Friday, January 22, 2010
Winter Storm Warning posted for southern MB
Winter storm warnings have been posted for all of southern MB as a large storm system over the central and northern states slowly moves towards Minnesota. This system will bring a prolonged period of snow, beginning tonight and continuing through the weekend into Monday morning. The first wave of snow will be pushing into southern MB tonight from the south, and may mix with ice pellets or even freezing rain tonight into Saturday. Snow will ease somewhat over southern MB Saturday as the heaviest snowband shifts north, with precipitation possibly changing to drizzle or freezing drizzle as surface temperatures hover near the freezing mark. Snow is expected to redevelop Saturday night into Sunday as the main low pressure system intensifies over Minnesota. Northerly winds will increase later Sunday into Sunday night with snow and blowing snow giving poor visibilities and travel conditions Sunday night into Monday. All in all, storm totals of 15 to 25 cm are expected across southern MB by Monday morning, with the highest amounts across the western Red River valley through the eastern slopes of the Riding Mountains.
Posted by rob at 4:44 PM
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When temperatures hit lower than -15C, there's sunshine. However, why we don't get sunshine when temperatures rises to -10C or warmer, particularly this time of the year?ReplyDelete
NWS Grand Forks notes in its latest discussion that the NAM seems to be doing the best with precip types. This means that south-eastern Manitoba will likely see a good period of liquid precip tonight (likely rain), before things change over to snow tomorrow.ReplyDelete
I'll be sure to post an update on precip types in Steinbach when it starts 'precipitating' here (don't actually know what form of precip to expect).
Thanks Scott.. I suspect you'll be seeing ice pellets this evening as the precip moves in.. mixing with or changing to snow overnight. Aircraft soundings from Winnipeg this evening show an ice pellet profile, with near freezing air at 800 mb, and below freezing temps (down to -4C) between the surface and 800 mb. This will likely be the case for much of the RRV and SE MB tonight.ReplyDelete
I can confirm that ice pellets are falling in Steinbach. The surface temperature is above freezing, so they are melting as they sit on the ground.ReplyDelete
Update..ice pellets now mixing with rain, probably a sign that a total switch to rain may occur shortly.ReplyDelete
I am expecting the possibly for all precipitation forms over the next 24 hours. Freezing rain looks like least likely, with surface temps above zero now, but ice pellets, rain, and snow are all a certainty now that I have observed two. If the surface temperature falls below zero for a brief period of time, then I'll get all precip forms.
Update from Grand Forks...I am not at work...but at home. Varied pcpn types here...goes from rain (temp 33) to large snow flakes then to sleet.ReplyDelete
A 1/2 inch of new snow.
This is as of 1015 pm
Dan-GF, what are your models showing in terms of snowfall for south-eastern Manitoba (steinbach in particular) and Winnipeg.ReplyDelete
According to most models, I see around 15 to 20cm for Steinbach and Winnipeg. However, I noticed that the NWS was showing 20 to 30cm (8 to 12") of snow along the International border.
Scott -- it looks like the main deal will come later Sunday into Sunday night as the winds increase. For the whole event I would say 25-30 cm. NAM which started off being horrible and way south was better with its warmer temp profile tonight. It and the GFS have been very consistent in showing a strong def zone snow event Sunday into Sunday night from northeast ND into southeast MB and NW Ontario around a second developed low that will be somewhere over eastern MN.ReplyDelete
Thanks Dan. Coincidentally, the 00Z GEM also shows 20-30cm for Winnipeg and Steinbach.ReplyDelete
Straight ice pellets in Winnipeg now.. not much icing up with temperatures just slightly above freezing (+0.2C) Bright banding noted on radar over Winnipeg which corresponds to area of ice pellets. Progged soundings indicate us going to a snow profile overnight, however we may stay as ice pellets longer given temperature profile upstream in ND. Snowfall amounts will be reduced due to ice pellets.. perhaps 2 to 5 cm tonight for Winnipeg and SE MB.ReplyDelete
Light rain now, just slightly below freezing in my back yard. Temperature has been slowly climbing.ReplyDelete
What a forecasting NIGHTMARE!ReplyDelete
Snow then to ice pellets, to rain, now at 3:20 am back to snow!
Yeah, it's been a real challenge to forecast pcpn type over RRV.. just goes to show you how a degree or two can mean the difference between rain, snow, ice pellets, or frzg rain. Also goes to show you that 12 hr upper air soundings are not very helpful when the pcpn type is changing by the hour!ReplyDelete
Measured 5 cm of very heavy packy snow out there.. it's like an April snowfall instead of January. Great snowman weather but take it easy shovelling if you have heart problems.. this is a "heart attack" type of snow. Looks like we'll get a break from the snow over the next hour before another wave comes in from the south.
I've received 6.6mm according to my heated rain gauge (automatic). However, this gauge usually under records precipitation in winter, so I'll give you another update when I melt down my manual gauge...along with snowfall amounts.ReplyDelete
7 cm of snow in Charleswood.. likely 10:1 snow:water ratio or lessReplyDelete
Rob, should the precipitation stay as snow throughout the day today? Temperatures around 1°C, quite close to rain!ReplyDelete
Thanks for all the updates guys.
jewels.. I think precipitation should stay as snow. Warmer air aloft has pulled east, and it's snowing through ern ND now. Yes, the temperature is just above zero, but it just means wet snow rather than rain. We may see some light drizzle though..ReplyDelete
I've received 9.6mm of water, along with 4cm of snow and a good layer of ice pellets/rain. I wouldn't be surprised if the snow ratio is lower than 10:1.ReplyDelete
The snow is melting quite a bit here, so I wouldn't be surprised if I'd actually received closer to 5cm of snow - since I only measured after the snow had stopped for awhile.
Saturday, 09:00hrs, 7cm of snow.ReplyDelete
Sunday the winds look very strong but will have to gets some more powdery snow or the wind will have a tough time blowing around this "slop"ReplyDelete
Looks like the winter storm warning has been changed in Grand Forks!!
Looks like not as much snow down there with the bulk of it north of the border!
Hi I am working today and I updated the forecast. Issue was it mostly rained last night in Grand Forks southward (some snow and ice) but more liquid. 1 inch of slush by 12z here with 0.5 inch in Fargo. dry slot moving eastward into the rrv later today. but since update a band of snow has formed with vsbys 1/2 mile up and down the river ahd of a vort in ne sd. this threatens my downgrade to advisory. I hope not as hate to look stupid. But I believe in aggressive forecasting and hate just doing nothing if I think it deserves updating I like to do it. Sunday snow down here not as great as previously thought. Thus before this band I was thinking 2 to 5 total.ReplyDelete
will see... I see SE MB got not as much too with warm air...still think 10 to 20 cm psbl thru sun eve....better wraparound up there sunday night-monday.
tough storm to deal with.
We did get a coop report of 10 inches in Langdon but 6 inches at other sites along the border west of there.
It's because temperatures don't generally rise to -10 C or above unless warm air moves in. Warm air is usually moist as well and that leads to cloud or fog formation. The exception is Chinooks, which are warm and dry, but they are mostly felt in Alberta. By the time they get to SK/MB, they pick up some moisture.
Personally, I prefer the cloudy, 'warm' days. Sun or not, anything below -20 C is ghastly.
In Silver Heights, 3km SW of CYWG, we've received 10cm as of 1200hrs on Saturday. The snow is wet and heavy, air temp just above 0C. We've had a nice break for the last few hours, but radar shows a new band of pcpn pushing up through Steinbach. As others have mentioned, we will need some drier snows if we are going to have blsn on Sunday night and Monday.ReplyDelete
Its snowing here right now (steinbach), but the surface temp is +2C. Therefore, all snow is melting on contact. The existing snowpack is very slushy, so if anything the water content of the snow is increasing, while the depth is actually decreasing. I expect some fairly significant accumulations of water today - but very little further snowfall accumulations. So far I've received about 5cm of snow, plus another 6-7mm of rain/ice pellets/freezing rain/melted snow.ReplyDelete
I would like to call this theReplyDelete
Another 3 cm today in Charleswood.. 10 cm snow total so far. But as Scott and others noted noted, snow is melting as it's falling, and the existing snowpack is settling a bit, so there's no real increase in snowdepth. But man is it heavy! Water content of snowpack has risen considerably with this event.ReplyDelete
New snow amounts look minimal over the RRV tonight through Sunday with temperature remaining near the freezing mark through early Sunday afternoon. Then colder air sweeps in by evening with temperatures falling to minus 12 by Monday morning. This sets the stage for an interesting Monday morning commute as the cold air freezes up any wet slushy snow. This will make for slippery road conditions Monday morning. Blowing snow should be less of an issue with this heavy wet/frozen snowpack over the RRV.. however, we still could see poor visibilities in snow and blowing snow Monday if winds are accompanied by fresh drier snow.
Did the second storm fizzle out.ReplyDelete
With a low of only -0.1C today, Winnipeg airport set a new record for warmest minimum for Jan 23rd. (kind of like a record warm night as opposed to a record warm day) Previous record high minimum for today was -5.5C in 1977.ReplyDelete
As far as I know, there have been only 2 other minimum temperatures in Winnipeg since 1872 that were milder than -0.1C, namely +1.1C on Jan 12 1928, and 0.0C on Jan 14 1894. Third warmest January low in 138 years.. impressive!
Looks like the second storm is carrying snow further east, while snow on the backside will not be as heavy as first thought. This will make the second wave less intense than originally expected. However, the strong cold winds Monday will pose a problem even if there's light snow falling..
If this slush freezes up on Sunday night, then we will need some light snow on Monday morning to produce blizzard conditions. As we know from past experience, it only takes a few centimeters of snow to produce a blizzard if the wind is strong enough. I suspect that if we get 2 to 4cm on Sunday night and Monday morning, that will be enough to produce a blizzard.ReplyDelete
Still no new accumulations here. Snow is melting on contact, so it is impossible to measure. I suspect that if it was cold enough to accumulate, we would have about 10cm of new snow today.
Here are some numbers for you..ReplyDelete
Today's precipitation in Steinbach:
Snowfall (accumulated est.): 5cm
Snowfall (melted est.): 4cm
Ice pellets, rain, fzr: 4.5mm
Total QPF: 13.7mm
Water content of snowpack: 33mm
The water content of the snowpack has doubled with this storm. When I took a snow core last week, the water content was around 16mm. More snowfall tomorrow will likely mean the water content will approach 40mm.
Perhaps most interesting of all is the model performance. Yesterday's 18Z NAM predicted 13.69mm of QPF for Steinabch today. The actual QPF was 13.7mm! Amazing model accuracy from the NAM. So based on that accuracy level, what was the 18Z NAM predicting for the rest of the weekend?
According to the 18Z run, Steinbach can expect another 12mm of QPF tomorrow afternoon into Monday morning. This should equate to 10 to 15cm of snow. Since the NAM indicates colder temperatures moving in at this time, I would expect most of that snowfall to stick.
My apologies, I meant to say the 18Z GFS in my last post. The NAM wasn't quite that accurate.ReplyDelete
Models finally starting to better resolve evolution of this complex system. I just never bought into placement/strength of deformation zone on GFS given the surface pressure pattern it was generating (Missouri/Illinois low). Model as often seems to happens in these cases struggled with the transfer and consolidation of energy to southern system.ReplyDelete
With SE flow continuing for some time and evaporative cooling effects abating.. I wouldn't be surprised if we actually reach our high temp this evening. Wet snow acts much like rain in that liquid water percolates thru the snowpack beneath efficiently distributing heat and causing rapid melting. Mist and fog condensing on the snow release latent heat which further increases temp/melting of snowpack. Depending on when we eventually drop below freezing, we could be looking at less snow than when we started.
Attention then turns to the true Colorado low which looks to track up thru Illinois and Wisconsin. Very impressive LLJ/warm air advection tonite over lower Midwest and Ohio Valley. Precip surges north into NW Ontario by midday tomorrow and deformation zone will try to back into Manitoba.. question is how far west will it get. Will have to see model trends on track of low on next runs.
This low will be absorbed by arctic vortex which drops straight
south out of Baffin Island heralding the transition to a much colder pattern like Rob had mentioned earlier.
NAM shows deformation zone setting up in eastern Manitoba on Monday, bringing an additional 10cm to the region. It shows an additional 5 to 10cm for Winnipeg on Monday. Will need to watch 00Z GFS to see if this is confirmed.ReplyDelete
If you read Environment Canada's warning they state that Sunday night into Monday could have very low visibility in snow and blowing snow
INCLUDING THE CITY OF WINNIPEG!!
You agree that conditions could be that bad in the city???
We'd have to get fresh snow Sunday night and Monday to get poor visibilities in the city. Without new fluffy snow, there won't be any blowing snow in the RRV due to the wet snowpack we have now (which will freeze up by Monday morning)
So the question becomes.. will we see new snow Sunday night and Monday? As Daniel and Scott have alluded to, it all depends on how far west the wrap-around snow from the Wisconsin storm gets to us. Right now, model consensus is that the bulk of the new snow will be east of Winnipeg and the RRV, with poor vsbys in snow and blowing snow mainly east of the city. If that area of snow edges further west, then it could be pretty bad for the RRV. With a track moving towards Thunder Bay, my bet would be most of the new snow will stay east of Winnipeg..
I can chime in on the warning (for reasons I won't mention but I bet you can guess). Heehee.ReplyDelete
The north perimeter was mentioned specifically because it looks like there's going to be about 2 to 4 cm of new snow in the cooler air in the wraparound, and that will be followed by north winds of 50g70 throughout the valley, per latest guidance. Winnipeg, being a large city, will be for the most part spared blizzard conditions, but anyplace in the city (such as the north perimeter) that's exposed to a long fetch of nothingness (relatively speaking) to its north could see blizzard conditions. I wouldn't be surprised to see the RRV planted in a blizzard warning by this time tomorrow.
And just a clarification, QPF = quantitative precipitation forecast. If you're talking about amounts that have already fallen, you're talking about QPE (quantitative precipitation estimates), if anything with an acronym.
Picked up another 3 cm last night in Charleswood, along with some drizzle. Storm total 13 cm so far, although actual snowdepth is only about 10 cm due to melting and compaction. Reminds me of snowstorms from my southern Ontario days.ReplyDelete
Large dry slot has effectively ended precipitation for us for today. Now we wait for the cold air and any wrap around snow tonight into Monday. As noted, blowing snow and visibility issues will be contingent on receiving new dry fluffy snow. Best chance of new snow is overnight through Monday morning with a couple cm possible in Winnipeg/RRV which would make for difficult travel conditions for the morning commute..
Looks like the cold air will be back with us for a while....as pattern shifts back to large upper low over hudson bay region and cold highs dropping southeast from NW canada. Not extreme cold by any means but no more of this slop...which to me is a good thing.ReplyDelete
Checking the radar just minutes agoReplyDelete
I noticed that an area of snow has just formed out of nowhere!!
Maybe we will get some more snow today!
Blizzard conditions have formed in areas like Regina!
With a little falling snow and the winds are 70 km/h visibility is down to 0.6 km!
That would indicate that Winnipeg and RRV could be in the same boat tomorrow ASSUMING that we get that falling snow at the time of the strong winds!
FYI liquid equiv pcpn amounts in the RRV were mostly int he 0.75 to 1.20 inch range...with heaveist liquid amounts around Fargo. Snow depths mostly range around 15 inches...but range from 10 to 19 inches.ReplyDelete
We are already preparing our Flood fight 2010 shirts the southern red river basin looks to be under the gun the worst.
Its 10:30am on Sunday and the cold air is beginning to move in. The temp has dropped 1.2C in the last 20 minutes and the winds are just starting to pick up. Now would be a good time to get the slush out of the driveway...before it becomes a block of ice. Tomorrow looks interesting; I walk to work (due north). Tomorrow morning could be a rather grim tromp to the School of Met.ReplyDelete
Still hasn't started dropping here in St-Vital though, my thermometer still indicates +1°C currently. Some snow grains/drizzle coming down.ReplyDelete
Yep, the cooldown is starting.. temperatures are already down to -4C just northwest of Winnipeg so our temperature will continue to drop below freezing through the afternoon into the evening. Things will be icing up as all that standing water and slush start to freeze over, especially by evening as the wind starts picking up. Careful on the roads, especially outside the city..ReplyDelete
Blizzard warning issued for all of the Manitoba Lakes!ReplyDelete
Missing all your fun...down south and its hot.Came in to catch the Vikes GameReplyDelete
Dan GF is that a record to date for pcpn GFks and Fgo
Missing all your fun...down south and its hot.Came in to catch the Vikes GameReplyDelete
Dan GF is that a record to date for pcpn GFks and Fgo
Lucky you.. go Vikes!ReplyDelete
to the person who asked about GF and Fargo precip I will have to get back to you on that....not sureReplyDelete