Tag: Flurries

Mild But Dreary Weather Continues

Brad Leave a comment

The weather pattern that has brought temperatures well above seasonal to Winnipeg[1] – despite the persistence of low cloud supplied by the outflow winds of a high pressure system to our southeast – will continue to pump warm Pacific air eastwards into the region for another couple days. By the end of the weekend, however, a cold front is set to push through bringing more seasonal temperatures back to the Prairies.

Friday
1°C / -2°C
Mainly cloudy
Saturay
3°C / -3°C
Mixed skies
Sunday
-1°C / -13°C
Mainly cloudy; slight chance of flurries

Winnipeg will see cloudy weather today as low cloud entrenched in the Red River Valley refuses to exit as southerly outflow winds continue to reinforce the low-level moisture trapped underneath the substantially warmer air just off the surface[2] that has spread over southern Manitoba.

The cloud will be accompanied by breezy southerly winds to 30-40km/h. The temperature will only climb to around 0 or +1°C today. Some clearing is possible later in the day as drier air begins pushing eastwards into the Dakotas and may work its way northwards in the flow. It’s far from certain, but we could see some breaks in the cloudy skies later today into the evening. Temperatures will drop to around -2°C tonight.

This Winnipeg forecast sounding – valid at 10AM CST Friday, December 12, 2014 – shows a thin layer of saturated air right at the surface which will continue to produce low-level cloud.
This Winnipeg forecast sounding – valid at 10AM CST Friday, December 12, 2014 – shows a thin layer of saturated air right at the surface which will continue to produce low-level cloud.

Saturday looks to bring mixed skies with a lot of uncertainty on exactly what we’ll see. Weather models want to clear things out fairly well and give us sunny skies with a high near 6°C. Unfortunately, I’m not entirely convinced that’s what will happen. The Red River Valley will sit on the cusp of where the return flow from the high pressure system meets drier air pushing in from the southwest. However, a low pressure system approaching from the west will likely back the winds slightly, tapping into the low-level moisture in the outflow winds from the high. Additionally, large-scale lift ahead of the low could also work to develop more low cloud ahead of the approaching cloud. So while the day may end up sunny, it seems a bit more likely we’ll see mixed skies or increasing cloud through the day. Due to that, I think the high will be closer to 3 or 4°C with temperatures dropping to around -3°C overnight under mainly cloudy skies.

Sunday will be a mainly cloudy day as a low pressure system passes to our south. Northwesterly winds will bring more seasonal Arctic air into the region through the day, limiting our daytime highs to -1°C with just a slight chance for some light flurries.

Through much of next week seasonal to slightly above seasonal temperatures are expect with no significant precipitation events in the forecast.

  1. Our daytime highs near -1°C are about 8°C above seasonal for this time of year.  ↩
  2. As shown in the figure mid-way through this post, while surface temperatures will struggle to climb just above 0°C, temperatures just 1.5km off the ground are nearly 17°C.  ↩

Another Blustery Day Leads Towards a Pattern Change

Brad Leave a comment

Today will be yet another blustery day in the Red River Valley as strong northwesterly winds sit over the region behind a low pressure system that passed through overnight. Blowing snow will be an issue in some rural areas, however little new snow and a couple days of compaction since Sunday’s snowfall should result in less blowing snow than was seen then. After one last shot of cold air settling over Southern Manitoba tonight, the large-scale pattern looks set to change and allow slightly milder air back into the region.

Wednesday
-9°C / -19°C
Mixed skies with a chance of flurries; windy with local blowing snow
Thursday
-10°C / -16°C
Mainly sunny
Friday
-5°C / -9°C
Mostly cloudy and breezy

Today’s most significant weather will be the strong northwesterly winds in place through the whole Red River Valley. Gusting as high as 60-70km/h, the strong winds will make the high of -9 or -8°C feel much colder with wind chill values in the -15 to -20 range. Blowing snow will be a bit of an issue in rural areas, however with little new snow and some time for Sunday’s snow to settle, reduced visibilities in blowing snow should be much less an issue today than it was for the end of the weekend. No significant accumulations are expected today in the Red River Valley, however there may be an isolated band of higher amounts in the lee of Lake Winnipeg.[1]

Tonight will see skies clear and winds taper off as temperatures dip down to a “chilliest-this-season” low near -19 or -20°C.

After a chilly start, Thursday will be another cool day. Fortunately, light winds will make things feel not nearly as bad as Wednesday as temperatures climb towards a high near -10°C. Skies will remain mainly clear[2] on Thursday night as temperatures dip down to around -16°C.

Big Warm-Up in Store for End of Week

After a considerable amount of time with below-normal temperatures, things look set to switch around dramatically on Friday as the upper-level ridge that’s been in place for much of November over British Columbia completely collapses and a zonal flow brings milder temperatures eastwards across the Prairies.

The 850mb temperature & wind forecast for Thursday evening show a clear warm front pushing eastwards across the Prairies.
The 850mb temperature & wind forecast for Thursday evening show a clear warm front pushing eastwards across the Prairies.

The milder air will bring a fair amount of cloud cover with it as it spreads eastwards, resulting in a mostly cloudy day in Winnipeg as temperatures climb to a relatively balmy -5°C or so. Unfortunately, with all the mild air attempting to move in, strong southerly winds to around 40-50km/h will likely develop, keeping things feeling cooler than it would otherwise. There may be a slight chance of some light flurry activity in the Red River Valley along the warm front in the afternoon, but at this point it looks insignificant.

Mild air will continue to push eastwards on Friday night, and the Red River Valley should find itself into the warm sector of this low pressure system. As a result, overnight lows will be considerably warmer than we’ve seen lately. Expect temperatures to drop to around -8 to -10°C on Friday night under partly cloudy skies.

Mild Weekend Ahead

We should see more pleasant weather on Saturday with a fair amount of sunshine and lighter winds as the temperature climbs to around -4°C.[3] Sunday continues the mild trend, however the milder temperatures will be sustained by a low pressure system tracking along the U.S. border.

The GDPS 12hr. precipitation accumulation for Sunday morning to evening shows a large swath of snowfall through Western Manitoba & the Interlake, just brushing the northern Red River Valley.
The GDPS 12hr. precipitation accumulation for Sunday morning to evening shows a large swath of snowfall through Western Manitoba & the Interlake, just brushing the northern Red River Valley.

This system looks like it has the potential to bring a swath of 10+cm of snow to the Interlake westwards towards the terrain west of lakes Winnipegosis and Manitoba. Given how far out this system is, there’s a lot of details up in the air[4] and slight variations in track or intensity could dramatically shift/impact the snow event. We’ll be keeping an eye on it, but for now just keep it in the back of your head that the weekend could be ending with what could be the heaviest large-scale snow event so far this season.

  1. Very little is expected in the way of lake-induced flurry activity to the lee of lake Manitoba now that it’s mainly ice covered.  ↩
  2. Much of the night should be mainly clear, however some cloud may sneak in late in the overnight period associated with Friday’s system.  ↩
  3. The potential for highs closer to -2 or -1°C exists, but I’d rather wait until closer before getting anybody’s hopes up.  ↩
  4. Rimshot  ↩

Remaining Cold

Scott Leave a comment

This week will remain cold as arctic air continues to spill down from the north.

A northwesterly flow will continue to bring cold weather to southern Manitoba on Monday
A northwesterly flow will continue to bring cold weather to southern Manitoba on Monday

Monday

Monday
-8°C / -14°C
Mix of sun and cloud with chance of flurries

Today will be cold and breezy. Temperatures in the morning will be in the minus teens, rising into the minus single digits by afternoon. Skies will be a mix of sun and cloud with chance of light flurries. The wind will be from the north-west at 20-30km/h.

Tuesday

Tuesday
-7°C / -10°C
Mix of sun and cloud with chance of flurries

Tuesday will be slightly warmer than Monday, but not by much. High temperatures will once again be in the minus single digits, once again under a mix of sun and cloud. There will also be a chance of light flurries throughout the day. Winds will be breezy and from the south.

Wednesday

Wednesday
-9°C / -18°C
Mainly cloudy with flurries

Wednesday looks to be a fairly miserable day. High temperatures will be near the -10C mark, with a gusty north-west wind and flurries. This means blowing snow is likely in open areas, similar to the conditions experienced on Sunday. Winds speeds of 40km/h gusting to 60km/h are expected.

Long Range

The long range forecast calls for continued cold weather. Weather models suggest that we’ll see below-normal weather persist for at least another week. Unfortunately, it looks like winter is here to stay, like it or not.

Cool and Quiet Weather Ahead

Brad Leave a comment

Fairly quiet weather is on tap for Winnipeg as the Arctic air mass that has been entrenched over the region is reinforced by numerous weak systems drifting southwards in the northerly flow over the province. As a result, temperatures will remain well below normal through the weekend with some flurry activity possible.

Friday
-7°C / -15°C
Mainly sunny
Saturday
-8°C / -15°C
Mixed skies with a chance of light flurries
Sunday
-6°C / -12°C
Mainly cloudy with a few flurries

Today will be the nicest day of the next few with sunny skies as we head towards a high of around -7°C. Winds will be relatively light out of the west at 15-25km/h. Tonight will see a low near -15°C.

Saturday will bring mixed skies once again with a high near 8°C as winds shift back to northwesterly behind a weak trough moving through and lake-effect flurries start up again. No accumulations are expected, but you may see a few flakes in the air throughout the day on Saturday. Heading into Saturday night, a low pressure system that is making an extrodinary trip from essentially the North Pole straight to Southern Manitoba will begin working into the region. Cloud and a few flurries will spread into the region ahead of it through Saturday night.

The incredibly amplified flow over North America will bring a low pressure system from the high arctic straight south through Manitoba this weekend.
The incredibly amplified flow over North America will bring a low pressure system from the high arctic straight south through Manitoba this weekend.

Sunday will be a mainly cloudy day with some light flurries through the Red River Valley. Northwesterly winds will result in some slightly heavier snow in the lee of the Manitoba lakes, however no significant accumulations are expected. The ability for the lakes to produce heavy snowfall is rapidly diminishing as ice cover continues to grow and expand, covering up the open water.

With all the cloud around and northwesterly winds in place, temperatures should climb a couple degrees warmer than Friday or Saturday to around -6 or -5°C. Heading into Sunday night, the clouds will likely break up a little bit, although the chance for flurries will continue. The low should drop to around -12°C, however it may end up a couple degrees warmer or cooler depending exactly on how much clearing takes place.

Quiet Pattern Continues

Looking ahead to next week, temperatures look to remain fairly steady with little expected for snowfall. Long-range outlooks show a move out from below-normal temperatures, but that’s more a result of the normal highs gradually falling. No major snowfalls are in the foreseeable future.