 |
GEM prog valid noon Sat Nov 24th
showing band of snow moving
across southern MB |
A low pressure system over southern Alberta will be tracking into southern Manitoba Saturday bringing a band of snow ahead of it. This band of snow is expected to spread into western MB overnight reaching the Interlake and RRV areas Saturday morning. The snow will push east towards the Ontario border by late afternoon with about 2-5 cm possible as the area of snow moves through. The heaviest amounts are expected mainly north and east of Winnipeg. Note that the snow will also be accompanied by brisk southerly winds gusting to 50 or 60 km/h in Winnipeg and the RRV, which will give occasional blowing and drifting snow and locally poor visibilities at times. (eastbound lanes of west-east highways will be most prone to drifting snow Saturday) Caution is advised if travelling Saturday, particularly in areas near and outside the Winnipeg perimeter.
NOTE: Woodlands radar is currently not updating. Keep in mind that radar images from the
Weatheroffice website are still on RAIN rate and will underplay snow intensities. Consult
Brads's radar viewer from
A Weather Moment for radar showing more accurate SNOW rate intensities. For latest road and highway conditions, see
Manitoba highways website.
Looks like some issues with Woodlands radar.. no updated images on the web since 8 pm (0200z). Foxwarren radar also looks like its having some issues with the incoming snow intensities..
ReplyDeleteAntenna at Woodlands radar is broken. Technician will be on site today to repair, but images from XWL will be N/A until then.
ReplyDeleteThat sucks but what can you do things break. Rob are you still expecting about 2cm this morning?
ReplyDeleteDaryl..
ReplyDeleteYes, band of snow is approaching us from the west, but so far, snow has been light over Brandon and Dauphin areas. Snow is heavier up towards The Pas and northern interlake. Without radar, it's tough to say if this band is intensifying as it heads towards Winnipeg, but right now, it looks like about 2-3 cm from mid morning through early pm.
Sorry Daniel. I was brain dead yesterday. Yes, MOS products, from here:
ReplyDeletehttp://www.nws.noaa.gov/mdl/synop/products.php
Yes, I can work on that sometime this winter.
My plan has been to attempt a crude version of regression analysis for every METAR site around the world, using whatever models are available for that site and the observation data from MADIS. The idea would be to use the stats to identify the best performing models for the past hours/days/weeks, and also attempt some calibration for the site.
However reading up on MOS first certainly would help. Here's a good page for newbies like myself:
www.nws.noaa.gov/tdl/synop/presentations/SRMOSTalk200509.ppt
Garth
I think we had more than 2cm.
ReplyDeleteya it's turning out to be a decent storm after all. Snow has been very heavy the past 45min. Decent blowing. Wish we had radar!
ReplyDeleteEC just changed their 1200 noon forecast with a 1230 forecast saying now 2-4cm and ending this afternoon as opposed to early this afternoon. Sure would be nice if that radar would come back on line
ReplyDeleteyeah, I agree, snowing at a very good clip right now here in Windsor Park and has been pretty much through the day so far. We may get 5CM or so before it tapers off.
ReplyDeleteSnow should be tapering off soon here in Winnipeg.. webcam out of Sanford shows snow has pretty much stopped and visibility is good. A little heavier burst this past hour gave us a little more than the 2-3 cm earlier predicted.. Maybe closer to 5 cm as others have noted.
ReplyDeleteIt's been snowing pretty steady for at least 3 hours here in Oakbank, currently ~1/2 SM Moderate Snow. Sure wish they would get that radar back online!
ReplyDeleteDan Page
Retired YWG FSS
Yeah Garth, that was the site I was thinking of. That's a nice presentation from NWS.
ReplyDeleteBtw, the acronyms for the MOS reveal some of the model's past 'ancestry'. Eta was the model driving NAM before it was replaced by WRF. The GFS was essentially a merger of the higher resolution Aviation model, with the old MRF (Mid-Range Forecasting model)and its global domain. Interesting to see that MOS from the Nested Grid Model (NGM) was still available until 2009, the model itself had not been updated for almost a decade prior to that as I understand.
Daniel
4 cm of new snow at my site in Southwest Winnipeg. About 10 cm of snow on the ground
ReplyDeleteRob,
ReplyDeleteI've noticed that forecasts all calling for - 25C tomorrow night.
Do you think that the temps will actually drop that low overnight Sunday into Monday?
Must be something major wrong with the radar its still broken.
ReplyDeleteAnother 2 cm of very fluffy snow overnight at my place. 12 cm snow on ground.
ReplyDeleteWeather office says -29 tonight. Weather network says -22. I'm going for -24. Anyone else want to take a guess?
ReplyDeleteAny word as to when radar will work again
ReplyDeleteHaven't heard anything more on status of Woodlands radar.. hopefully it's fixed soon.
ReplyDeleteWow. GEM-REG still showing -32 tonight, NAM is -19, and GFS is only -15 C. A 17 C difference in the short-range!
ReplyDeleteRe: Tonight's low
ReplyDeleteI was shocked at that -29C forecast for Winnipeg.. yikes! With clearing skies and a fresh snowpack, I guess it's possible especially with a light NW flow at YWG airport, but it seems a bit extreme. I'm thinking more like -25C for much of the city, -18C downtown.
Hi Rob,
ReplyDeleteI've noticed indications of snow on Thursday and it's also in the forecast.
Does that look like a potential storm or just another quick moving clipper?
GEM (EC) still gives a brutal -29°C tonight, while NAM -18°C and GFS a relatively balmy -16°C... Goodness, terrible to have a 13 degree difference for a forecast this close.
ReplyDeleteThe American guidance is often too warm over southern MB and doesn't catch the sharp low level cooling that can occur here. RAP on the other hand is picking up on the cold low level temperatures and is forecasting -26C for Winnipeg by Monday morning.
ReplyDeleteAs for Thurday's snow.. GLB is most aggressive on that clipper system, other models don't have much. GFS and Euro hint at a slightly stronger clipper affecting southern MB by next Saturday.
It's kind of interesting when there's such a huge difference between the models, as you can tell where different forecast offices get their source data. CTV Winnipeg is calling for -25 as a low, while CBC only has -14 as the lowest temp on Monday.
ReplyDeleteYWG already showing its cold bias with temps down to -17 C already. 925 temps are progged at around -16 C for tomorrow morning.. so we'll see how strong an inversion can set up. However, snow cover is still not all that deep in open areas. Other wild card which may save us is an area of higher clouds over central Saskatchewan that are progged to drop SE over us by around 4 am.
ReplyDeleteDaniel
Click on my name for 8 pm Winnipeg temperature roundup. YWG airport at -21C is a good 3 - 7c colder than everywhere else in the city.
ReplyDeleteYeah, not only that.. its 3-5 degrees colder than most other ag-wx and CWB stations in the RRV outside the perimeter - except for Dugald, which another frost-pocket.
ReplyDeleteClearly there is an issue with cold-air damming under a NW flow at that site, or something is wrong with the sensor location perhaps.. needs to be corrected.
Daniel
Both my thermometers show -13°C right now.. -29°C seems like a long shot at this point.
ReplyDeleteAt perimeter/McPhillips area temp is currently -19c
ReplyDeleteMy thermometers here in Windsor Park at 10 PM, both show - 15.9C. Robs obs is at -16.6C and most areas in inside the city are generally between - 14C and -17C at this hour. I see the YWG sight seems to have stalled at -21C earlier and now slightly rising at -19C. With partly cloudy conditions i'd say it's not very likely we'll drop to - 29C even at YWG airport tonight.
ReplyDeleteI see YWG Airport is back at -21C at 11PM. Both my thermometers are reading -17.5C at 11PM here in Windsor Park. Regardless, definately a very chilly night tonight. Bundle up for sure.
ReplyDeleteYWG Airport at -22C at Midnight. Robs obs at -18.8C at Midnight. Both my thermometers here in Windsor Park are at - 17.9C at Midnight. Generally temps across the city are coming slightly more in line with YWG Airport now...regardless, still think -29C is a stretch tonight...it's looks more like a -25C at YWG and around -20C or -21C downtown and other sites across the city.
ReplyDelete8AM temp in CYTH (Thompson) this morning, -37 !! Ouch!
ReplyDeleteHey Rob,
ReplyDeleteAny thought on the snow this week?
Seems like snow everyday.
thanks
I would be very cautious about assuming the YWG temperature has a problem, using non-ventilated Vantago Pro's located in people's back yards (and on top of buildings) as the baseline.
ReplyDeleteI'm quite sure a sling psychrometer would have agreed with the YWG temperature, and the site is one of a handful to meet true WMO standards in the area. A few trees, buildings, concrete, the mounting height, etc. makes a huge difference in certain scenarios.
Anyone know when that radar is coming back on line?
ReplyDeleteAnonymous.. I think the issue is the siting of the temperature sensor at YWG, rather than the sensor accuracy itself. For whatever reason, a light NW flow at YWG under clear skies and a snowpack will often result in temperatures a good 3-5C colder than surrounding sites, even rural sites nearby. I'm sure that it actually is that cold where YWG sensors are located, but it's not very representative for the city or the general surrounding area in those situations. In other words, under a light NW flow, YWG has an anomalous cold bias compared to most other nearby locations. That seems to be the main issue that people have with the YWG site location.
ReplyDeleteDaryl.. Still haven't heard anything. If I hear something, I'll let you know. But it must be a more serious issue considering how long it's been down.
ReplyDeleteThanks Rob Forecasting seems to have really suffered especially over the weekend with all of the last minute updates of snow continuing or last minute expect snow. Strange we have no back up system when that radar serves over a million people and many decisons both personal and financial are made with forecasting services.
ReplyDeleteI don't see anything wrong with last night's temperatures. Here's the WeatherFarm map of the overnight lows (or click my name):
ReplyDeletehttp://imgur.com/KDotv
There was a light NW flow. Dominant low temps NW of the city were -23 to -24 C, from stations which are somewhat sheltered and aren't ventilated so don't respond as well to quick temperature changes. So in reality the temp was likely a little cooler.
Stations within NW Winnipeg were -21 to -23C, again somewhat sheltered and possibly affected also by a Winnipeg heat bubble.
YWG was -25C, out in the open, proper exposure and height, ventilated, you'd expect it to be a little cooler than the others on a night like last night.
SE Winnipeg was -19 to -20 C. Again, sheltered stations (and some non-standard heights), plus the NW wind passing over the warmer city before reaching the stations. Makes sense in my opinion.
Rob,
ReplyDeletei've noticed models are hinting at perhaps a more active storm track in Southern Manitoba later this week and into next week.
Any potential for significant snowfall events in the next 10 days or so?
The odd tree and building also provides enough friction and turbulence to create mixing within that very shallow inversion, raising temps a bit. The lack of trees NW of the airport gives a more laminar flow and allows the inversion to persist, giving cooler temps.
ReplyDeleteNeither temperature is 'wrong'. It's just a question of do you forecast for a non-standard location (ie. your yard) or the airport.
Hi,
ReplyDeleteWondering if the KTIV radar is not working correctly? Last couple days every time it is snowing the radar shows the snow is no where near Winnipeg. Same with the weather network radar.
thanks.
Wow...snowing at pretty good clip right now. gonna be that kind of winter...at least it seems that way right now. snowing everyday lately.
ReplyDeleteThe Woodlands radar is down.
ReplyDeletehttp://www.weatheroffice.gc.ca/radar/index_e.html?id=XWL
Those other sources don't have a notice, so it looks like no precip.
Those radar sites use Woodlands radar to display precipitation echoes over Winnipeg/RRV. No Woodlands, no radar data.
ReplyDeleteIssue still seems to be the radar antenna which is a bigger fix than I thought it was going to be. Still no estimate on when it will be back up.
re: Snow chances over next week or so
ReplyDeleteWe'll be in fairly zonal pattern over the the next week or so, with clippers coming through every few days. After today's weak system (about 1-2 cm), we'll clear out for a couple days then a couple waves will give us more snow between Thursday and Saturday, each capable of about 5 cm or so. Looks like another chance of snow by middle of next week.
As of yesterday, I've recorded 34 cm of snow this month, normal is 21 cm. (mind you, 22 cm of that came in that one storm of Nov 10th)
Hi Rob,
ReplyDeleteJust heard that XWL radar will be getting the necessary parts from Downsview this afternoon negating any chance of it being back in working order today. The hope is to have it up and running by 18z Tuesday.
EED
Thanks for the update EED!
ReplyDeleteYou're more than welcome! Keep up the great blogging Rob!
ReplyDeleteEED
Rob,
ReplyDeleteThe weather network is favoring a colder and snowier winter for us this coming winter, which it sure seems that way right now. It's not the only agency that has said that either. even the very reliable ECMWF is indicating this.
If you had to venture a wild guess on this, based on model guidance and latest indications would you agree with the colder and snowier winter idea?
Another 2 cm of light fluffy snow today in southwest Winnipeg.
ReplyDeleteAnonymous..
ReplyDeleteIf I had to venture a guess, I'd say it's a pretty safe bet we'll be colder and snowier this winter than last winter. Certainly it's starting out that way ( last winter, we didn't hit our first -25c until Jan 13th!) But I've given up trying to forecast what winters (or any seasons) will be like. Too many variables that will influence the outcome, some of which we don't even know how they'll play out yet. So I'll just say that TWNs forecast seems reasonable, but given the lack of any strong climatic signals, I would say there is limited predictability this winter beyond 2-3 weeks.
CBC
ReplyDeleteWeather Journal for November 26th
Light winds overnight made for a big difference in the low temperature between downtown and at the airport. Low at the airport: -25.... at The Forks: -19. Cold air is heavy and will sink into lower areas when there isn't much wind to 'mix things up'.
------------
What does this mean? The Forks is lower than the airport, and has lighter winds. So that logic should imply that The Forks should have been colder, right?
Anon - The theory is correct that cold air pools into low areas at night during light winds. However you have every right to be confused as it doesn't apply to last night's temperature difference between the airport and The Forks.
ReplyDeleteA couple of things I'd like to say..
ReplyDeleteFirst, GEM guidance was again too cold with the calm, clear conditions (~-31). SCRIBE corrected a few degrees warmer, but not enough. My speculation would be that it is overestimating snow cover (given the poor quality of snow data except for Rob's measurements, I wouldn't be surprised).. NAM also had a better handle on the high level moisture which moved between 4-5 am. Until we get a deeper snow pack, or colder air-masses - I would expect the cold bias in GEM guidance to continue.
Regarding the YWG station..
While the Manitoba Ag and CWB stations may not be up to WMO standards wrt to all parameters - I doubt these rural sites have the stations mounted on buildings, and it seems unlikely that many of them are in backyards as anonymous suggested. Again, we have all heard of automated weather stations that are inappropriately situated (too close to buildings, trees etc).. but is there specific evidence regarding these sites? (I have not visited them).
I also do not have blind faith that the station at YWG meets all requirements and specifications - particularly in light of the problems with the snow sensor and precipitation readings (seemingly underestimating amounts by 10-20%). Garth noted YWG has 'proper exposure and height'.. have you been out there (or anyone else) to confirm this recently? I understand only NAVCanada has access to that site now.
Looking at overnite lows, as Garth mentioned YWG was still coldest compared to adjacent sites -25 vs a range of -21 to -24 (throwing out the -18 C). I doubt those sites in the far NW of the city are influenced by urban heating at all. Taking a broader look: Balmoral, Narcisse, Woodlands, Inwood, Stonewall, Rosser all came in between -21 to -23 C in southern Interlake. While readings in the western and southern RRV were warmer in the -19 to -22 C range.
The bottom line is that there is a cold air drainage effect off of the higher land to the NW of the city (separating the Red River and L Manitoba watersheds). The movement of that cold, dense air is seemingly impeded by the higher friction of the city landscape to the SE (buildings, trees etc).. so it tends to get dammed or bottled up on the NW flank of the city. The sensor at YWG is very adept at picking up on this effect. It should be moved to an area that is more representative of the city and the other surrounding areas.
Daniel
Lynn Lake recorded -40.7C last night... all-time November low!!!
ReplyDeletePrevious record was -37.7C on Nov 29, 1985
Thanks Daniel. Good points. Yes, I am assuming many of the rural stations are sheltered, some even mounted on top of roofs, because I've seen examples. Even the promotional literature from WeatherFarm/EarthNetworks has a station mounted on a metal roof right on the brochure cover.
ReplyDeleteOh, here's the photo in this article:
http://www.manitobacooperator.ca/news/weather-station-network-to-double-in-three-years/1000704984/
It's mounted on a metal roof, within a sheltered yard setting. Note the large tree just beside the building, well above the anemometer height. Lawyers would have a hay-day disputing nearly any data coming from this station. Even the rainfall is questionable because it has a tipping bucket mounted on a pole causing premature tipping with the slightest wobble (I've seen an example which routinely reported 2x the rain of a proper nearby station).
The MB Ag network is much better however, as are some others.
By the way, my comments above are my personal opinion, not necessarily those of my employer. ;)
ReplyDeleteQuick radar update: Technician has arrived at XWL radar site (at 17:30z) and is hopeful to have the radar back later this afternoon.
ReplyDeleteEED
I hate to be a bother, is it possible to see the woodlands radar site from off of highway 6? Or is it down a dirt road? I am curious and would like to look it up on google earth, could you let me know thank's.
ReplyDeleteThanks EED.. looks like we won't need Woodlands for a couple days before the next batch arrives later Thursday.
ReplyDeleteCuriously, snow chances were removed from the Thursday and Friday forecasts for Winnipeg, even through GLB model indicates potential for some snow over the city. Looks like first wave comes through later Thursday into Thursday night with 2-3 cm possible, then another wave Friday night into Saturday with another 2-5 cm possible. Models having timing issues with these fast moving clippers in strong flow aloft so suffice to say we'll be in a snow threat from later Thursday into the weekend.
@Garth and Anonymous (at 4:24 PM):
ReplyDeleteDon't forget that the urban heat island effect factors in too with the temp. differences between YWG and The Forks.