Thursday, March 10, 2011

Slick conditions developing Friday with mixed precipitation changing to snow and blowing snow Friday evening

A storm system over the western Prairies is forecast to track through the MB interlake region overnight into Friday bringing a mixed bag of weather over southern MB Friday into Friday night. Milder air in advance of the system will bring some patchy rain, ice pellets or freezing rain over southern MB Friday morning, with slippery conditions likely as rain freezes on contact with colder surfaces. Temperatures are expected to rise above freezing for a few hours Friday afternoon (+1 to +4C range) which will result in some melting of snow and ice. A strong cold front however is expected to push through the Red River valley by late Friday afternoon with snow and blowing snow developing accompanied by strong northerly winds of 50 to 70 km/h. This front will drop temperatures well below freezing Friday evening freezing up any standing meltwater resulting in slick conditions. Snow and blowing snow will bring about 5 cm of fresh snow to Winnipeg and the RRV Friday night with heavier amounts likely north and east of the city. Be prepared for poor driving conditions across southern MB and the Interlake regions especially Friday evening into Friday night as temperatures drop and snow and blowing snow produce poor visibilities. Environment Canada has issued a special weather statement for Winnipeg and southern MB on the potentially wild and wintery weather Friday.

32 comments:

  1. Rob,
    I see that they have Portage La Prairie forecast high for 8 C tomorrow!
    Is that even possible or is that far fetched??

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  2. Daniel,

    The high of +8 seems reasonable for tomorrow. We should get up to +3 or +4 through much of the RRV in the warm sector of this system, and as the trough passes through, winds should switch to westerly in areas near the escarpment. In situations similar to this, we have seen highs of +7 or +8 in areas near the escarpment due to the downsloping of the winds.

    Don't hold up too much hope of it getting much warmer than +4 in YWG, though :)

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  3. The GFS is now showing some intense wraparound precip.
    Which by then the cold air will have arrived and be changed over to all snow.

    5cm of fresh snow seems about right!!!

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  4. As Dan GF noted.. American guidance still more aggressive on a more southerly low through ND.. with heavier snow across southern MB and RRV Friday night. NAM has very little precip over us during the day in the warm sector, but then develops area of moderate to heavy snow behind the cold front Friday evening with 5-10 cm possible Friday night along with strong winds and falling temps. 12z ensemble forecasts indicate 5-10 mm event totals for Winnipeg Friday. Will be interesting to see if that's all snow, or mixed precip ala GEM.

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  5. So it would seem that for a few hours in the early morning things could be very slick, of more concern is when the temperatures plummet and all that standing water freeze!

    Rob, do we issue flash freeze warnings here in Manitoba??
    I know they do in Ontario!

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  6. Daniel,

    We do issue flash freeze warnings here in MB. One of the criteria, and perhaps the hardest to hit here, is a temperature drop that can be averaged out at some point to 12°C / 3 hrs. That's a pretty strong cold front, but tomorrow night would be the best chance we've had in a while at it.

    It's really starting to look like near-blizzard conditions as soon as the cold front blows through YWG tomorrow evening.

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  7. Issued a blizzard warning for the northern RRV late today and tonight....2-3 inches of snow but winds 25-40 kts with whiteout conditions.

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  8. Blizzard warning for Red River Valley!!!
    Very strong winds gusting to 80 km/h! This will be a bad one folks!

    They have a Tsunami warning on Environmetn Canada's weatheroffice website this morning!!! WHOA!
    First time I've seen that!

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  9. You know how bad the whiteout conditions were last month when we got only 2 cm of snow and winds around 65 km/h!

    Close to 10 cm of snow and gusts to 80 km/h ensure whiteout conditions!

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  10. The tsunami watch on EC's site was because a massive earthquake struck NE Japan and consequently caused a tsunami. The magnitude 8.9 earthquake caused major damage and flooded coastal regions of Japan. Strongest earthquake in more than 140 years for Japan. Incredible considering how many earthquakes occur there. Not expecting major flooding or damage here on the coast, just a wave of about 60cm.

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  11. Up to +3 in my yard in Westdale now so I imagine the initial freezing rain is out of the question.

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  12. Checking Brandon's observation at noon time still shows freezing rain so it may take a few hours of rain before the changeover to heavy snow here in Winnipeg..

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  13. Environment Canada did not even hesitate in issuing a blizzard warning for Winnipeg!!
    Usually within the city limits it's hard to get true blizzard conditions with all the structures and trees, but this one could be a doozy!!

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  14. Quite the wall of precipitation directly to our West and also to our south. Looks like Wpg is about to be squeezed....and hit hard in about an hour!

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  15. TransCanada now closed from Winnipeg to the Sk border. Blizzard conds have moved into Portage with 60 to 85 km/h winds and a temperature drop from -2C to -9C past hour. Snow should be pushing into Winnipeg by 6 pm or so, possibly starting off as some light rain, with strong winds and blizzard conditions likely by 9 pm.

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  16. Currently raining in Steinbach.

    We lost about 5cm of snow today in Steinbach due to +7C temperatures.

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  17. Full blown blizzard conditions at Winnipeg as of 7 pm.. Visibility 200 metres at YWG airport, winds NW 59G72 km/h, temp -6C.. a drop of 7C in 30 minutes. It's wicked out there!

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  18. METAR CYWG 120100Z 33034KT 1/8SM R31/1800V2600FT/N SN +BLSN VV001
    M05/M06 A2957 RMK SN8 RVR36 MISSING SLP023=

    SPECI CYWG 120055Z 33032G39KT 1/8SM R31/2400FT/N R36/3500FT/N
    SN +BLSN VV001 M05/ RMK SN8=

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  19. Cold front is through Steinbach now. Wind went from 4km/h to 40 G 60km/h in about 60min. Heavy snow and blowing snow currently in place...HWY 75 and 59 now closed.

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  20. Wind gusts so far .. 89Km in Grand Forks and Cavalier 93 in Altona

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  21. Crazy blizzard....had to go to work which is on the far west side of GF....took 15 minutes to find the right road to turn to. In town itself ok...

    Was discussing among local mets via FB the poor performance of the CMC with this one...way too far north sfc low. Glad the GFS one out.

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  22. Dan..

    Yeah, this event was poorly handled by the GEM.. it basically ignored development of the southern low until yesterday... well after the GFS/NAM.

    As for the blizzard for us, it came in quick but also left quick.. only a couple hours or so of true blizzard conditions last evening here in Winnipeg and areas west.. snow shield went through fairly quickly which kept amounts lower (only about 5 cm or so here - very tough to measure with the strong winds and drifting.. 4.5 mm water equivalent from YWG airport) Blzd conditions lasted longer in the southern valley. Even though it was fairly short lived, roads became very treacherous last night with the sudden freeze and blowing snow, resulting in numerous road closures across srn MB. Overall, a significant storm but not as bad as it could have been had it gone through slower..

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  24. Total of 6cm of snow in Steinbach, along with 1.4mm of rain. Total of 8.4mm of precipitation, with 7mm of that being snow. The snow started out quite wet (since it was changing over from rain) and I don't think it started to accumulate right away - that explains the high snow liquid equivalent.

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  25. Rob!
    I see they have 6 C forecast for Tuesday!
    Is this one of those situations were area like Portage could hit that while Winnipeg sits at around 0C???

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  26. Rob, looking at weather network's forecast for the up coming week it shows 20 - 30 cm for Sunday. Is there a storm brewing of that magnitude?

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  27. I don't know about 20-30 cm, but the GFS is indicating the potential for a storm system coming up from the central US plains and giving southern MB a good shot of snow Sunday into Monday. Too early to give amounts, but ensembles are already indicating 7-15 cm possible which is quite significant for an ensemble estimate this far out. Snowfall amounts will depend on exact track and how much warm air will be drawn into system which may reduce amounts if there's ice pellets or freezing rain mixed in, or even rain. Note that the ECMWF keeps the storm well south of us and tracks it east towards the Ohio Valley.. so still a lot of uncertainty yet. Will be keeping a close eye on it though..

    As far as tomorrow's +7C in Winnipeg.. looks possible as we get a more westerly to SW flow tomorrow along with more sunshine.

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  28. Additional precip late this week. The NWS FGF (Dan GF's Team) Spring Outlook is expecting significant warmup and precip late this week. ...On my name or
    http://www.crh.noaa.gov/fgf/

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  29. Rob did the latest models swing further south for the weekend storm I see EC changed it from periods of snow to 60% chance of flurries

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  30. Daryl..

    The ensemble runs today came in showing Sunday's storm track further south and east which would give less precip to southern MB. We'll have to see if this is a consistent trend, or if models flip back to a more ominous solution for us. For now, it appears that the Dakotas and Minnesota will have the better chance of seeing significant precip from this system, but it will be close enough to keep an eye on. Regardless, it will likely impact the RRV basin with additional precip on top of this week's snowmelt..

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  31. Rob,
    You expecting any widespread rainfall amounts tomorrow or will this be hit and miss showers????

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  32. Looks like an expanding area of precipitation moving into southern MB Wednesday as a weak low moves across the TransCanada, with precip development being enhanced by some good lift ahead of an upper impulse. Looks like areas along and south of the TransCanada will get some rain and wet snow while areas north of the TransCanada through the Interlake and Riding Mtn areas will see mainly snow.. possibly heavy at times. At this point, looks like maybe 2-5 mm of rain for Winnipeg Wednesday becoming mixed with or changing to a couple cm of snow by evening. 10-15 cm of snow may fall to our north Wednesday into Wednesday night. Snowfall amounts will be tricky depending on surface temperatures (will be some melting with near or above freezing temps Wednesday), timing of transition to snow, and elevation issues (heaviest snowfall will likely be over higher elevations to the west of lake Manitoba).

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