Winter Arrives

Environment Canada made headlines with the special weather statement for Winnipeg issued Monday with a referential start: winter is coming. And how.

Today will mark the beginning of a harsh slide into winter after a essentially a month of temperatures well above seasonal for this time of year. The change in the pattern will be brought courtesy a rather peculiar weather setup that will see a relatively weak Colorado Low moving north through Minnesota into Northwestern Ontario merge together with an Alberta Clipper quickly moving eastwards across the Prairies. Each system is moderately potent in their own right, but when combined, they will form a new storm system that will rapidly intensify, driving strong northwesterly winds through the province alongside the first significant snowfall for many regions of Southern Manitoba.

Today will start deceptively. Relatively light winds and temperatures climbing towards 5 or 6°C will give a false sense of security betrayed only by the increasing cloud cover that will build in through mid-day into the afternoon. Some light rain will develop over the Red River Valley this afternoon, which will mark the end of our above-seasonal temperature streak and usher in winter. As the rain moves into the region, winds will pick up out of the northwest to around 50km/h sustained with gusts as high as 70–80km/h. The rain will switch over to snow sometime in the evening and likely begin piling up fairly quickly as the strong winds rapidly cool the ground and other surfaces.

The strong winds and snow will persist through tonight as temperatures dip down towards –3°C or so as colder air begins filtering into the region. With snow piling up and such strong winds in place over the Red River Valley, it’s quite likely that driving conditions become quite poor as roads freeze, become ice covered, and see reduced visibility in blowing snow.

AWM Snowfall Forecast issued November 18, 2015
AWM Snowfall Outlook issued November 18, 2015

Thursday will continue to bring light snow and strong winds to the region as temperatures remain around –4°C or so. The winds will be a bit lighter than at their peak, but will likely remain near the 40 gusting 60km/h mark through much of the day before beginning to taper off in the evening. Overnight, other than some lake-effect snow streaming southeastwards off of Lake Winnipeg, there’s likely to be just a few flurries lingering in the region. Temperatures will dip down to –6°C for the overnight low.

In general, around 5–10cm of snow is likely to fall with this system through southeastern Manitoba, the Red River Valley and northwestwards into Parkland Manitoba. Exact amounts will depend on the timing of the change-over from rain to snow and how quickly the snow begins accumulating instead of melting on the ground.

Friday will be a mainly cloudy day with just a very slight chance of light, scattered flurries. Temperatures will recover only a degree or two from the overnight low with highs around –4°C. There may be a few clear breaks through the Red River Valley on Friday night, but overall there will still be a fair amount of cloud as temperatures head towards an overnight low near –10 or –11°C.

Colder Weather Continues Through The Weekend

The cooler weather, which while a significant drop from what we’ve been experiencing is, in actuality, just a couple degrees below seasonal values for this time of year, will persist through the weekend.

NAEFS 8-14 Day Temperature Anomaly Outlook valid for November 25 to December 2, issued 12Z November 17, 2015
The NAEFS is showing a trend towards seasonal temperatures for the remainder of November.

Daytime highs around –5 or –6°C will be in place over Winnipeg & the Red River Valley this weekend, with a chance of some more flurries on Saturday improving to sunnier fare on Sunday. Overnight lows will be in the low minus single digits. So, while it may be a huge change from the weather we’ve been having, we’ll be shifting to more seasonal weather for the end of November.

Dreary Start to the Week

This week will start out on the dreary side as a series of low pressure systems bring rain to southern Manitoba. Some parts of southern Manitoba may even see a bit of snow by midweek.

A low pressure system will bring light rain to parts of southern Manitoba on Monday
A low pressure system will bring light rain to parts of southern Manitoba on Monday

Monday

Today will feature mainly cloudy skies and light rain showers as a low pressure system passes through southern Manitoba. Rainfall amounts in the Winnipeg region are expected to be under 2 mm, but areas further north may see slightly higher amounts. Winds will be light and temperatures will be relatively mild (near 10C), so conditions will generally be comfortable outside of the rain showers.

Tuesday

More rain appears to be on tap for Tuesday as we come under the influence of another low pressure system pushing up from the south. Like Monday, accumulations are expected to be small, with amounts of only around 2 mm expected. It will be windier and cooler than Monday though, with temperatures in the mid single digits and breezy north-east winds.

Wednesday

Wednesday will see the continuation of Tuesday’s system with more rain likely in store. Accumulations will probably range from 2-4mm in the Red River Valley. There is a chance of snow in the higher terrain of western Manitoba, but it is too early to say how much could fall. Temperatures will be in the low to mid single digits with a breezy north-west wind.

Long Range

The long range forecast continues to strongly hint at above-normal weather for the first half of November. The combination of a positive Arctic Oscillation and the increasing influence of El Nino will allow Pacific air to continue moving across the Prairies while preventing significant Arctic air masses from surging southward. That isn’t to say we won’t get cold weather this November, but it certainly seems most likely that warmer conditions will dominate. Given that the normal high for this time of year is only 3C, “warm weather” will be a relative term from this point forward.

Chilly Mid-Week, Gradual Return to Above-Normal Temperatures

Today will be off to a chilly start as rain showers or flurries move through the Red River Valley alongside near-freezing temperatures and a gusty northwesterly wind. Fortunately, this brief outbreak of colder weather will be short-lived as above-normal temperatures gradually build back into the region for the weekend.

Cool & Soggy Wednesday

It will be cool and soggy today for Winnipeg & the Red River Valley as a brisk west to northwesterly wind carries flurries & showers through the region. Much of today’s precipitation will fall as rain, however for several hours this morning snow will be possible. No significant accumulations are expected since temperatures (and the ground) will be above zero, but it could be enough to dust grassy areas and cars.

Temperatures will be below-normal today with the high temperature topping out at just 6°C.

RDPS 12hr QPF valid for 00Z Wednesday October 28, 2015
RDPS 12hr precipitation totals valid for 00Z Wednesday October 28, 2015

The wind will be out of the north to northwest for much of the day at around 30km/h with some gustiness on top of that, however as an inverted trough passes through late in the afternoon & the pressure gradient straightens out, winds will increase to 40–50km/h this evening for several hours before tapering off as a ridge of high pressure pushes in overnight. Temperatures will drop to around 2°C overnight.

Warming Trend for Second Half of the Week

Thursday and Friday will be slightly more pleasant days with temperatures gradually returning to seasonal values. Both days will see a fair amount of cloud through the Red River Valley, although Thursday has the potential for a few more sunny breaks than Friday does. Daytime highs will be just above the seasonal value of 6°C on both days with a high of 7°C expected on Thursday and a high of 9°C on Friday. No precipitation is expected on either day and overnight lows will sit near the freezing mark both Thursday & Friday nights.

Well Above-Normal Temperatures Return for the Weekend

Snow suits will be absent for Halloween this year as temperatures some 6°C above normal will result in a relatively mild end to October.

CPC 6-10 Day Temperature Outlook
The Climate Prediction Center’s 6-10 day outlook is predicting a fair chance for above-normal temperatures early next week.

Daytime highs in the low teens are expected this weekend and into the beginning of next week thanks to a broad zonal flow that will develop aloft, keeping the colder Arctic air in the north and spreading milder Pacific air across the southern Prairies.

There’s a bit of uncertainty as to precipitation; most models show a dry weekend ahead, however the GFS wants to push a disturbance through midday Saturday bringing a shot of rain to the Red River Valley. We’ll keep an eye out as that situation develops and be sure to have a complete Halloween evening forecast in our Friday forecast. Other than that, it does look like we’ll head into a more unsettled pattern next week, with potentially the first “real” snowfall of the season, so enjoy the coming mild weather while you can!

Pleasant Fall Weather Gives Way to End of Week Rain

The weather will be relatively pleasant for late October over the next couple days with above-seasonal daytime highs expected and a fair amount of sunshine. Things will take turn on Friday for the end of the week as a Colorado Low sets its sights on Southern Manitoba and brings a decent shot of rain along with it.

Today will see the cloudy skies that start the day gradually break up and become mixed to partly cloudy. Winds will pick up through the morning and make for a fairly windy afternoon with gusty northwesterlies at 40–50km/h. Today’s daytime high near 12°C will be around 4–5°C above the normal daytime highs for this time of year. Heading into the evening, the winds will taper off and skies will clear as a ridge of high pressure pushes into the province. Expect an overnight low near –2°C.

Thursday will be quite a pleasant day with relatively light winds at 20–30km/h out of the southeast and a high once again near 12–13°C. Clouds will move in overnight as we head to a low near 5–6°C.

Forecast 12hr. precipitation accumulations for Friday from the GDPS
The GDPS is forecasting 10-15mm of rain over Southern Manitoba on Friday.

Friday will see the Colorado Low push into North Dakota and Minnesota, spreading an area of rain northwards into Southern Manitoba. There’s a surprising amount of agreement in the track of the low, but how much rain it will produce seems to be a tough topic. The Canadian Global model, pictured above, shows around 10–15mm through the day on Friday, however I think it’s a bit on the low side. My best forecast at this point is that 10–20mm of rain should be expected through the Red River Valley and southern Interlake on Saturday, however for areas in the RRV south of Winnipeg, particularly closer to the U.S. border, 15–25mm seems like a possibility depending on a number of factors.

Alongside the rain, our daytime high will climb to around 9°C. Winds won’t be too much of an issue and will remain relatively light out of the southeast switching to northwest in the evening. In the evening we’ll see the last of the rain taper off and head to a low near 4°C.

Cooler air looks to push in through the weekend behind the low, so enjoy the milder temperatures today and tomorrow!