Warm Late-Summer Weather Continues

A persistent southerly flow over southern Manitoba will keep the seasonably warm and humid conditions in place for a for a few more days.

RDPS 2m Temperature Forecast valid 21Z Wednesday September 18, 2024
A stalled low over eastern Montana will continue to pump warmer air northwards into southern Manitoba this week.

A quick note to start: the lack of forecasts last week was due to the fact that I’m dealing with a long-lasting bout of COVID–19 that’s sidelined me for a while now. I’m on a [gradual] up and up now, with symptoms finally receding after testing positive on rapid tests for a whopping 11 days in a row. Not a fun time, looking forward to getting back at life.

Daytime highs in the mid-20s will continue into mid-week for the Winnipeg area as a persistent low pressure complex to the west supports a southerly flow across the region. Daytime highs for Tuesday and Wednesday will likely sit around 25 °C; it could be a touch cooler if a bit of a stronger cold pool is left behind from overnight convection, or a tad warmer if we clear out early and a stronger southerly flow can develop earlier in the day.

The humidity will also be notable for mid-September, with dew point values in the mid- to upper-teens, potentially reaching around 20 °C on Wednesday. This is more humid that the region often sees at this time of year, but the lower daytime highs in the 20s should keep the worst of the heat effects at bay. In the sun, the heat and humidity could combine to feel like it’s in the low 30s rather than mid-20s.

RDPS 2m Dew Point Temperature Forecast valid 21Z Wednesday September 18, 2024
In addition to the seasonably mild temperatures, it will continue to be humid across southern Manitoba.

Overnight lows both tonight and tomorrow night will sit in the mid-teens.

Weather-wise, today should bring clearing skies as the disturbance that brought rain and thunderstorms to the region yesterday pushes off to the east. A few clouds will begin to build back in tonight, leading to mixed skies on Wednesday as a cold front approaches the region from the west.

A few showers are possible on Wednesday; it looks like they should be weak, though the slow-moving nature of the cold front and broad forcing could result in a narrow band of slow-moving showers that could produce some locally higher amounts in the 15 to 25 mm range. I’m doubtful Wednesday will be a “wet” day, more likely a cloudier one with the chance of passing showers.

The cloudiness and chance of showers will continue into Wednesday night.

Unsettled End to the Work Week

The low that’s been sitting to the west all week will finally get moving on Thursday, moving into southwest Manitoba on Thursday and sliding into northern Manitoba on Friday.

This will bring a notable change in the weather to southern Manitoba. To start, both Thursday and Friday could bring wet conditions to the Red River Valley. On Thursday, showers and thunderstorms will begin possible through much of south-central and southeast Manitoba as the forcing along the cold front picks up with the advance of the low. This activity will likely continue into the night as it pushes northeast.

Winds will finally shift on Thursday from the persistent southerly at 20 to 30 gusting 50 km/h seen much of this week to westerly winds of 15 to 30 km/h.

On Friday, showers in the instability on the back-side of this system may clip through southern Manitoba as cooler air moves into the region. Daytime highs will cool into the low 20s by the end of the work week.

Long Range Outlook

Heading into the weekend, more settled conditions will develop over the region as near-seasonal temperatures return. Winnipeg will see partly cloudy conditions over the weekend with daytime highs in the upper teens and overnight lows near the 10 °C mark.

This trend looks to continue into the start of next week.

Today’s seasonal daytime high in Winnipeg is 18 °C while the seasonal overnight low is 6 °C.

Temperatures Warming Back up This Weekend

After a couple cooler and unsettled days, sunnier skies and warmer weather will build back into southern Manitoba this weekend.

RDPS 2m Temperature Forecast valid 21Z Saturday September 7, 2024
Significantly warmer temperatures will begin to spread east across the Prairies on Saturday.

To wrap up the work week, Winnipeg will start the day with mixed skies and a slight chance of showers. A weak disturbance over the region this morning will bring that chance of unsettled weather, but it will dissipate as the day wears on. Winnipeg will likely see mixed skies continue into the afternoon as temperatures climb to around 20 °C.

Temperatures will head to a low in the 5–10 °C range tonight with light winds and clear skies.

Heading into the weekend, an upper ridge will build across the Prairies, bringing heat back to the region. Southerly winds will increase into the 20–30 km/h range on Saturday with highs pushing back into the mid-20s. The city should see partly cloudy to mixed skies through much of Saturday, but no chance of rain.

Winds will ease on Saturday night as skies clear and temperatures head down into the low teens.

On Sunday, temperatures will climb back up into the upper 20s with light winds and sunny skies. It will cool down overnight back to the low teens again.

Long Range Outlook

The upper ridge will continue to pump heat into the region to start next week, sending daytime highs close to around 30 °C. Much of next week will bring seasonably hot conditions with highs mainly in the 25–30 °C range.

There’s little to no chance of rain until the second half of the week, but the most likely chance for rain will develop towards the weekend when the upper ridge begins to break down and cooler temperatures begin to push back into southern Manitoba.

Today’s seasonal daytime high in Winnipeg is 20 °C while the seasonal overnight low is 8 °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.