by private forecasters (who have financial incentive to do so). I had highlighted the potential return to below normal temps only using past experience and analogue years like 1996 and 1997. Several forecasters had earlier called for an unbroken stretch of above average thru August for Southern Manitoba.

    Daniel P...

    As Rob has stated many times, the extended forecasts from EC are based on a single deterministic run of the GEM model... take them with a big grain of salt. We will have the potential for convection during Thursday. The Alberta low will flatten the upper ridge off to our west sending shortwave energy thru us. Amount of moisture return and instability pooling ahead of associated surface trough are in question however.

  11. Chris - St. Vital5:37 PM, June 30, 2009


    I agree with you to an extent that long range models can't be relied upon. However, for someone such as myself who is fascinated by the weather but took a different career path, relying somewhat on long range models is one of a very few options that won't cost thousands of dollars and time in university.
    On that note, my brain is a sponge and if you could give some insight into interpreting different weather models, I am all ears and willing to learn.
    Thousands of dollars and university isn't really an option.

  12. Chris..

    I would recommend the following (just my opinion):

    1. Use many different models and try to take a consensus. Don't rely on one model for a long-range forecast. Use as many as possible and try to get a sense of where things are going.
    2. Don't trust a model that is flip-flopping. Obviously you won't get the exact forecast from run to run, but if the overall pattern stays the same for a number of runs, chances are it is a good forecast. On the other hand, if the model can't make up its mind, wait it out...there isn't much else you can do.
    3. Don't put too much stock in a single run. I have seen forecasts collapse in a 6 hour period. At 7a.m., the models are showing a major blizzard, and at 12p.m., they show nothing but a chance of flurries. This goes with point #1. Try to get a sense of what will happen from a number of models...and don't trust runs just because they are two or three days away.
    4. Be critical of the models. Even if a model keeps showing the same forecast, be critical. Ask yourself whether the solution makes sense...use actual analysis tools to verify your thoughts.

    Those are my ideas...I'm sure others will have plenty good tips for you too.

  13. Models are an essential part of any forecast. We are not fast enough to make the massive number of calculations necessary to model the planet's atmosphere. However, the models accuracy in predictions decreases significantly with time. Differences in solutions become more and more amplified between ensemble members or different deterministic models thru time. Anything past two weeks is suspect to me.

    As Scott mentioned, you should always try to look for agreement between model solutions and consistency from run to run within each model. With experience you will learn to look for particular features or signatures such as warm/moist advection associated with LLJ, shortwaves in the 500 hPa vorticity pattern, clouds in the RH fields, etc.

    A university education is indeed a big investment.. with unfortunately no guarantee of return. I always try to share my knowledge with others, and this is the reason I outline and analyze our weather pattern as often as time permits.

  14. Tricky convective forecast for tomorrow with subtle surface pressure pattern...

    Upper flow turns more zonal allowing upper level energy to move thru us tomorrow. Mid level moisture finally moves in from the west aswell on Thursday. If clearing can occur by afternoon, I would expect convection to fire up somewhere over Southern Manitoba. Models wash out surface trough as it moves east.. so watch for possible initiation anywhere along the Manitoba Escarpment or the lakes.

    I think GFS is underestimating surface dewpoints and consequently CAPE tomorrow... don't be surprised to see surface Td's around 15 C (already 13 C today). This would likely yield atleast 1000 J/kg of SBCAPE. Depth of moisture also looks pretty good with higher 850 hPa Td's sloshing in from the west. There will be fairly good unidirectional shear above 700 hPa to sustain any convective lines or clusters that form.

  15. Rob the weather man, I just came back from California at that time. This happened two weeks after my magical tour in Disneyland in Anaheim. I shall be there most of the summer to avoid extreme weather in Manitoba.

    Differences of weather between Manitoba and California are here summers can be hot, dry, humid or stormy. In California, precipitation are totally rare. I should be in LA or San Francisco to avoid wet Manitoba weather.