Tag: Windy

Cold, Windy, and Snowy Friday the Gateway To Seasonal Temperatures

Brad Leave a comment

Today will be downright unpleasant out there as a potentially record breaking cold start to the day1 gives way to strong southerly winds as snow moves into the region. After today, though, conditions improve substantially with the record-breaking cold moving out of the area and a gradual return to seasonal weather.

The wind will be out in full force today as strong southerlies strengthen to 40 gusting 60 km/h this morning, which combined with the cold temperatures will produce wind chill values near -30 in the first half of the morning. Temperatures will slowly climb through the day, reaching -9°C this afternoon and then sticking there until rising further overnight to around the -5°C mark by Saturday morning. The winds will begin to taper off in the evening, diminishing to calm by Saturday morning.

RDPS Forecast 10m Winds valid 21Z Friday November 10, 2017
Strong southerly winds will be in place across the Red River Valley this afternoon

Those strong winds are due to the tight pressure gradient between a departing high pressure system that brought the cold temperatures and an approaching low pressure system. In addition to the winds, this low will spread light snow through western Manitoba this morning then into the Red River Valley for the afternoon. Most of the snow will be done by evening, but flurries will likely persist overnight.

While snowfall amounts won’t be too high — generally around 3 to 5 cm is expected — as the snow combines with the strong winds, travel may be impacted by scattered pockets of blowing snow. Certainly not a blizzard by any stretch of the imagination, but be prepared to take some sections of highways slowly as reduced visibility may be an issue from time to time.

RDPS Forecast 24hr. Snowfall valid 15Z Saturday November 11, 2017
General snowfall amounts of 2 to 5 cm are expected by Saturday morning across southern Manitoba

The weekend looks better; any remaining flurries should taper off Saturday morning as a very broad ridge of high pressure builds into the Prairies, although a few scattered flurries will be possible through the remainder of the day. Saturday should see closer-to-seasonal temperatures with highs near -2 or -3°C and northwesterly winds of 10 to 20 km/h under mostly cloudy skies, although some afternoon sunny breaks are possible.

Temperatures cool off a bit Saturday night into Sunday as the ridge of high pressure moves through Manitoba. Winnipeg should see a low near -10°C on Saturday night with variable cloudiness and light winds. Sunday will bring mixed skies and slightly cooler temperatures once again with highs near -6°C. Sunday night’s low is a bit of a tricky proposition as temperatures will likely dive in the evening, but then clouds and increasing winds will move in and bring the temperature back up to -6 or -5°C by Monday morning. At this point, it seems like the low will dip to around -11°C before climbing back up, but if it stays clear for a bit longer it could be a few degrees lower, or if it remains cloudier temperatures may not even dip much from the daytime high.

Long Range Outlook

Next week will bring seasonal temperatures back to the region with highs of 0 to +2°C expected on both Monday and Tuesday. A low pressure system moving through on Tuesday may bring some precipitation to the region, then temperatures cool down on Wednesday before returning to the freezing mark on Thursday as another low pressure system moves through bringing a chance of snow to the Red River Valley. So a bit of a mixed bag, but certainly warmer than it has been!

Winnipeg’s seasonal daytime high is currently 0°C while the seasonal overnight low is -8°C.

  1. This post is being written on Thursday evening; while we’re pretty proud of our forecasts, even we can’t claim to be able to forecast down to tenths of degrees! ↩

Flurries Usher in Arctic Chill, Seasonal Temperatures Return for the Weekend

Brad Leave a comment

A few flurries today will mark the arrival of another shot of colder temperatures as an approaching upper-level trough keeps Arctic air entrenched over the region. Improvement is on the horizon, with near-seasonal temperatures moving back into the region on the weekend.

Today will bring cloudy skies and flurries to much of the Red River Valley as colder Arctic air slumps southwards in the wake of a cold front that moved through on Tuesday evening. The flurries will be relatively light with little accumulations, however a light northerly flow and very cool temperatures aloft will support some lake-effect snow off of Lake Manitoba and Lake Winnipeg through the day and into the evening.

During the day, the snow from Lake Manitoba will primarily affect regions south of the lake between Oakville and Austin, including Portage la Prairie. Heading into the evening, winds shift more to the west-northwest, and while the snow will weaken with less favourable fetch, it’s likely that light snow coming off the lake will shift eastwards towards Winnipeg.

Lake Winnipeg will primarily see moderate flurries off the North Basin moving through the Narrows and adjacent areas and eastwards into Berens River for much of the next 24 hours. The South Basin will produce some lighter snow that will spread southwards off the lake, shifting southeast towards Pinawa and then eastwards towards Bisset as winds swing around in the evening.

RDPS Forecast 24hr. QPF valid 12Z Thursday November 9, 2017
Flurries are expected across much of southern Manitoba, with enhanced snow in the lee of the lakes

The widespread snow will exit the province by late Wednesday afternoon with lake-effect flurries from Lake Manitoba and the south basin of Lake Winnipeg persisting into Thursday morning.

Temperatures will climb to a high near -8°C with light northwesterly winds. Winnipeg will see a continued chance of flurries on Thursday night with a low near -18°C.1

Thursday will be a very cool day with high temperatures across the Red River Valley climbing to just-10 or -9°C. Winds will remain light with the only clouds in the region those that move off of the lakes. Skies should be clear heading into Thursday night with temperatures plummeting to a low near -20°C.2 Cloud will begin to move into the region late Thursday night/early Friday morning ahead of a warm front approaching the region.

GDPS Forecast 24hr. Snowfall at 10:1 SLR valid 12Z Saturday November 11, 2017
Accumulating snow is expected across portions of southern Manitoba on Friday

Friday will bring a weather system that will trigger a change in the large-scale weather pattern, shunting the cold air out of the region and sending Winnipeg back towards seasonal temperatures. Expect cloudy skies with light snow building into the region as the warm front moves through. Temperatures will climb to a high near -6°C, but breezy southerly winds strengthening to 40 gusting 60 km/h will make it feel much cooler as wind chill values dip to around -15. Friday night will continue cloudy with a slight chance of light snow as temperatures remain steady around -6°C. Winds will gradually taper off by Saturday morning.

Long Range Outlook

Heading into the weekend, it looks like Winnipeg will move into a variably cloudy and dry pattern, with temperatures returning towards seasonal values. Saturday and Sunday both look to bring highs in the -2 to -4°C range, then highs are expected to climb to the freezing mark for the start of next week. Overnight lows will be follow suit, climbing back into the -8 to -4°C range.

Winnipeg’s seasonal daytime high is currently +1°C while the seasonal overnight low is -7°C.

  1. Further to the south in the Red River Valley, away from the lakes, temperatures could drop into the -20 to -22°C range overnight. ↩
  2. Again, overnight lows could drop even colder further south of Winnipeg in the Red River Valley, into the -22 to -25°C range. ↩

Cooler Weather With More Snow

Brad Leave a comment

Plenty of cloud and snow is in the forecast as one low pressure system leaves only to be quickly replaced by another mid-week. Temperatures will also remain cool as a large upper trough keeps the jet stream south and allows cooler Arctic air to spill into the Prairies.

Today will bring mainly cloudy skies to the region as a low pressure system that tracked through the region on Sunday pushes off into eastern Ontario. To start off the morning, widespread flurries in place across the region will taper off as a strong northerly wind of 40-50 km/h develops. Snow will taper off by midday for many locations except for two: those in the lee of Lake Manitoba and Lake Winnipeg.

RDPS 24hr. Accumulated Snowfall in Inches at 10:1 SLR valid 00Z Tuesday October 31, 2017
At a 10:1 snow-to-liquid water ratio, which may be low for the snow coming off the lakes, models suggest close to 10 cm of snow in the lee of Lake Winnipeg and Lake Manitoba

Strong northerly winds align along the basins of each lake this morning and persist all day, and as the colder air moves into the region, bands of lake-effect snow will develop and move southwards off the lake. The areas highlighted in the area above are the most likely to see snow and significant accumulating snow. Snowfall accumulations can be difficult to forecast in these events, but indications are that as much as 10 to 20 cm may fall by the end of the day under the heaviest band of snow. The Lake Manitoba event will taper off in the early evening as a ridge of high pressure moves in and eases the winds, while Lake Winnipeg will persist longer, weakening in the evening and ending overnight.

Aside from the snow, it will be a cool day whose high near -1°C will feel closer to -8 or -9°C with the strong northerly wind. Once the ridge moves into the area in the evening, winds will taper off and temperatures will head towards a low near -8°C under mixed skies.

Tuesday will bring benign weather to the region with mixed skies and temperatures climbing back to a high near -1°C. Winds will pick up out of the south through the morning hours, strengthening to 25 to 35 km/h for the afternoon hours. By evening, more cloud will be spreading across southern Manitoba in advance of the next low pressure system as it tracks across Saskatchewan. The cloud will keep temperatures a bit warmer overnight with lows of around -3°C. Winds will continue out of the southeast at around 20 to 30 km/h.

Wednesday will see the low and its associated area of snow move through the province. In the Red River Valley, snow will begin early in the morning and persist into the evening. As is the case with these early season events, the biggest challenge with this system will be the near-zero temperatures with daytime highs climbing to around 0 or +1°C and how that will affect how much snow accumulates versus melts. The expected snowfall is around 4 to 8 cm, but the actual accumulated amount will be less than that, with roadways likely ending up with a slushy centimetre or two by the end of the day, and grassy areas seeing closer to, but not the full, amount that falls.

Fortunately, winds will taper off in the morning, so visibilities will be as good as they can be with the snow falling. The wind will pick up out of the north in the afternoon into the 20 to 30 km/h range. The cloud cover will likely remain through the night with the potential for a bit of lake-enhanced/effect snow coming off of Lake Manitoba and Winnipeg. Temperatures will dip to a low near -6°C.

The only real uncertainty with this system is how far south it will end up going, and whether or not it will end up too far south to impact our region. The general consensus is that Winnipeg and the Red River Valley will see snow, but we’ll be keeping an eye on how it develops just in case.

Long Range

The remainder of the week doesn’t look much better; Thursday will see any remaining flurries taper off with a continued north wind that makes the high near -1°C feel rather cool. Temperatures will then dip down to the low minus single digits on Thursday night and rebound to just -2 or -3°C on Friday under mostly cloudy skies. Another cold night on Friday night will lead into highs returning to the freezing mark on the weekend, but that’s due to the approach of a mother system that will bring another wintery mix to the region late Saturday into Sunday.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid November 6-13, 2017
NAEFS 8-14 Day Temperature Anomaly Forecast — Valid November 6-13, 2017

Once that passes by, a significant chill will descend across the Prairies, bringing below-normal temperatures for an extended period, alongside the potential for more snowy weather.

Winnipeg’s seasonal daytime high is currently 4°C while the seasonal overnight low is -5°C.

Fall Storm Set to Slam Manitoba With Rain, Snow, and Strong Winds

Brad Leave a comment

A potent fall storm brewing in Alberta will race eastwards across the Prairies today, strengthening substantially as it does. It will move through Southern Manitoba tonight and tomorrow, bringing rain, snow, and strong winds to the region. As it passes, it will also mark a substantial shift in the large-scale weather pattern that will bring much cooler temperatures to Winnipeg over the next week.

Today will be Winnipeg’s warmest day for the foreseeable future as seasonably mild air moves into the region ahead of the incoming low pressure system from Alberta. Temperatures will climb to around the 9°C mark with light northerly winds this morning switching out of the south for the afternoon. Skies will start off partly cloudy to mixed, but more and more cloud will move through the day, making for mainly cloudy conditions this afternoon.

The winds will strengthen in the evening to around 30 km/h as the low approaches, keeping temperatures mild at around 8 or 9°C well into the night. As the centre of the low moves through shortly after midnight, rain will begin spreading into the Red River Valley. Winds will back to the north shortly after midnight and intensify, reaching 40 gusting to 60 km/h by Thursday morning. At this point, we expect precipitation to remain as rain overnight with temperatures dropping to a low near +3°C; between 5 to 15 mm of rain is likely to fall overnight throughout the Red River Valley, with lower amounts near the U.S. increasing northwards towards Winnipeg and the southern Interlake.

NAM Forecast Precipitation Type and Intensity valid 09Z Thursday October 26, 2017
The forecast rain/snow line at 4 AM Thursday morning will cut through the Parkland and into the Interlake

For those further west in the southwest corner of the province or in the Manitoba Parkland, rain will change to snow overnight with lower amounts of 2 to 5 mm of rain and a dusting of snow in the southwest and higher amounts of 5 to 10 mm of rain and 2 to 4 cm of snow. The exception to the snowfall amounts will the along the Riding mountains and western escarpment, where strong northerly winds will enhance snowfall amounts. Localized accumulations of 10 to 20 cm will be possible in these regions.

NAM Forecast Precipitation Type and Intensity valid 15Z Thursday October 26, 2017
The rain is forecast to completely change over to snow in the Red River Valley by 10AM

Rain will transition to snow – potentially fairly heavy at times – early on Thursday morning in Winnipeg and spread southeastwards quickly through the remainder of the morning. Temperatures will drop to around 0 to +1°C through the morning as the northerly winds further intensify to 50 gusting to 70 km/h with the chance for gusts as high as 80 to 85 km/h. The strong winds will combine with the heavier bands of falling snow to produce poor visibilities in blowing snow. Additionally, road conditions will likely deteriorate through the day, although will be very sensitive to temperature.1 By the end of the day, Winnipeg will likely see around 3-6 cm of accumulated snow, however it may end up a little more, or a little less, depending on how much manages to melt.

NAMNEST Forecast 10m Wind Speed valid 18Z Thursday October 26, 2017
Widespread strong winds will be in place across southern Manitoba and the Dakotas

The strong winds will begin to diminish late in the afternoon, and then gradually taper off to around 20 km/h by Friday morning. The snow will ease to a few flurries in the afternoon and taper off by evening. Temperatures will dip to a low near -4°C.

So in summary, for Winnipeg, winds will intensify tonight to 40 gusting 60 km/h as rain moves into the region. Winnipeg can expect anywhere from 5-15 mm of rain tonight, but will switch over to snow early Thursday morning as winds increase further to 50 gusting 70 km/h. The gusty winds will persist through much of Thursday with moderate snow through the morning tapering off to flurries in the afternoon. Snowfall accumulations will be very sensitive to temperature, but it looks like the most likely outcome will be between 3-6 cm of snow, but should more intense bands develop over the city, up to 10 cm could pile up.

Friday will be comparatively pleasant, but cool. Winds will continue to taper off with partly cloudy skies and temperatures climbing to a high near +3°C. The clouds will clear out for Friday night as temperatures drop to a low in the -6 to -8°C range.

Long Range Outlook

The weekend looks like a bit of a mixed bag. Saturday will be cool but pleasant with a high near 5°C, light winds and fairly sunny skies. Things change on Sunday, though, as another low pressure system pushes into the province, bringing more cloud and the chance for more rain or snow.

Winnipeg’s seasonal daytime high is currently 7°C while the seasonal overnight low is -3°C.

  1. If temperatures remain closer to +1°C, roads will likely remain in relatively good shape until the freeze occurs on Thursday night, but if it dips closer to the freezing mark, area highways may become a bit slick through the afternoon. ↩