The pleasant stretch of above normal temperatures and quiet weather will be coming to end today thanks to a cold front that pushed through southern Manitoba overnight. Gusty north winds to 50 or 60 km/h behind the front will usher in much colder air from the northern Prairies, with temperatures falling through the day towards the -10C mark by evening. The gusty northerly winds will be make it feel even colder with wind chills falling to the -20 range. In addition, periods of snow will be spreading across Winnipeg and the RRV this morning, with about 5 cm possible by the drive home. This will result in deteriorating road conditions today, with occasional reduced visibilities in snow and blowing snow. Road conditions are already slippery this morning from some early morning freezing drizzle that left a coating of ice on untreated surfaces.. and a layer of wind blown snow will continue to make for slippery conditions through the day into the evening. Caution on the roads today.. winter driving skills will be required once again.
Follow snow on radar today. 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.
Guys you can also try out KTIV Interactive Radar best for storm tracking, viewing what precipitation is falling along with so much more. (Click on my Name for access)ReplyDelete
Oh and Intellicast weather active map for up to the minute radar data. Give it a try....ReplyDelete
Deformation band slumping SE as models indicated yesterday. I see that EC upped snowfall accumulations to the 5-10 cm range. All higher resolution American models push the snow band thru by 5 PM, with 3-5 cm of additional accumulations. To get 10 cm, we would need moderate to heavy snowfall rates of 2cm/hr under a mesoscale band. Right now, 1cm/hr rates are the highest on RADAR. Will have to watch RADAR trends to see if band weakens as it passes thru.. or if banding flares up, but I would say given current trends we have about 3 hours of 1 cm/hr snowfall intensities, so depending on lower water ratios 4-5 cm still looks reasonable at this point.ReplyDelete
BTW, snow-depths for many areas in central to south Winnipeg as low as 1-3 cm with lots of bare patches showing, although I see Rob still had 8 cm in Charleswood as of yesterday.
Band is weakening, with back edge near Woodlands, looks like the 2-3 cm will verify after all.ReplyDelete
Rob or Daniel,ReplyDelete
I've noticed that models continue to trend toward a strong negative AO by the end of the month. In fact the ECWF is indicating some very cold temperatures for our region later next week and beyond into December.
Does this look like we could be in for a prolonged period of well below normal temps going into December?
Daniel.. Down to 7 cm as of this morning, measured in my backyard which is more sheltered. Less snow in more open places, more like 2-5 cm.ReplyDelete
Back edge of snow on radar pushing in from the northwest.. should be into WinnIpeg over the next hour or so. So we'll be in this little burst of snow until then, and then that should be the bulk of it. Have had maybe 1-2 cm, tough to measure due to the drifting, and likely not more than 5 cm by the time it's done.
CPC outlooks indicate a greater than normal chance for below normal temperatures over central and eastern Canada over the next 6-10 days due to a -ve AO developing. How long that will persist into December, I don't know.. as I've indicated many times, I'm not much of a long range expert as I like to focus more in the short to medium range (which is challenging enough!)
Southbound lanes of perimeter Highway closed at Roblin Avenue due to MVA.ReplyDelete
Are we still expecting some more snowfall on Saturday with windy conditions?
A question was asked regarding the precip amounts from the newer AWOS's in ND (Rolla, Langdon, Walhalla, Cavalier, etc). In short the amounts are estimates and are not accurate in wind.ReplyDelete
I spoke with the company which installed them and there is no tipping bucket on them and for precipitation amounts it uses an algorithm which looks at how fast the precipitation is falling in front of a laser beam. In windy situations it will way over d
o precip, regardless of rain or snow. So you cannot trust these precip amounts from sites such as Rolla, Langdon, Cando, Walhalla, Cavalier, Grafton, Rugby and others any time there is wind. It will over do it. The FAA has requirements for these systems since they are used mostly for aviation purposes and whether it is accurate in precipitation amounts is not something the FAA cares about.
I measured about 3 cm of new snow today at my place.. Tough to measure as there was a lot of drifting, but I tried to get a representative average.ReplyDelete
As for Saturday, latest guidance is taking bulk of snow across Interlake and central Manitoba. We may get a period of light snow here in the RRV but at this point, it doesn't appear like it will be much.
What time is the wind going to let up? North side of the city the winds are howling.ReplyDelete
about an inch or two in the Grand Forks-Fargo areas with this system.ReplyDelete
Some streamers coming off L Manitoba this evening. I would estimate about 2 cm has fallen in central parts of the city. With the wind that will compact down to very little additional snow depth.ReplyDelete
A bit of gradient NW to SE across the city wrt to that snow depth.. although its swamped by variability of site exposure/aspect(less in open and more in protected locations). Its too bad the snow sensor data is so poor. Hard to get a sense of snowcover out in the open areas NW of the city. Latest reading still stuck on 11 cm. Portage has dropped to 12 cm as of yesterday.
Btw, Canadian model guidance appears far too cold for temps late Friday and early Saturday, with raw model products showing -26 to -29 C (although SCRIBE is a more reasonable at -20 C). The Canadian models are also further SW with the track of the clipper it seems. Right now, I would lean more on warmer American guidance (which shows -13 to -15 C).
There will be a quick drop later tomorrow evening with high pressure lingering overhead, but return flow gets going early Saturday. Not enough fresh snow cover to have faith in the coldest guidance. We'll see what kind of air mass we're dealing with tomorrow as the ridge moves into western Manitoba.
Daryl.. Winds will remain gusty from the NW through midnight then start gradually diminishing overnight, but still around 30 km/h. Blowing and drifting snow will be an issue this evening especially for westbound lanes of the north perimeter and southbound lanes of the west perimeter.ReplyDelete
In a previous post, you mentioned that EC will be updating its forecast pages on Weatheroffice including display of 3 hour forecast data. Curious where you heard about that because I haven't seen anything mentioned on that yet.
All guidance show non-diurnal temp trend after midnight or so, including meteocode for Winnipeg (numerical basis for text forecast). However, public forecast still makes no mention of rising temperatures.ReplyDelete
Regional models giving us 4-5 cm tomorrow (RGEM and NAM).. atypical pattern to QPF with NAM showing banding in region of warm advection. SCRIBE is lower, perhaps correcting for more typical scenarios (~3.5 cm). Meteocode from 11 am still shows 2-4 cm accounting for the range seen in raw vs SCRIBE values. I suspect it may go up more to 3-5 cm to reflect the current range. Will have to see tomorrow if that banding does set up in the warm advection zone tomorrow..
Re Garth and SpotWx,
Btw, if possible, a nice addition to the site would be the model output statistics from NAM: MET (MOS ETa) and GFS: MAV (MOS AViation) & MEX (MOS EXtended).
Daniel - I can add anything from here:ReplyDelete
But let me know if you have other sources for model data and I'll get happy add them (as able).
So far I've had requests for wave models and the DGEX, and also plan to process the NAM for the Alaska and Hawaii domains, and then the ensembles.
"...get happy add them"?ReplyDelete
"be happy to add them" is what I meant. LOL