Cool Weather Continues

A large upper-level low pressure system over northern Ontario will bring us chilly weather to start the week. Unfortunately, this means below-normal temperatures and frequent opportunities for showers.

 An upper low over Ontario will bring cool conditions to southern Manitoba this week
An upper low over Ontario will bring cool conditions to southern Manitoba this week

Monday

Monday
7°C / 2°C
Mainly cloudy with chance of showers

Today will be cool, cloudy, and breezy as that large upper-level low over Ontario brings a cool north-westerly flow to southern Manitoba. There will be a chance of showers throughout the day, as a band of light precipitation pushes down from the north.

Tuesday

Tuesday
7°C / -1°C
Mainly cloudy

Tuesday’s weather will be very similar to today’s. Skies will once again be mainly cloudy with a chance of showers. Unfortunately, it will also remain breezy as that upper low to our east maintains a decent pressure gradient across Manitoba.

Wednesday

Wednesday
8°C / -3°C
Mix of sun and cloud

It looks like Wednesday’s weather may begin to see some improvement over the conditions from earlier in the week. Temperature won’t warm by much, but winds should be a bit lighter. The chance for showers looks to be gone on Wednesday, and we should even see some sunshine.

Long Range

The long range forecast isn’t looking all that great at this point. The current forecast calls for a surface high to build into Manitoba late this week as that nasty upper low finally moves off. This will likely mean sunnier skies, but also a good chance for some solid freezing nights, and relatively cool daytime temperatures. Models hint at a warming trend from next weekend into the following week, though it isn’t currently expected to be an extended warm-spell…but we shall see what actually happens!

Another Cold Snap in Southern Manitoba

Moderately miserable, categorically cold; the weather leading into this weekend will be fairly miserable as a large low pressure system moving through Ontario exerts its influence over southern Manitoba causing strong northwesterly winds as the coldest shot yet of Arctic air plunges southwards into the United States.

Friday
5°C / -1 to 2°C
Cloudy with showers. Flurries possible in the morning. Strong NW wind to 50km/h.

Saturday
7°C / 0–2°C
Clearing except cloudy in the lee of the lakes

Sunday
9°C / 3°C
Mixed skies with a slight chance of isolated showers or drizzle

Friday: A Miserable Fall Storm

The Red River Valley will be under the grip of a miserable fall storm lifting northwards through Northern Ontario today, driven by a massive push of cold Arctic air sweeping through Manitoba. We’ll see a very cold start to the morning with temperatures hovering around 2–3°C, strong northerly winds at 40–50km/h with gusts as high as 70–75km/h and a band of rain stretching north-south through the region. Embedded within the band will likely be some convection, significant since increased precipitation intensity could mean that in addition to the rain, we might see brief bursts of snow as well.

The precipitation should taper off by early afternoon, but we’ll still be left with a strong northerly wind and temperatures struggling to get to our high of 5°C. If the sun manages to poke out at all, we may eke out a 6°C for a high, but that looks quite unlikely.

The RDPS clearly shows Winnipeg nestled between two bands of lake-effect precipitation on Friday night.
The RDPS clearly shows Winnipeg nestled between two bands of lake-effect precipitation on Friday night.

Winds will begin to taper off tonight to around 20km/h. Combined with the cold air, the lake-effect machine will likely start up again, producing lake-effect showers or snow through the overnight period across regions in the lee of the lakes. At this point it looks like Winnipeg will remain safely between the two bands of lake-effect precipitation. The overnight low will be anywhere from –1 to 2°C, depending on exactly how much cloud remains in the area. Here in Winnipeg we should end up on the colder end of things under clearing skies.

A Chilly Weekend

It will be a chilly weekend in Winnipeg with temperatures on Saturday and Sunday both climbing only into the mid-to-upper single digits. Saturday should be a fairly nice day with mainly sunny skies in Winnipeg, but just to our west and east, lake-effect cloud (and likely precipitation) will be ruining a few people’s day. Temperatures will dip to the 0 to 2°C range Saturday night with just a few clouds. Again, lake-effect cloud will be present in the lee of the lakes.

Sunday will bring mixed skies as the whole storm system begins backing into Northern Manitoba from Ontario. Rain or snow will push through Central Manitoba into the Interlake through the day, spreading cloud ahead of it. Winds don’t look too bad this time – only around 20–30km/h – and precipitation should hold off in Winnipeg until overnight. Temperatures will drop to around 3–4°C on Sunday night, heading into a cool and showery Monday.

October Starts By Heading into Chilly Weather

Temperatures will be on the slide as a low pressure system bringing unsettled weather today draws in cooler air behind it, plunging southern Manitoba into yet another spell of unseasonably cool weather.

Wednesday
17°C / 10°C
Cloudy with a few showers

Thursday
16°C / 5°C
Mainly sunny, showers likely in the evening

Friday
10°C / 1°C
A few sunny breaks, otherwise mainly cloudy with light showers

Wednesday

Today will be a mainly cloudy day here in Winnipeg with rather pleasant temperatures – highs will be around 16 or 17°C – alongside a brisk southerly wind to 30–40km/h. The warmer temperatures are thanks to a strongly wound-up low pressure system lifting northwards near the Manitoba-Saskatchewan border. It will spread an area of rain through Manitoba, but the bulk of it should be isolated along the main deformation axis of the system, sliding northwards through SW Manitoba and Parkland Manitoba into the northern half of the province. Scattered showers will likely be seen through the Red River Valley, but it doesn’t seem like much organized precipitation will develop; as such, rainfall amounts should remain fairly low over the region.

Total precipitation forecast by the RDPS from 7AM to 7PM today.
Total precipitation forecast by the RDPS from 7AM to 7PM today.

Skies will remain mostly cloudy this evening with a chance for some shower activity continuing until around the middle of the night. Clearing will begin afterwards as we head to a low of around 5°C.

Thursday

Thursday will actually be quite a pleasant day; most of the cloud cover should be off to our east leaving us with quite a bit of sunshine through the day as we head to a high once again around 16°C. By late afternoon, though, skies should begin to cloud up in advance of a potent shortwave barreling down in the northwesterly flow behind today’s system. Showers will develop under the shortwave as it progresses southeastwards with much of the Red River Valley seeing some amount of rainfall before 9PM or so. There is a slight chance of seeing some lightning or small hail in some of the shower activity if it manages to develop intensely enough.

A simulated RADAR image from the NAM depicting the potent shortwave moving through on Thursday.
A simulated RADAR image from the NAM depicting the potent shortwave moving through on Thursday.

A brief reprieve will be in store for the middle of the night, but more shower activity is expected to move through later overnight into Friday morning on the back-side of the shortwave. The temperature will dip to around 5°C.

Friday

Friday will start off cloudy with a few remnant showers from the shortwave pulling off to the east. The shower activity should move off relatively quickly, but there’s a slight chance things will linger a little longer if the shortwave stalls out over SE Manitoba. Afterwards we’ll be entrenched in a northwesterly flow with Arctic air spilling southwards into the province. Our temperature will top out around 10°C with some lake-effect drizzle/showers likely in the lee of the lakes.[1]

The Arctic air mass moving in will be the coldest air mass of the season so far in Southern Manitoba. Temperatures will drop to 0–2°C on Friday night under mainly clear skies and a brisk northwesterly wind. Some areas will see cloud streaming off of the lakes, again though where that cloud goes will depend exactly on which way the wind blows.

Cool Weekend Ahead

This weekend will be a cool one as cold Arctic air entrenches itself over the province. Daytime highs will sit in the low teens with overnight lows in the low single digits, perhaps even dipping just below 0°C. Sunday may bring the chance for some shower activity pushing in from the east, but things look rather uncertain at this point.


  1. The wind direction makes it look unlikely that the lake-effect activity will push into Winnipeg; keep in mind that which areas see lake-effect precipitation is extremely sensitive to wind direction.  ↩

Fall-like Weather Returns

After a week of summer-like weather, conditions will return to reality. More fall-like temperatures are expected this week along with some rain.

Cool conditions will dominate our weather on Monday
Cool conditions will dominate our weather on Monday

Monday

Monday
12°C / 8°C
Mainly cloudy

Today will be mainly cloudy with a chance of an isolated shower or drizzle. Low-level moisture under a strong ridge of high pressure will be responsible for the cloud. We may see some clearing late in the day, but that won’t change the day’s expected temperatures. High temperatures today will be in the low teens, with a light easterly to south-easterly wind.

Tuesday

Tuesday
16°C / 10°C
Mainly cloudy

Tuesday will remain on the cool side, with temperatures in the low to mid teens. Despite the fact that these temperatures may seem cool, especially compared to last week, they are actually near normal for this time of year. Our next chance for rain will begin on Tuesday night as a compact, but intense, low pressure system spreads rain over southern Manitoba.

Wednesday

Wednesday
18°C / 8°C
Periods of rain

The aforementioned low pressure system will be the dominant weather feature on Wednesday. It is expected to bring light to moderate rainfall to southern Manitoba for most of Wednesday. It is too early to predict how much rain will fall, but at this point 5-10 mm looks most probable.

Long Range

The long range forecast looks very fall-like. Current modelling suggests we will see normal to below-normal weather as we move into October. That means temperatures in the low teens, plus or minus a few degrees.