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| This is what many roads in southern Manitoba may look like Saturday |
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| Expected storm position valid 6 am Sunday Nov 11th (HPC - NOAA) |
- Precip Phase: Will be an all snow event. With the above storm track, likelihood of mixed precipitation (freezing rain/ice pellets) is reduced over most of southern MB
- Timing: Snow will be spreading in from the southwest late Friday, persisting through Saturday and Saturday night, then gradually pulling off Sunday. Snow expected to develop in Winnipeg Friday night (midnight or pre-dawn hours Saturday)
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| Snowfall projections (GEM model) Friday through Sunday, 5 cm ranges (yellow line is 20 cm) |
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| Snowfall projections (NAM model) Friday through Sunday, 5 cm ranges (orange line is 25 cm) |
OK, but what about what everyone wants to know: how much snow will fall in Winnipeg? Models still have been flip-flopping on that issue, but the consensus is growing that Winnipeg will see around 15 cm of snow in total from early Saturday into Sunday morning. Model estimates for Winnipeg range from a minimum of 10 cm to a high of 30 cm, but overall, they seem to converging around that 15 cm mark. It's likely however that some areas of southern MB will see more than that, perhaps 20-30 cm, including parts of the RRV and SE Manitoba (and possibly even Winnipeg if a heavier snowband hits the city)
Regardless of the total amount that falls, residents should be prepared for a period of snowy weather over southern MB beginning Friday night, lasting through Saturday, and easing off Sunday. Road conditions will deteriorate as the storm progresses, especially Saturday when the bulk of the snow is expected across southern MB. Be prepared for much slower travel times and possible road closures. Northerly winds of 30 to 50 km/h will accompany the storm with reduced visibility at times in snow and blowing snow. Improving conditions are expected Sunday as the storm pulls off. Note that this storm will also be affecting neighbouring North Dakota, NW Minnesota, and NW Ontario so keep that in mind if you have travel plans to those areas this weekend.
NAM continues to blast Winnipeg with some heavy snow with this storm.. giving us 30 cm Saturday with another 6 cm Sunday. They seem to be developing a narrow band of heavy snow across the RRV Saturday, perhaps hinting at some elevated instability that will increase snowfall amounts further west than otherwise expected. Not sure that will happen, let along over Winnipeg.. but interesting to note.
ReplyDeleteRob what does your spidy weather senses tell you? Earlier this week it seemed like the GEM was an outlier. Still looking that way?
ReplyDeleteYeah, I was thinking the GEM was too progressive and too far east earlier in the week, but the track looks to be bearing out. I think the system will be a little stronger than what the GEM was advertising earlier, so snow will be spread further west over southern MB than it was suggesting. Overall, I'm liking the 15-20 cm estimate..
ReplyDeleteSnowfall warning just issued for Winnipeg and southern MB... calling for 15-25 cm totals, locally up to 30 cm in some upslope areas.
ReplyDeleteNote That E.C. has issued A Snowfall Warning for all of Southern Manitoba incl. Winnipeg stating major snowstorm this weekend with amounts of 15 to 25 cm and possibly up to 30 cm in some areas.
ReplyDeleteKey point,however they say winds are likely not gonna be that strong with this storm which pretty much throws the prospects of a blizzard out the window at least at this time.
Hi Rob,
ReplyDeleteAre winds expected to be a factor with this storm?
And, do you think NAM is overdoing the snow amounts for Winnipeg?
Wow already issued a snowfall warning. EC must be quite convinced we will get a big storm, it's not every storm that a warning is issued this far in advance.
ReplyDeleteThank goodness this is during the weekend, and a long weekend on top of that... At least major roads would be plowed by the workweek next week.
ReplyDelete@Anonymous (the one at 4 PM):
ReplyDeleteIf you think that's crazy, you should've seen the NWS when they issued their winter storm watches.
OH MY GOODNESS! I can't believe it. John Sauder just proudly proclaimed that the storm is all unfolding just as he thought it would, and that he called it back on Monday already.
ReplyDeleteI'm guessing that his correspondence course in Broadcast Meteorology had a large section on Revisionist History.
18Z NAM now giving 35-40 CM over RRV and 18 Z GFS giving 25-30 cm over RRV which is somewhat of a departure from previous solutions(more so GFS than NAM) so more analysis certainly need before confirming/discounting these bihg snowfall amounts
ReplyDeleteRob, what are your thoughts on the 18Z NAM and 18Z GFS runs tonight?
ReplyDeleteThose higher snowfall estimates are surprising to me given the storm track, but there may be an explanation to support those higher numbers. If you look at the 700 mb charts for Saturday evening, you'll see a 700 mb low tracking right over the RRV.. which can sometimes lead to heavier bands of enhanced snowfall, especially if there's some instability aloft associated. That may explain the higher amounts noted by the NAM, and GFS. I'm just curious why the GEM doesn't seem to be catching on to that scenario. We'll have to see if the updated runs trend in that direction..
ReplyDeleteRob, are strong winds expected to be a factor with this storm?
ReplyDelete12Z GFS Q-vector diagnostics for 700 hPa shows region of strong frontogenesis only brushing us to the SE.. with main midlevel forcing over SE Manitoba, northern N Dakota and NW Minnesota. This is where banding from thermal direct circulations is most likely, along with possible CSI and slantwise convection. I would say at this point only the far SE suburbs have a greater chance of a heavier band setting up - with light snow more probable for most of the city. We'll also see how much cold, dry advection slumps south overnight - which will set up edge of precipitation..
ReplyDeleteDaniel
Winds accompanying the snowfall Saturday should be moderate strength...N to NE at 20-30 km/h with gusts to 40 or 50 at times. So while it will blow the snow around, it won't be like a full out blizzard. The poor vsbys will be mainly due to the falling snow. Winds shift into the NW on Sunday behind the system and will likely be a bit stronger as the storm pulls off.
ReplyDeleteAny chance of some thundersnow on Saturday? Will there be enough forcing/elevated instability?
ReplyDeleteHey all! I have a question regarding these models: Where do you find snowfall amounts on the model? On the A Weather Moment model viewer, most models will only display 3, 6, and 12 hr QPF, which of course only represents the amount of water in that given time frame.
ReplyDeleteRob is it alright if I use information from your latest post on my blog? I will cite the information from your blog on my post. Let Me know thx. :-)
ReplyDeleteMike..
ReplyDeleteSure thing.. if you find the information useful enough to share, by all means. Thanks for citing me as the source..
Anonymous..
Select "Accumulated QPF" to get a running total of model precipitation. Note that the amounts are in mm of melted water, which can give you a rough idea of snowfall in cm based on a 10:1 snow:water ratio. Snowfall amounts will be greater with colder temperatures, if the snow is drier, etc (eg. 15:1 snow:water ratios)
Thank's Rob, It should be up in an hour or so. See you then. Click my name to get a direct to my page.
ReplyDeleteRob, i've noticed that AB-SSK are expected to have temps drop close to -20C at night and daytime highs only in minus teens after the passage of this low...Can we expect the same kind of temps here in Southern Manitoba as well?
ReplyDeleteAnonymous. If we clear out Sunday night, it's possible we may get down to the -20C mark with a good snow cover, and highs around -10C. The good news is that it looks like any cold weather behind this system should be brief, as temperatures moderate next week.
ReplyDeleteNote..
ReplyDeleteI've mentioned this before, but keep in mind that radar imagery from EC's Weatheroffice website is still in RAIN mode, and will substantially underestimate snowfall intensities until it switches over to SNOW mode. I recommend using Brad's radar viewer (click on my name, or access from my radar page, or A Weather Moment website) and select "1.0km CAPPI" for a radar option to display SNOW rates. It will be much more representative of snowfall intensity than what WO radar is showing. You can also have longer loops, and display radar precip accumulations. (Weatheroffice radar doesn't switch to snow mode until Dec 1st, which apparently is when winter starts in Canada...)
By the way you guys can make great use of the following radar sites,
ReplyDeleteKTIV interactive radar features navigation moving place to place, storm tracks, a great view of what precip is falling rain-green, pink-mix, blue- snow. The darker the returns the heavier. Also you can overlay canadian watches and warnings and read up on the statements by right clicking on the map on the actual page. Storm tracks are included in the options tab. Great for stormtracking, I have used it for 4 years works great! Click my name for the link...
Other interactive radar sites (copy and paste)
Wundermap- http://www.wunderground.com/wundermap/
Intellicast New Beta Weather Interactive Radar Map (up to the minute radar images).
http://www.intellicast.com/Local/WxMap.aspx
Weather Network Radar Maps (Basic)
http://www.theweathernetwork.com/weather/maps/
You can increase your zoom level when on internet explorer to view the ktiv radar map in larger format. (Click My name for KTIV)
00Z NAM and GFS continue to advertise the big snow amounts. The higher amounts (30+) are gaining some traction as of late. Going to be mighty interesting.
ReplyDelete00Z GGEM has increased amounts as well, now indicating 20 cm by late Saturday (way up from their previous 10 cm). GEM has 17 cm up to 6 pm Saturday. So yes, models are definitely ramping up amounts for Winnipeg/RRV.
ReplyDeleteRob, With models ramping up the amounts for Winnipeg/RRV, do you think 30+ CM could be possible?
ReplyDeleteI'd be surprised if we got 30 cm... but models are certainly suggesting it's a possibility. So even though this thing is tracking like a Scenario 1 storm, it's giving Scenario 2 type snowfall. Normally, the heaviest snow would be not quite as far west of the track as models are suggesting with this event.. so perhaps there is some embedded instability and banding that is generating the higher amounts. Will be very interesting to see how this plays out..
ReplyDeleteSo, when is the snow expected to start it Winnipeg Area?
ReplyDelete**correction** Meant to say when is the snow expected to start in the Winnipeg area?
ReplyDeleteNote that E.C. has updated the snowfall warning which now includes the Dauphin, Arborg and Bissett areas.
ReplyDeleteThey have also adjusted the expected snowfall amounts now to 20 to 30CM with some pockets of 40CM possible.
Very interesting...the models are certainly very aggressive but becoming consistent with these higher snowfall amounts.
Wow, we are in for one whopper snowstorm...models very consistent with the 20 to 30 CM even with this morning's runs. E.C's forecast now calls for 20 to 30 CM tomorrow.
ReplyDeleteYep.. all models trending towards a 20-30 cm snowfall for Winnipeg, with the NAM suggesting storm totals of 35-40 cm possible as the storm lingers into Sunday. They show about 20 cm on the ground by Saturday evening, with another 10 cm Saturday night, and another 5-10 cm Sunday. GEM is stronger and further west on the storm now with a Scenario 2 type event shaping up, which would bring heaviest snow over RRV, and the possibility of some mixed precip (IP/ZR) over far SE MB (Sprague/Whiteshell, etc).
ReplyDeleteWill be an interesting weekend! Say good bye to that nice bare ground folks!
This will make you laugh :) click my name for link
ReplyDeleteThat is pretty funny. Have to like youtube lol
ReplyDeleteWorked by last mid shift in this stretch at NWS Grand Forks ...so off to bed soon.. but just saw some 12z GFS model data and it follows 06z GFS trend of surging warmer air at 850 mb farther north and west than prev runs did and thus as Rob mentioned I think snow totals down in southeast MB may be toned done some due to sleet issues.... freezing rain/drizzle still a good best down into Grand Forks as well but intensity of precip not heavy.
ReplyDeleteJackpot looks like Turtle Mountains north-northeast to maybe just west of Winnipeg.... I havent seen 12z GEM.
Off this weekend but will check back to see what happens.
So when's the snow going to start? Numerous models suggest after midnight. CBC says this evening. CTV says this afternoon already (according to their website).
ReplyDeleteI'll stick with the model consensus of around 1-2 AM.
Snowfall warning upgraded to winter storm warning for most of southern MB. Heaviest snow expected from SW MB through northern and western RRV into the Interlake areas.. freezing rain/ice pellets expected over far SE MB which will reduce snowfall amounts there..
ReplyDeleteLooking at the meteogram for Winnipeg, comparing all the models...Right now it has the GEM Global as an outlier with higher accumulation. Will be interesting to see if things trend that way in the end.
ReplyDeleteJust so everyone knows, the RADAR Viewer on my blog ( http://cl.ly/KnkF ) has been updated to default to the 1.0km CAPPI imagery, which is more suitable for snow. Note that if rain is falling, it will appear more intense than it actually is (1.5km CAPPI is better suited to rain).
ReplyDeleteGood stuff Brad.. I've mentioned that on my new post..
ReplyDelete