Tag: Windy

Bitter Cold Seizes Winnipeg

Brad 1 Comment

Some of the coldest temperatures of the year are on tap for Winnipeg as a final blast of Arctic air spills across Southern Manitoba. The bitter cold will be short-lived, however, as a major pattern change this weekend will begin spreading significantly milder air across the Prairies.

Today will be a cold one with a ridge of high pressure clearing skies out early this morning and temperatures reaching a high temperature of just -22°C. Winds will start the day off out of the west at around 20 km/h and shift to the south in the afternoon.

A weak low pressure system will round the base of the Polar Vortex tonight, swinging across southern Manitoba and bringing cloudy skies and some light flurry activity. The cloud cover will help prevent temperatures from dropping too low; early tonight temperatures will drop to around -26 or -27°C, but then begin to warm as the cloud moves in. By Thursday morning, the temperature will have climbed back to around the -20°C mark. No significant snow accumulations are expected.

A wide area of flurries are expected on Wednesday night with the passage of a weak low pressure system.

The overnight warming trend is all a cruel ruse, however, as winds shift northwesterly early Thursday and start ushering in the really cold air. Winds will strengthen to 30-40 km/h with gusts up to 50 km/h or so while temperatures drop to around -23°C. They’ll remain steady there as skies clear and winds gradually diminish through the afternoon.

A potent Arctic high pressure system will move in on Thursday night, bringing light winds and extremely cold temperatures. Extreme cold warnings are highly likely across all of Southern Manitoba on Thursday night as temperatures plummet to overnight lows in the -30 to -34°C range. At these temperatures, winds of just 5-12 km/h will produce wind chill values of -401 and winds of that speed are produced simply by the movement of the air as it cools. By late overnight into Friday morning wind chill values will be in the -40 to -45 range.

Friday will be a very tricky day with respect to temperatures. Warmer air will begin working into the region from the west as a low pressure system building into the northern Prairies begins shunting the cold air to the southeast. However, winds will increase out of the south to southeast, feeding cold air out of the Arctic ridge back up the Red River Valley. In a best-case scenario, temperatures would likely climb to a high near -17°C, but if the cold air clings on, temperatures will languish with highs near -21°C.

That said, it won’t feel great outside as winds out of the south strengthen to 30-40 km/h. Skies will be mainly clear through the day. Winds will taper off in the evening and temperatures will remain steady through the night with just a few clouds.

Long Range

The story changes next week: nothing but above-normal temperatures flooding the Prairies.

Above-normal temperatures (red) will spread eastwards across the Prairies by Monday.

The jet stream will shift northwards for next week, drawing mild Pacific air across the Rockies and the Prairies. An extended period of mild temperatures are expected with daytime highs climbing from around -6°C on Sunday to the 0°C mark by mid-week. The mild weather will likely continue through next weekend. Hooray!

Winnipeg’s seasonal daytime high is currently -13°C while the seasonal overnight low is -24°C.

  1. This wind chill value is Environment Canada’s criteria for issuing an extreme cold warning. ↩

More Snow as Colorado Low Grazes Manitoba

Brad Leave a comment

More snow is on the way for Southern Manitoba as a Colorado Low grazes the region as it moves through the Dakotas and Minnesota. After the passage of that system, the upper-level pattern will shift and bitterly cold Arctic air will spill southeastward across the Prairies.

Snow will build into Southern Manitoba through the day today from the southwest, with a few isolated flurries in the morning intensifying into more persistent snow through the afternoon. By 6PM, most areas along and south of the Trans-Canada Highway will be seeing snow. The snow will persist through much of the night before tapering off on Tuesday morning.

NAM-based accumulated snowfall for the next storm based on a 10:1 snow ratio.

The NAM model pictured above has been consistently producing a total of between 6-8 cm at a 10:1 snowfall ratio (SLR), however it appears likely that the SLR will be higher at around 14:1, which would push storm-total snowfall ranges in the Red River Valley from around 8-12 cm in Winnipeg to 10-20 cm near the US border. Amounts States-side will be higher, with nearly 25cm of snow expected through east-central North Dakota into Minnesota.

Temperatures will be seasonal with highs in the -9 to -11°C range today and temperatures dropping to -18°C by Tuesday morning.

Winds will be breezy through the day today out of the northeast at around 20-30 km/h. As Winnipeg & the Red River Valley move onto the back-side of this system tonight, winds will strengthen out of the north to northwest to around 40 km/h. These gusty winds will combine with the fresh snowfall to produce blowing snow on area highways with locally poor visibilities. The winds will begin to ease through the early afternoon, bringing an end to the blowing snow.

Cooler Weather For The Remainder Of The Week

Temperatures will be much cooler on Tuesday with little movement from the overnight low near -18°C as colder air moves into the region from the northwest. Even colder conditions will move in on Tuesday night with overnight lows expected to drop to around the -27°C mark. Wednesday will see Winnipeg & the Red River Valley entrenched in the Arctic air with highs near the -22°C mark and an overnight low dipping back down to around the -27°C mark.

The upcoming cold snap can be seen in this forecast for the second half of the week showing the cold air aloft building into Southern Manitoba.

Skies on Tuesday will remain fairly cloudy until the late afternoon when things begin to break up. It doesn’t appear that this cold snap will be associated with particularly sunny skies, though. The main ridge axis will pass well to our west, making it more difficult for all of the cloud to clear from Southern Manitoba. The Red River Valley will mainly see mixed to cloudy skies through much of the week.

Long Range

Little pattern change is expected in the next 7-10 days.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid January 9-16, 2016

As this NAEFS outlook shows, below-normal temperatures will likely remain in place for the next 1-2 weeks. Temperatures may moderate next week to be closer, but still below, seasonal values. Conditions look fairly dry with little snow expected; the next potential for some snow may be with a clipper system early next week.

So after this snowfall, Winnipeg & region will be falling into a relatively quiet and cold pattern, holding strong for at least the next 7-10 days.

Winnipeg’s seasonal daytime high is currently -13°C while the seasonal overnight low is -23°C.

Major Winter Storm Moving In

Scott 1 Comment
Environment Canada has issued a Winter Storm Warning for this system.

A major winter storm is moving in as you read this article. It will bring the first serious snowfall of the year to the Red River Valley, with heavy blowing snow or even blizzard conditions possible in many areas. You may want to reconsider any travel plans early this week!

A strong low pressure system will bring heavy snow and strong winds to southern Manitoba early this week
A strong low pressure system will bring heavy snow and strong winds to southern Manitoba early this week

Today

Monday
0°C / -2°C
Snow beginning

A strong low pressure system will move off the Rocky Mountains and into North Dakota today. It will spread moderate to heavy snowfall into parts of western Manitoba this morning, before snow spreads over the rest of southern Manitoba later in the day. Snowfall will fall for the entire day in most of western Manitoba, with total accumulations of 10-15 cm expected in most areas. Further east, the Red River Valley will see lesser amounts today, with 2-5 cm in the Winnipeg area and more like 5-10 cm near the International border. Local amounts of 15 cm may occur along the International border in south-central Manitoba. Winds will be gusty from the east at 20-30 km/h, producing some blowing and drifting snow.

Tuesday

Tuesday
-2°C / -4°C
Blizzard Developing with Heavy Snow

Conditions will really begin to deteriorate early Tuesday as winds shift to the northwest. Snow will continue to fall as well, with an additional 10-20 cm possible in the Red River Valley on Tuesday. Snow will taper off in southwestern Manitoba, but another 2-5 cm will be possible. The northwesterly winds that develop will be strong at 40 km/h gusting to 60 km/h, with higher values of 50 km/h gusting to 70 km/h in some treeless areas. This will likely result in blizzard conditions over large parts of southern Manitoba, especially south and west of Winnipeg. Those areas that don’t quite meet blizzard criteria will certainly see heavy blowing and drifting snow, with travel becoming difficult or impossible in some areas. Road closures are likely, especially the Trans-Canada Highway west of Winnipeg and Highway 75 south of Winnipeg. Conditions will not improve significantly until early Wednesday.

Expect storm-total snowfall accumulations by Wednesday morning.
Expect storm-total snowfall accumulations by Wednesday morning.

Wednesday

Wednesday
-12°C / -20°C
Snow and blizzard ending

Snow should finally taper off on Wednesday morning in all of southern Manitoba, but not until most areas have received significant accumulations of snow. Southwestern Manitoba can expect 15-25 cm, while Winnipeg can expect 10-20 cm. Areas along the International border in south-central Manitoba can expect to receive 20-30 cm. Locally higher amounts may occur where heavier bands of snow persist for a longer period of time. Large snow drifts will be a problem on Wednesday, even once the snow ends. Some rural roads may be impassable due to heavy drifting. Blowing snow will persist on Wednesday, but winds will slowly decrease throughout the day. Temperatures will have dropped noticeably on Wednesday as this system begins to pull down a cold arctic air mass.

Long Range

Conditions will finally calm down on Thursday as winds taper off. However, in the wake of this strong low we’ll see a blast of arctic air, with temperatures likely dropping into the minus twenties on Thursday and Friday. This frigid pattern is expected to persist for awhile, so make sure to get out those winter clothes!

Colorado Low Looms

Scott Leave a comment

Our first significant Colorado Low in some time will bring a variety of precipitation types to southern Manitoba today. Rain, snow, freezing rain, and ice pellets will be possible.

A variety of precipitation types will be possible in southern Manitoba today. The map shows areas of rain (green), snow (blue), freezing rain (purple), and ice pellets (red).
A variety of precipitation types will be possible in southern Manitoba today. The map shows areas of rain (green), snow (blue), freezing rain (purple), and ice pellets (red).

Today

Monday
2°C / 1°C
Mixed precipitation early, then rain

A powerful Colorado Low will bring a mixed-bag of precipitation to southern Manitoba today. Precipitation will likely start out as freezing rain or ice pellets in portions of the Red River Valley and south-eastern Manitoba this morning, before changing to rain later in the morning. Rainfall amounts of 5-10 mm are expected in most areas, with higher amounts possible near the International border. There may be a bit of snow at times, but little accumulation is expected – and any that were to accumulate will be melted by rain later in the day. However, the story will be different in western Manitoba, where snow will be the dominant precipitation mode for the day. Accumulations of 5-10 cm are likely in most areas by tonight. Winds will be gusty out of the north-east at 30 km/h gusting to 50 km/h, bringing some blowing and drifting to open parts of western Manitoba.

Tuesday

Tuesday
1°C / -1°C
Periods of snow

This Colorado Low will take its time exiting our region, affecting us once again on Tuesday. Unfortunately (for some), rain will change to snow on Tuesday in the Red River Valley and south-eastern Manitoba. Accumulations of 4-8 cm are likely in addition to possibly a couple millimetres of rain or mixed precipitation early in the day. Western Manitoba can expect another 5-10 cm on Tuesday, bringing totals up to 10-20 cm. The model graphic shown below, which considers a wide-range of possible solution, shows a very high probability (>80%) of over 10 mm of total precipitation in most of southern Manitoba. Winds will remain gusty out of the north on Tuesday at 30 km/h gusting to 50 km/h.

Most of southern Manitoba stands a very high chance of receiving over 10 mm of precipitation with this system (NAEFS graphic).
Most of southern Manitoba stands a very high chance of receiving over 10 mm of precipitation with this system (NAEFS graphic).

Wednesday

Wednesday
-1°C / -4°C
Mainly cloudy with flurries

The Colorado Low will continue to linger on Wednesday, but snowfall rates will decrease. Flurries are expected throughout the day, but accumulations should be small. Winds will remain breezy from the north at 20-30 km/h.

Long Range

It appears that we’ll see generally seasonal to slightly-above seasonal temperatures as we move into early December. However, longer-range models do hint at a very cold arctic air mass being pulling down from the north about one week into the month. This will have to be monitored, as it would be our first significant bought of below-normal temperatures in quite awhile.