Thursday, February 19, 2009

Province releases preliminary flood outlook

The Manitoba provincial government released its first spring flooding outlook for southern MB today, and preliminary data suggests there will likely be significant flooding on the Red River this spring. A wet fall, cold winter, heavy snowpack south of the border, and a rare February rainfall event has led to above average soil moisture conditions in the Red River watershed. (click here for an aerial survey of snowpack water content as of early February) Based on average weather conditions over the next 6-8 weeks, a flood comparable to that of 2006 or 1996 will likely develop on the Red River this spring, which will cut off Morris and much of Hwy 75 for at least 1-2 weeks. Unfavourable weather over the next 2 months (i.e. wetter than normal) would produce a flood about 2 feet higher than 2006, but still well below that of 1997. Transportation on Hwy 75 would be cut off for 2-3 weeks in this scenario. Currently however, the risk for a 1997 flood is less than 5%.

Note this flood outlook is very preliminary and could change significantly based on weather conditions over the next 6-8 weeks. However, based on "average" weather conditions through the end of March, it appears there will be some significant flooding on the Red this spring.


  1. All of this and we have not had a "BIG" snowstorm yet!

    I have a feeling winter is not over yet!

    Does anyone see if we are heading into a stormy weather pattern next week???

  2. Considering the flood seems a certainty I hope it won't be very serious. It must be stressing to know you'll be flooded with such anticipation, especially if you live in the areas that will be under water...

    Best of luck for you boys!

  3. Despite all the flooding news, I think the situation probably isn't as bad as we think. For the most part 2006 wasn't really a bad flood, obviously people had their homes flooded in rural areas, but the towns and cities weren't really in danger. The other downside was that HWY 75 was closed for awhile. However the flood this year probably will be even less significant than 20006, even if the water are a bit higher.

    If a 1997 type flood were to occur, it also wouldn't be anywhere near as bad as the flood in 1997. Most cities and towns in Manitoba have permanent dikes several feet higher than the 97' levels. Winnipeg now has a floodway with a greatly increased capacity. However if a 97' type flood did occur, it would no doubt cause extensive damage outside of towns, and would close highways. A flood is not something to be made light of, but we have to remember that our flood defenses are very strong today, and most Manitobans living in the Red River Valley don't have much to worry about this year.

  4. Anyone see the potential for a snowstorm on Tuesday ???
    The GFS is showing some snow with quite a bit of wind on Tuesday!
    Whether that come true and guess we will see!

    It will get quite cold after!

  5. I think Scott is right. My understanding of the forecast is that the potential is high, but as long as we have a gradual melt and no significant precipitation, things will be OK.

    It's just a pet peeve of mine, but I wonder how rain fall or snow fall became "rain events" and "snow events?" :) Do we have "lunch events" or "breakfast events?" My theory is that the replacement terminology was invented by bureaucrats to make these phenomenons sound more important. Sorry, just one of those things that annoy me. :)

  6. So any takers on what is going to happen tomorrow for Winnipeg?

  7. Looks like we're going to get a general snowfall over southern MB Tuesday into Tuesday night. GEM indicating a general swath of 5-10 cm across the Red River valley including Winnipeg. For Winnipeg, area of snow spreads in from the west by midday or so, increases during the afternoon into the evening, then tapers off Tuesday night. Get ready to revisit those winter driving skills by the drive home tomorrow..

  8. ahhhh.....

    10 CM of snow for Winnipeg and Red river valley tomorrow.
    Lets make it our "BIGGEST" snowfall of the year!

  9. Let me restate as a question!!!

    if Winnipeg gets 10 cm of snow tomorrow will that be our biggest snowfall of the winter????

  10. I think it will be if we get 10cm. I know we had a couple of 8cm snowfalls and I would have to say I think they were a very stretched 8cm.

  11. The term "event" is often a convenient way to reference extreme or record meteorological/ climatological occurrences. The "rainfall" of earlier this month certainly qualifies as an 'event' in my book. If the term is over used one should blame the ratings driven media rather than government bureaucrats.

    GEM is more bullish on precip for tomorrow's system with around 7 mm water equivalent while GFS depicts 2-3 mm. Given the very impressive thermal gradient and possible frontogenic forcing the system will work with.. do you see the potential for banding (slantwise convection). Perhaps this is why GEM is more bullish on QPF?

    Very cold air mass progged by GFS to move down after the disturbance passes. Upper level cold core (850 temps initially at almost -30 C) and associated surface high (1035ish mb) will move down from central Alberta. Friday morning looks brutally cold with a light NW flow and the high centered just to out west.

    A couple of wildcards... how much fresh snow cover will be in place... and how much modification will occur with the higher sun angle. GFS hints at some decent modification with the high dropping south thru Alberta and then moving east. Minus 40 at Edmonton intl airport towards Saskatoon is certainly a possibility Wednesday/Thursday mornings. I hope for no colder than -34 C at YWG for Friday morning.

  12. That same cold air mass that Daniel is talking about (the other Daniel) is going to bring -55 to -60 C windchill tonight into tomorrow for area around Rankin Inlet and Baker Lake!!

    OUCH!!!! That's gonna hurt!

  13. These cold air events are becoming tiresome. I'm hoping a spring event will come our way soon.