Alberta Clipper Brings Back the Deep Freeze

After enjoying a well above-normal –2°C daytime high on Monday, things are set to plunge back into the deep freeze as an Alberta Clipper low pressure system tracks into Ontario and allows a new supply of very cold Arctic air to surge southwards across the Prairies.

The Clipper

Wednesday

-9°C / -26°C
Mostly cloudy; flurries likely. Windy.

A potent Alberta Clipper will move through Manitoba today with the bulk of it’s snow falling along a line from Flin Flon through Norway House and Beren’s River where anywhere from 4–10cm can be expected. Further south, we’ll see light snow through the Parkland and Interlake through much of the day, but the snow won’t start in earnest until the afternoon along and south of the Trans-Canada Highway when the cold front associated with this system moves through.

And what a cold front it is! Yesterday saw genuine flash-freezes in the high plains of the Rockies; Dawson Creek, BC had it’s temperature fall from +5°C to –16°C in just 3 hours. In Grand Prairie, AB temperatures plummeted similarly, with temperatures falling from +5°C to –15°C in just 3 hours as well. It’s this intense blast of arctic air which will help this system produce snow despite the fact it is lacking considerable moisture.

While temperatures won’t be set to plummet quite so dramatically further east in Manitoba, we’ll certainly see the cold air return with a blast. We’ll be dealing with snow, wind, blowing snow and bitterly cold temperatures/wind chill by the end of the day today. Here’s what you can expect:

Snow: We’ll likely see scattered light flurries through the morning and early afternoon. Marginally more organized snow will try to push in through the afternoon along the cold front, but the system will have difficulty producing much snowfall anywhere other than along the northern edge of the track of the low pressure system. By the time things taper off this evening, anywhere from just a trace of snow to 2–3cm will likely have fallen in Winnipeg & the Red River Valley.

Wind & Blowing Snow: Winds will remain fairly light through the day until the passage of the cold front early this afternoon. Behind the front the winds will flip to the northwest and pick up strength to 30–40km/h with gusts as high as 60km/h. This wind will couple with the loose snow on the ground and the falling snow to produce widespread blowing snow through much of the Red River Valley. The worst areas for blowing snow will be the western and central RRV on any west-east running roads, including the Trans-Canada Highway between Winnipeg & Portage la Prairie. If you have plans to travel west on the Trans-Canada Highway today, be prepared for slippery roads with snow and blowing snow producing very poor visibilities.

Falling Temperatures/Wind Chill: Temperatures will fall quite aggressively behind the cold front with temperatures dropping from our daytime high of around –9°C to an overnight low of around –26°C. The cold temperatures coupled with the wind will produce wind chill values near –35 through the overnight hours.

The Remainder of the Week

Thursday

-21°C / -28°C
Sunny & cold.

The remainder of the week through the beginning of next week will be marked by the presence of yet another significant Arctic air mass entrenched over the Prairies. We’ll see mainly sunny skies on Thursday with light winds but temperatures will be very cold. Our high will only climb to around –22 or –21°C before plummeting back down to –28 or –29°C for our overnight low on Thursday night.

Friday

-17°C / -25°C
Some afternoon cloud.

Temperatures will climb a little higher on Friday as a very weak disturbance ripples down the northwest flow, spilling a little bit of cloud across Southern Manitoba by the afternoon hours. The temperature will climb up to around –17°C and we’ll see the temperature drop to around –25°C on Friday night.

Things look clear and cold for the weekend. Another shot of Arctic air will push into the Red River Valley bringing another batch of bitterly cold temperatures and overnight lows near –30°C.

October Won’t Have a Scary Start

October won’t start off with any scary weather, but I can guarantee the month will end on a frightening note!

Tuesday Will be a Very Windy Day in Southern Manitoba

Monday

Monday

Mix of Sun and Cloud. Chance of Showers Late.
22°C / 8°C

Today will be a nice day in Southern Manitoba. Temperatures will be in the low twenties, under a mix of sun and cloud. The wind will be breezy and from the south-west. A cold front will push through Southern Manitoba on Monday night, setting up a cooler Tuesday. There may also be some light rain showers associated with this front, but it will be a hit and miss type of rain event.

Tuesday and Wednesday

Tuesday

Increasing Cloudiness
17°C / 4°C
Wednesday

Mix of Sun and Cloud
15°C / 6°C

The first day of October will neither be really good, nor really bad. On the one hand it will be a seasonably warm day, with temperatures in the mid to upper teens. However, it will also be a very windy day, with westerly winds of 40-50km/h gusting to 60-70km/h (winds may reach 60km/h gusting to 80km/h on a localized basis). Unfortunately, that strong wind will make conditions much less pleasant than they otherwise would be.

Wednesday looks to be much less windy than Tuesday, but it will still be on the breezy side. Temperatures will be in the mid teens, with a westerly wind of 20-30km/h gusting to 40-50km/h.

Long Range

The long range forecast is looking more October-like. Another cold front is currently forecast to move through Manitoba on Wednesday night, bringing in cooler conditions to end the week. Models are also hinting at a strong low pressure system passing near or just south of Manitoba later this week. Should this system take a more northern track, it could impact Southern Manitoba…but it’s too early to say.

Active Weather Pattern, but Inactive Weather?

A couple of weather systems are in store for this week, but that doesn’t mean the forecast is wet for everyone.

A Cold Front Will be Positioned Through Manitoba on Monday

Monday

Monday

Mix of Sun and Cloud. Chance of Showers.
22°C / 8°C

Today will be a warm day by late September standards. High temperatures will be in the low twenties in the Red River Valley. A bit further east in south-eastern Manitoba some areas may approach the mid twenties. But a bit further west in western Manitoba, temperatures will struggle to reach the upper teens. The discrepancy in temperatures over Southern Manitoba today is resulting from a cold front located over western Manitoba. In the vicinity of this front there is extensive cloud cover and some rain activity. Further east, skies are clearer, allowing for the atmosphere to heat up a bit more. Some of the rain showers over western Manitoba may sneak into the Red River Valley later today (as cloudiness increases later today), but little in the way of accumulating rain is expected. Over western Manitoba the rain will probably amount to between 5 and 15mm in general.

Tuesday

Tuesday

Mainly Sunny
21°C / 7°C

Surprisingly, Tuesday will be quite a nice day despite the passage of a cold front on Monday night. High temperatures on Tuesday will be in the upper teens or lower twenties in Southern Manitoba, under sunny skies and light westerly winds.

Wednesday

Wednesday

Mainly Cloudy
22°C / 14°C

Wednesday will see cloudier conditions return ahead of a developing weather system. Temperatures on Wednesday are expected to max out in the low twenties in Southern Manitoba and the wind will be gusty and from the south-east. Some rain may occur over Western Manitoba on Wednesday, but it’s too early to speculate on the location or intensity of it.

Long Range

The long range outlook will be dominated initially be the weather system mentioned in Wednesday’s forecast. This low pressure system is currently expected to track through Manitoba, with its main impacts likely to be confined to the Western half of the province. However, it is possible that this system may change track, so it could potentially affect other parts of Manitoba as well – more details on that will be available in Wednesday’s post.

Once that weather system passes by, conditions should return to near seasonal values for the end of the week. Next weekend is looking fairly pleasant, with near to slightly above seasonably temperatures…but of course that could change before the weekend actually arrives!

Warming Up, Just to Get Knocked Back Down

Temperatures will rebound early this week, but a big weather-maker may interrupt that warm-up by midweek.

Warmer air will move into Southern Manitoba on Monday, but it will be windy.

Monday

Monday

Sunny
21°C / 9°C

Today will be bright and sunny with temperatures improving over Sunday’s cool values. Highs will be in the low twenties over Southern Manitoba, which is quite a recovery from this morning’s lows, which were around freezing. The only downside to today’s weather will be a stiff southerly wind that will be 30 to 40km/h gusting to 50 to 60km/h by late afternoon.

Tuesday

Tuesday

Mainly Sunny
27°C / 13°C

Tuesday will be one of the warmest, if not the warmest, days this week with high temperatures in the mid to upper twenties. The humidity may even increase a bit by late in the day over some portions of Southern Manitoba. It certainly won’t be an oppressive mid-summer type of humidity, but may be noticeable nonetheless. Tuesday will be slightly less windy compared to Monday, but the wind will still be fairly strong and from the south.

Wednesday

Wednesday

Mix of Sun and Cloud. Rain late. Risk of a thunderstorm.
25°C / 17°C

What has been a fairly boring weather pattern so far this September may begin to take an interesting turn on Wednesday. A strong low pressure system is forecast to develop in the lee of the Rockies on Tuesday and move eastward into North Dakota by Wednesday. This system will prompt seasonably high moisture values to stream northward into the Dakotas and Southern Manitoba. This moisture will help to destabilize the atmosphere over a large part of the North-Central US, perhaps extending up into Southern Manitoba. This system will also pump warm air up into the region, with models currently suggesting temperatures will once again reach the mid to upper twenties in Southern Manitoba on Wednesday.

As this strong low pressure system interacts with that unstable environment, numerous thunderstorms may develop on Wednesday through Wednesday night. These storms may affect parts of Southern Manitoba at some point on Wednesday or early Thursday. Given the nature of this system it looks like the main severe threat will be heavy rain. However, it is too early to rule out the possibility of other forms of severe weather. We’ll have more updates on this system as the week progresses.

Long Range

The long range forecast will largely be determined by what happens with Wednesday’s system. At this point it appears likely that we’ll receive rain from this system, but the timing of that rain is too early to predict. Unfortunately, once this system moves out of our area it will deliver a parting shot of cold air, which will probably set up a chilly weekend. Again, how cold it will get is still not certain, but getting above seasonal values next weekend may be a struggle.