Cooler Weather Settles In

Just like that, fall weather has arrived in the Red River Valley with temperatures over 10 °C cooler than seen on the weekend.

RDPS 2m Temperature Forecast valid 12Z Friday October 4, 2024
The first freeze of the season could arrive by Friday morning.

Today marks the start of fall weather in southern Manitoba, courtesy a much cooler air mass brought in by yesterday’s cold front and very gusty winds. This change reflects a major shift in the large-scale weather pattern; the upper ridge over the Prairies has collapsed, and a quasi-stationary upper low is becoming established over the western coast of Hudson Bay. This change will result in a more west to northwest flow aloft over Manitoba, ushering in seasonal conditions for this time of year.

The result will be a week filled with daytime highs in the mid-teens and overnight lows dropping into the 0 to 5 °C range with a risk that we may see the first frosts of the season.

For a bit more detail, today will bring cloudier conditions with lighter winds than yesterday. A high pressure system passing to the south will spread southwest winds of 20 to 30 km/h into the region as temperatures climb into the mid-teens. A weak disturbance slumping southeastwards across the Prairies will keep conditions cloudy tonight; this will ensure that the overnight low stays mild (for this week) at around 10 °C.

Another cold front will sweep through on Wednesday, bringing gusty northwesterlies and cooler temperatures back to the region. With the cooler temperatures moving in and the prolonged northwesterly flow, some lake-effect showers may develop. Winds will likely keep these north of Winnipeg, but worth noting the possibility for areas in the northern Red River Valley.

A ridge of high pressure will push into the province behind the front, bringing clearing skies and sending overnight lows to near-freezing for the rest of the work week. A widespread freeze could be possible over southern Manitoba overnight Thursday into Friday morning.

Long Range Outlook

A moderating trend will develop over the weekend across southern Manitoba with daytime highs heading back towards the upper teens. Overnight lows will also follow the warming trend, likely heading back into the 5–10 °C range through the weekend.

The region will see variable cloudiness, but little to no precipitation is expected.

Today’s seasonal daytime high in Winnipeg is 15 °C while the seasonal overnight low is +3 °C.

Warm Early Fall Weather Continues Through the Weekend

Warm and sunny weather will remain in place across southern Manitoba this weekend.

RDPS 2m Temperature Forecast valid 21Z Sunday September 29, 2024
A low pressure system moving into Saskatchewan will bring very warm weather to southern Manitoba on Sunday.

A southwesterly flow aloft will sit over the southern Prairies this weekend and continue to push warm air into the region. With the storm track shunted northwards of the region, Winnipeg and area will see sunny skies that last right through the weekend.

Daytime highs will climb from the low 20s today into the mid- to upper-20s this weekend. Overnight lows will hover around 10 °C tonight and tomorrow, but a push of warmer air on Sunday night will keep lows warmer in the mid-teens.

Winds today will be light, eventually picking up out of the south into the 15 to 25 km/h range this afternoon. A weak high pressure system moving through on Saturday will bring light northerly winds to the region. On Sunday, the wind will pick up quite a bit with the push of warmer air moving into the region. Southerly winds will strengthen as high as 50 gusting 70 km/h midday and persist through much of the night before beginning to ease.

All in all, aside from the winds on Sunday, it looks like it’s going to be a beautiful few days ahead.

Long Range Outlook

A low pressure system will cross the province on Monday, bringing a significant pattern change to southern Manitoba. This system will bring showers to the region as a cold front sweeps across the province. In its wake, cooler weather will slump southwards out of the Arctic. This will result in breezy northwest winds, daytime highs slumping into the 10 to 15 °C range, and the chance of some lake-effect showers through the first half of the week.

While there may be a couple blips of warmer weather later in the week, it looks like this marks a shift back towards near-seasonal temperatures for the region for a while.

Today’s seasonal daytime high in Winnipeg is 15 °C while the seasonal overnight low is 4 °C.

Hot Weather Before a Big Cool-Down

There will be a couple more hot days in Winnipeg before a cold front sweeps through the province and ushers in much cooler conditions for a few days.

RDPS 2m Temperature Forecast valid 21Z Tuesday September 3, 2024
Southern Manitoba will have another couple days of warm weather before a strong cold front pushes through the region.

A weak upper ridge building east across the Prairies will bring warm weather to southern Manitoba over the next couple days. In Winnipeg, temperatures will climb to a sunny high near 30 °C today and into the mid-20s on Wednesday. Southerly winds of 30–40 km/h will build into the region today and ease into the 20–30 km/h range tonight. Temperatures will dip down to an overnight low in the upper teens tonight.

A trough of low pressure will move through on Wednesday morning, bringing mixed skies and lighter winds. Skies will clear through the day with northwest winds up to 30 km/h developing for the afternoon. There may end up being a low chance of isolated afternoon showers or thunderstorms, but it does not look likely right now.

A more substantial pattern change will occur on Wednesday night, marked by a strong cold front that pushes into the region overnight. This will bring northerly winds up to 40 gusting 60 km/h to the region as a colder air mass moves in. The cold front will bring a chance of showers to the region on Wednesday night into Thursday morning. Temperatures will head to a low in the low teens on Wednesday night.

Much cooler conditions will move into the region on Thursday, marked by an Arctic high building across the Prairies. Temperatures will struggle back to the mid-teens on Thursday with cloud cover breaking up through the day.

Temperatures will head down into the mid-single digits on Thursday night with clearing skies and easing winds.

Long Range Outlook

Friday will bring more cool weather to the region with sunny skies and a high in the upper teens. It iwll be another cool night with lows in the mid-single digits on Friday

Light southerly winds will redevelop on the weekend, marking the start of a gradual trend towards warmer weather. By next week, the region will be back to daytime highs in the mid- to upper 20s and overnight lows in the low teens.

Today’s seasonal daytime high in Winnipeg is 21 °C while the seasonal overnight low is 9 °C.

Weather Settling Through the Weekend in Southern Manitoba

Seasonal temperatures will return to southern Manitoba as a ridge of high pressure begins to build into the region from the west.

RDPS 10m Wind Forecast valid 21Z Saturday August 31, 2024
A passing disturbance will usher in moderate northwest winds across southern Manitoba on Saturday.

Warmer temperatures return to Winnipeg and area today as westerly winds continue across the region. Daytime highs will climb back into the mid-20s today as warmer weather bounces back into the region behind the low that moved through yesterday. The wind will be persistent out of the west today near 30 gusting 50 km/h, then ease in the evening. The entire region will see plenty of sunshine today.

The low tonight will dip down into the low teens.

On Saturday, an upper-level disturbance will rotate through the region, bringing mixed skies to the region and a chance of showers. The rain looks to mainly stay north of Winnipeg with decreasing likelihood further south. As the disturbance passes through, it will usher in moderate northwest winds up to 40 gusting 60 km/h across the Red River Valley. This will keep daytime highs near-seasonal in the low 20s.

There is a chance with both the tail end of the westerlies today and the northwesterlies on Saturday that smoke may move into the Red River Valley. It’s unclear how thick any of those smoke plumes would be, though it looks more likely that Saturday would bring a more noticeable smoke plume into the region for a time.

The winds will taper off on Saturday evening with clearing skies and an overnight low that dips into the upper single digits.

A broad ridge of high pressure will move across southern Manitoba on Sunday, bringing light winds, clear skies, and seasonal highs in the low 20s.

Long Range Outlook

A southerly flow will redevelop early next week and bring warmer weather back into the region with highs climbing back into the upper 20s. It does not look like there will be an appreciable chance of rain in the first half of the week, but the chance for mid-week thunderstorms can’t be ruled out at this point.

Enjoy the weekend!

Today’s seasonal daytime high in Winnipeg is 22 °C while the seasonal overnight low is 10 °C.