Saturday, November 27, 2010

More snow moving in Monday with increasing north winds..

More snow is on the way over southern Manitoba early next week as a low pressure system slowly tracks across the Northern US plains. Snow from this system will spread over southern Manitoba on Monday and taper off Monday night over SW Manitoba but persist into Tuesday closer to the Ontario border. As this system intensifies to our south and east, northerly winds will be increasing by Monday afternoon producing areas of blowing and drifting snow especially through the Red River valley Monday night into Tuesday. General snow amounts look to be in the 5-10 cm range with this system, but models are hinting that there may be locally higher amounts over higher terrain of southwest Manitoba as well as closer to the Ontario border where snow may continue into Tuesday. Stay tuned on this developing system as the snowy November of 2010 continues. (image shows Canadian Global model precipitation forecast valid noon Monday (NOAM sector). See also HPC snow probability maps)

32 comments:

  1. That is just SICK to think that in one week and a half we could almost have as much snow as all of last winter!!

    Payback for the easy winter last year...LOL

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  2. Maybe we'll get off easy the rest of the winter? Fat chance of that...

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  3. Ensemble is giving an 80-90% chance of at least 5mm of precip over the RRV and SE MB with this next storm. Based on the expected snow ratio, that would easily put snowfall amounts in the 5 to 10cm range.

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  4. Heavy rains and lots of snow so far this year have Winnipeg approaching a record for annual precipitation.

    Environment Canada added up all of the moisture from rain and snow and got a total of 710 millimetres. A check on the record books shows the amount is noteworthy.

    "When you add all of those millimetres of moisture together in the whole year, right now we are the fourth wettest year ever," John Sauder, CBC Manitoba's meteorologist, said Friday.

    Sauder said Winnipeg only needs an additional 14 millimetres of precipitation to break the existing record, set in 1962.

    And it's likely the city will get those millimetres, since a lot of snow can fall in the five weeks left in the year, he said.

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  5. Although the risk of spring flood is Extremely High, 1962-63 is an excellent example of what can go right between now and spring. Despite precipitation records the 63 flood was a non event, similar to our recent November high water mark.

    The flood that wasn't
    !962 record precipitation 723mm, including in NOV. 36mm of rain and 21.3 cm of snow.
    Very Wet April (33mm rain on April 7th PART of 75mm BY April 16th)

    The reason(s)
    4)Major heat in 1962 with the rain
    3)Sept and Oct were warm and dry
    2)December 62 Jan & March 63 very dry.
    and the biggest reason
    1)Spring came early.

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  6. What is the chances of seeing blizzard conditions in southern Manitoba on Monday with the falling snow and winds north 40 - 60 ????

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  7. Good post Jim.. A wet year does not automatically equate to a major flood the following spring.
    Of the top 10 wettest years in Winnipeg, none were followed by a severe spring flood. It's important to realize that ground saturation conditions are only one piece of the puzzle in assessing the overall flood risk. Winter snowpack and spring melt conditions are more critical components in determining how severe spring flooding may be. That's why it's still too early to say that a major flood is a slam dunk next spring..

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  8. Environment Canada is saying about 2-4 cm tomorrow. Is that accurate based on what people here are looking at?

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  9. Latest guidance is showing snow developing in Winnipeg Monday morning and then easing off in the afternoon before another wave of snow moves in by Monday evening as the main low intensifies to our south and east. The question is how far west this secondary snow shield will be as the storm system tracks eastward. Best chances for 10 cm or more will be east of the RRV, with lesser amounts to the west. Right now looks like Winnipeg may see 2-4 cm Monday with another 2-4 cm Monday night.

    Increasing northerly winds Monday into Monday night will make for poor visibilities with falling snow, so there is a potential for blizzard-like conditions in the valley, especially by Monday night coincident with the second wave of snow and the stronger winds. Depending on how far west this second wave of snow spreads and how quickly it moves out Monday night into Tuesday will determine if we see true blizzard conditions in the valley, or just blowing snow over open areas.

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  10. Incredible how much warm advection occurring out ahead of this system... mild air flooding across Minnesota as far NW as Fargo, which is sitting at a beautiful 4 C in spite of snow cover. Meanwhile a ridiculous -9 C at YWG under the influence of a shallow layer of cold air, NE flow and trapped moisture.. what is wrong with this place? Models show above 0 C 850 hPa air reaching into Manitoba later this afternoon and still hinting at some mixing. However, I suspect we will have to wait for the system/trough to get closer for temps to move up a bit. In fact warm air dumb-belling around the low from NW Ontario will have to watched initially as the system moves in.

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  11. LOL!!!
    I'm getting the impression that Daniel does not like this city and it's cold winter's!

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  12. ECMWF model is showing potential for blizzard conditions on Tuesday. Forecast surface winds are 25 to 30kts (45 to 55km/h), with gusts of 30 to 40kts (55 to 70km/h). Combine that with 5cm or more of snow on Monday and you'll get blizzard conditions. The main question is whether or not that model is correct with those wind speed predictions. Other models seem to be giving fairly similar predictions for 850 and 925mb winds, so it will be a question of mixing.

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  13. Latest guidance is giving Winnipeg only a couple of cm with Monday's first wave of snow.. then developing most of the main snow east of the Ontario border Monday night into Tuesday as the system intensifies to our southeast. Based on that, I've gone with 2-5 cm for Winnipeg in the poll. Poll consensus is at 7.3 cm. Poll ensemble has underestimated each of the past 3 snowfalls, let's see if the trend continues with this one..

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  14. Latest GFS gives SE MB 12-14mm of storm total precipitation by late Tuesday...that would put snowfall amounts in the 10 to 20cm range. Very tough to say if this will be correct, given that most other models are much lighter on amounts. However, it will bear watching.

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  15. Looks like Eastern Minneasota is going to bear the brunt of this storm!
    Heavy area of snow heading just to the east of the red river valley!

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  16. Difficult to measure snow amounts today due to the wind.. but I'd guess around 2-4 cm of new snow today. An observation of 4 cm at the airport as of 6 pm. Lots of drifting which made it seem like more.

    Radar continues to show some light snow persisting over Red River valley with some locally heavier banding evident.. while heavier area of snow spreads over NW Ontario associated with main low and trof. Maybe another couple of cm for us in the valley, although winds will continue to create problems with blowing and drifting snow tonight into Tuesday.

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  17. Sustained winds up to 45-50km/h in the southern RRV. There is a chance for a ground blizzard in this area overnight into Tuesday.

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  18. Hi

    a general 1-2 inch snow in the red river valley of ND/MN tonight probably closer to the 1 than the 2, but as others have said very hard to measure as the old stuff is drifting with the new stuff. Vsby at times with the snow falling has been reported to 100 yards in the country. Not a blizzard but definitely not a good night for travel.

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  19. So as soon as the numbers are available, did CYWG break a Nov. snowfall record this year??

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  20. Blowing snow warning issued for areas of southern Manitoba!

    Rob is that a new warning for Manitoba???

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  21. Daniel..

    Yes, this is the first year blowing snow warnings are being issued for the Prairies. They are meant to cover cases where there are significant areas of blowing snow reducing vsbys below 1/2 mile (800 metres) with winds of 30 km/h or more, lasting for 3 hours or more. A blizzard warning would be issued for more widespread vsbys below 1/4 mile (400 metres), winds of 40 km/h or more, lasting for at least 4 hours. (i.e. the most severe cases)

    In today's case, the blowing snow warning was issued for southern Red River valley due to the stronger winds there hence the more widespread blowing snow. Local areas of blowing snow however will be a problem today anywhere in exposed areas. Luckily, not much in the way of falling snow to make for worse more blizzard like conditions.

    Officially, 6 cm of snow yesterday at the airport. I'm calling it 5.. but very difficult to give a truly accurate number due to the winds. So congrats to the 5-10 cm poll group (which was the majority of responses) Ensemble was very good too at 7.3 cm.

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  22. Anon..

    Winnipeg airport no longer takes snowfall measurements (at least, not consistently that make it into the climate archives) Snowfall recording program stopped at the airport in 2003.

    So official snowfall stats for Winnipeg are based on volunteer measurements, such as myself in Charleswood. After yesterday's snowfall, my total for the month is 55.6 cm. Using my data and comparing to past Winnipeg airport data would reveal this would be the 8th snowiest November on record (since 1872) 1955 was the snowiest with 80.3 cm, followed by 1958 at 77.2 cm. This however will be the snowiest November since 1996 (62.8 cm)

    Note however that it's not really accurate to compare my snowfall data with past airport data, since we're two very different locations (airport is more exposed) However, that's the best we can do given the lack of snowfall obs from the airport.

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  23. Messy situation in Steinbach. All sidewalks and boulevards are drifted over. Lots of snow and ice on the streets with heavy blowing snow in open areas. I haven't measured total snow accumulation yet, but it looks to be in the 5 to 10cm range. Steinbach airport weather station only reporting winds of 25 G 50, which seems low (although I believe that weather station always underestimates the wind speed). Nevertheless, winds here are not as strong as in Emerson, where winds of 55 G 65 are certainly causing a ground blizzard.

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  24. Yes~
    The webcam out of Emerson is showing near whiteout conditions!!!

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  25. Looks like a blocking pattern is setting up which ensure southern Manitoba stays in a chilly airmass!!

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  26. Look at the temperature at the Winnipeg airport plummet!

    Already near the overnight low at only 5:00 p.m

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  27. Interesting start to Dec Dan P. Continuous cold weather from now to April is the the Major influence over how big the 2011 spring flood in todays Winnipeg Free Press Front Page article will be.

    We've only had one top 7 flood of the last 110 years without continuous below avg monthly weather from Dec to May. Unfortunately that was 2006!

    And Super floods (1824,25,26)(1996,1997) follow 2 or 3 years of it.

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  28. Compare these lists

    Top 10 floods last 200 years or so
    1826,1997,1852,1861,2009,1950,1996,1979,2006, and 1974

    Excluding the 19th century floods we don't have comparable temperature data for
    here is a list (thank you Rob)of top 7 consecutive below average winter temperature individual months. from 1950 to 2009.
    1997 7 consecutive months from Nov 1996 to May 1997 were below average.
    2009 9 months from December 2008 to August 2009
    1950 9 months from December 1949 to August 1950
    1996 8 months from October 1995 to May 1996
    1979 8 months from November 1978 to June 1979
    2006 2 months beginning February (oops)
    1974 7 months from November 1973 to May 1974

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  30. Instead of near record warm Dec Jan (2006), 2010-11 winter looks much more like something between 2006 and 1996 with predicted (TWN) near normal DJF temps or like something more than 1996 if NWS Dan GF etal prediction of below normal DJF is repeated in March and April.

    IF cold continuous weather takes us into May we'll learn to like our Armed Forces all over again. And someday anecdotal evidence will suggest prior to the events of 2009,10,11 Lake Winnipeg didn't start in Pembina.LOL

    Ironic isn't it, our spring pain appears to be dependent on how cold and for how long our winter is.

    With apologies to Dan GF I hope that TWN is correct.

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  31. Reading that free press article this morning "another flood of the century"?
    Looks like they finally got the snowfall amounts right!!!

    Any chance of that storm south of the border affecting southern Manitoba this weekend???

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  32. That storm system in Montana today will clip southwest MB overnight into Friday with some light snow, but main area of snow will track through ND and miss the RRV of Manitoba. Arctic high pressure builds in over the weekend with cold dry weather continuing into early next week. Overall, looks like a quieter and seasonably cold pattern setting up for the beginning of December.

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