Colder Conditions Arrive

Today marks the start of an extended period of seasonably cold conditions for Winnipeg.

A low pressure system skirting along the International border will bring cloudy conditions to the Red River Valley today. It will spread an area of rain across the region with up to 10 mm possible along the border. Amounts will quickly diminish northwards, though, with just a bit of light rain likely this morning in Winnipeg. Behind this low, a brisk northerly wind near 30 gusting 50 km/h will develop and usher in a much cooler air mass. Temperatures will only reach around 8 °C today, already several degrees below the seasonal average of 11 °C. The cloud cover will break up a bit tonight as the winds gradually ease. The city will see a low near -3 °C. Hard freezes will be common from here out.

From Thursday forwards, the region will be under a northwest flow aloft on the back side of a persistent vortex over Hudson Bay. This will result in a continued feed of cold Arctic air southwards into the region. Thursday and Friday will bring daytime highs successively colder at +4 and +2 °C respectively. Overnight lows should hover in the mid-minus single digits. Both Thursday and Friday will bring partly cloudy skies to the city and winds will gradually ease from around 30–40 km/h on Thursday to around 20 km/h on Friday. Other than the chance for some lake-effect rain showers or snow in the lee of the lakes — more likely Lake Winnipeg than Manitoba — conditions should stay dry.

Long Range Outlook

The long-range outlook shows nothing but a big vortex entrenched over Hudson Bay. As a result, it also shows nothing but seasonably cold weather for Manitoba. Forecasts show daytime highs locked at the low single digits and overnight lows hovering within a couple degrees of -5 °C.

NAEFS 8-14 Day Temperature Anomaly Forecast — Valid October 21-28, 2020
A stationary vortex over Hudson Bay will bring a prolonged period of cool temperatures to Manitoba. This NAEFS temperature outlook shows a high probability of seasonably cold weather over the province persisting into next week.

The cooler weather towards this coming weekend may end up producing lake-effect snow in the lee of Lake Manitoba in addition to Lake Winnipeg, particularly Friday night into Saturday.

Temperatures may begin to moderate towards seasonal values slightly next weekend (October 24–25), but confidence is low right now.

Today’s seasonal daytime high in Winnipeg is 11 °C while the seasonal overnight low is 0 °C.

Cooler Weather Ahead

Temperatures will slowly drop through the week in Winnipeg as a colder air mass gradually builds into the region.

Winnipeg will see just two more days of near-seasonal temperatures before a pattern shift ushers northerly winds and an Arctic air mass into the region. In the wake of yesterday’s rain, Winnipeg will see mainly sunny skies today. Winds will pick up out of the west to 30 gusting 50 km/h as temperatures climb to a high near 14 °C.

The winds will ease tonight as temperatures dip to around +3 °C. A passing disturbance will bring some cloud to the region overnight. A few showers are possible closer to the U.S. border, but Winnipeg should stay dry through the night.

On Tuesday, westerly winds will strengthen early in the day, up to as high as 40 gusting 60 km/h across the region. Temperatures will reach a near-seasonal high of 12 °C under sunny skies. The wind will quickly die off this evening followed by a low near +3 °C. Skies should gradually cloud over through the night ahead of the next low pressure system approaching the province.

RDPS 2m Temperature Forecast valid 21Z Wednesday October 14, 2020
Northerly winds will begin ushering cooler air into southern Manitoba on Wednesday.

On Wednesday, a low pressure system will dive across North Dakota into Minnesota. In Winnipeg, this system will bring cloudy skies with a chance of rain showers. Winds will also pick up out of the north to 30 gusting 50 km/h in the afternoon. These northerly winds will keep things cooler with a high of only 8 °C. The cloud cover will start to break up overnight as winds ease to northwesterly at 20 km/h and temperatures dip to a low of -3 °C.

Long Range Outlook

Colder weather continues to push southwards through the rest of the week under mixed to cloudy skies. Temperatures will top out near 5 °C on Thursday and drop towards 2–3 °C by the end of the weekend. Overnight lows will hover in the -2 to -5 °C range. A few rain showers (or snow flurries!) may be possible heading through the weekend.

Today’s seasonal daytime high in Winnipeg is 11 °C while the seasonal overnight low is +1 °C.

Mild Weather Continues

Winnipeg will continue to see seasonably mild and windy weather this weekend.

Temperatures will climb into the mid-teens quickly this morning, but a cold front passing midday will cap the high near 16 °C. Behind the front, breezy northwest winds up to 40 gusting 60 km/h will develop for the afternoon hours. Although the front will bring some clouds to the region, there will be plenty of sun through most of the day.

The winds will taper off this evening as a ridge of high pressure builds in from the north. Winnipeg should see a low near +1 °C with partly cloudy skies.

Temperatures will be a bit cooler on Saturday as the ridge leaves the region. Winnipeg will see mostly sunny skies with a near-seasonal high around 13 °C. Winds will pick up out of the south in the afternoon to 30 gusting 50 km/h and then increase to 40 gusting 60 km/h overnight. These southerly winds will bring a surge of warm air northwards and the city will see a mild overnight low 10 °C.

RDPS 2m Temperature Forecast valid 21Z Sunday October 11, 2020
The Red River Valley will see mild temperatures with daytime highs climbing into the low 20s on Sunday.

A low pressure system passing through on Sunday will bring mostly cloudy skies to the region for the day. Winds will continue out of the south at 30 to 40 km/h, continuing to tap into warmer air. This will send high temperatures to around 20 °C. There will be a little bit of instability in the region through the afternoon hours that may result in a few showers or thunderstorms. The chance is low in the Red River Valley and much more likely that the southeastern corner of the province.

Winds will shift to the southwest and ease to 20 km/h on Sunday night with mixed skies. Temperatures will still stay seasonably mild with a low near 8 °C.

Long Range Outlook

Temperatures will shift back towards seasonal values through the first half of next week. Many forecasts show cooler weather moving in for the second half of the week with daytime highs dipping into the 5–10 °C range. Dry weather is forecast to continue through much of the week.

Today’s seasonal daytime high in Winnipeg is 12 °C while the seasonal overnight low is 1 °C.

Warm, Dry Weather Ahead

Winnipeg will continue to see seasonably mild temperatures through the rest of the week along with plenty of sunshine.

If there’s a thing that can be said for Winnipeg in 2020 — considered by many to be a bit of a tire fire of a year — is that spring and summer have generally brought pleasant weather to spend time outside. And that seasonally pleasant outside weather continues after the brief cool snap last week!

Upper ridging will gradually spread across the Prairies through the rest of the week, bringing partly cloudy to mixed skies and highs of 15–20 °C. The subsidence associated with the upper ridge will also keep things nice and dry over southern Manitoba.

Lows will dip close to freezing tonight and the low single digits on Friday night. A weak low moving through the region on Thursday night will help keep temperatures warmer with a low near 8 or 9 °C.

RDPS 2m Temperature Forecast valid 21Z Friday October 9, 2020
Seasonably warm weather will return to Winnipeg on Friday.

If there’s any downside to things, it’s that it will be a bit breezy over the coming days. The city will see northwest winds up to 30 gusting 50 km/h today that ease this evening. On Thursday, a southerly flow will strengthen ahead of an approaching low into the 30–40 km/h range. Winds will ease Thursday night. On Friday, northwest winds of 30 gusting 50 km/h will redevelop behind the departing low.

Long Range Outlook

Temperatures will briefly dip to seasonal values on Saturday as an Arctic high glances through the region. On Sunday, warmer temperatures will quickly build back into southern Manitoba with highs near 20 °C possible. Clouds will spread in through the day with showers possible to start the work week on Monday.

Temperatures are then forecast to shift seasonably cool for the rest of the work week with conditions staying on the cloudier side.

Today’s seasonal daytime high in Winnipeg is 13 °C while the seasonal overnight low is 2 °C.