First A Frost, Then More Rain on the Way This Weekend

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The Red River Valley will see a frost on Saturday morning, then more rain is on the way for Sunday and Monday.

The sun returns today after another 10 to 20 mm of rain drenching in the Red River Valley. Winnipeg will see a seasonably cool high near 12°C as an Arctic ridge builds into the province. Winds will be light out of the northwest at 15 to 25 km/h. That Arctic ridge will bring frost to the region tonight with lows dropping to -1 or -2°C through the valley. Winds will be light overnight with a few clouds lingering.

Much of southern Manitoba will see frost tonight as temperatures drop below 0°C early Saturday morning.
Much of southern Manitoba will see frost tonight as temperatures drop below 0°C early Saturday morning.

That Arctic ridge will remain in place on Saturday, keeping winds light and temperatures cool. Winnipeg will see a high of 10°C with increasing cloud cover. The cloud will be thickening up ahead of a major fall storm that will impact the entirety of the southern Prairies. What will be a major snow storm for the Alberta Foothills will transition to a mix of rain and snow across Saskatchewan and to primarily a rain event for Manitoba. Rain will spread northwards through the Red River Valley on Saturday night with temperatures dipping to a low near +4°C. The wind will pick up overnight as well, increasing out of the northeast to 30 km/h by Sunday morning.

More rain is on the way for Manitoba on Sunday into Monday, but this fall storm will bring significant snow to portions of Saskatchewan and Alberta.
More rain is on the way for Manitoba on Sunday into Monday, but this fall storm will bring significant snow to portions of Saskatchewan and Alberta.

Southern Manitoba will see more wet weather on Sunday with periods of rain moving through the region. Winnipeg will see a cool high near 7°C with moderate northeasterly winds of 30 to 40 km/h through the day. Periods of rain will persist through Sunday night with temperatures remaining steady. Much of the region will likely see 15 to 25 mm of rain through Sunday to Monday morning.

Long Range Outlook

The Red River Valley will see more rain on Monday with another 10 to 20 mm possible. Rain will taper off Tuesday, but cool temperatures and a brisk northwest wind will likely result in some lake-effect precipitation. The rest of the week looks dry with below-normal temperatures.

If you have plans to travel west across the Prairies on Sunday through Tuesday, keep in mind that this system will bring significant snowfall to some areas in Saskatchewan into southern Alberta. Check ECCC’s forecasts for not only your destination but also stops along the way to ensure you don’t hit any unexpected winter driving conditions.

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

Unsettled Weather Leads Into Extended Cool Stretch

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Winnipeg will see a couple more chances of rain before the entire region plunges into an extended period of seasonably cool conditions.

A breezy day lies ahead for Winnipeg as an unstable northwest flow moves over the region. Winds will pick up to 30 gusting 50 km/h today as temperatures head to a near-seasonal high of 15°C. There should be plenty of sun this morning, but skies will become mixed as it warms up. The chance for a few scattered showers will develop for the afternoon. Winds will ease this evening with clearing skies. Temperatures will dip to a low near +4°C with more cloud cover pushing in early Thursday morning.

The next low pressure system to affect the region will approach through on Thursday, spreading more cloud cover in through the day. As a result, Winnipeg will see mostly cloudy skies for much of the day. The day will again see seasonal temperatures with a high near 16°C and west-southwest winds near 20 km/h. Unfortunately, it’s going to be the last day we see seasonal conditions for a while. By late in the day, rain will spread across the Red River Valley. Most regions will see several hours of wet weather that will taper off overnight. Temperatures will head to a low near 5°C with winds shifting to the northwest. Much of the Red River Valley looks to receive close to 10 mm of rain by Friday morning with local amounts up to about 20 mm possible.

Rain will spread across southern Manitoba on Thursday night with most areas seeing 10 to 20 mm by Friday morning.
Rain will spread across southern Manitoba on Thursday night with most areas seeing 10 to 20 mm by Friday morning.

Brisk northwest winds near 30 km/h will usher in a cooler, drier air mass on Friday. The cloud cover will break up early, leaving behind mixed skies for most of the day. Temperatures will be seasonably cool with a high of just 10°C. The region will see just a few clouds lingering on Friday night as the winds taper off. Temperatures will dip to a low near +1°C with a chance of frost.

Long Range Outlook

Cool weather will persist right through much of next week with daytime highs in the upper single digits for much of that time. Saturday should bring some sun to the area, but with northerly winds and cool temperatures the chance for lake-effect showers will develop.

An extensive push of colder than seasonal temperatures will develop this weekend, persisting through next week.
An extensive push of colder than seasonal temperatures will develop this weekend, persisting through next week.

Widespread unsettled conditions look to return with another disturbance lifting out of the United States for Sunday into Monday, potentially lingering into Tuesday. How far north the rain from that system will be able to push is still uncertain, however, and could end up falling just short of the Canadian border.

Today’s seasonal daytime high in Winnipeg is 16°C while the seasonal overnight low is 4°C.

Sunny Monday Gives Way to Unsettled and Cooler Conditions

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Winnipeg will see a sunny and mild Monday, but cooler weather and unsettled conditions return for the rest of the week.

A weak upper ridge will bring sunny skies and mild temperatures to Winnipeg today. Temperatures will climb to a high near 23°C this afternoon with southerly winds strengthening into the 20 to 30 km/h range. An approaching trough will bring increasing cloud tonight and keep the southerly winds up around 20 km/h. Winnipeg’s temperature will dip to a low near 13°C.

A digging upper-level trough will bring unsettled conditions to the region on Tuesday. With cloudy skies, showers will spread across the region from west to east through the day. More rain will certainly be a concern to waterlogged areas that saw 50 to 100 mm of rain last week; fortunately, this system doesn’t look too strong. Most areas will only see 4 to 8 mm through the day. Winnipeg may find itself on the northern edge of the rain; if so, the city could escape with just a couple mm.

Temperatures will be comparatively cool with a high near 16°C and light winds. Winds will gradually shift west-northwest through the night at 15 to 25 km/h. As they shift, the cooler air moving into the region will help generate lake-effect streamers. This will keep mixed to cloudy skies through the Red River Valley on Tuesday night with a continued chance of drizzle or showers. Temperatures in Winnipeg will dip to a low near 8°C.

More showers will move across southern Mantioba on Tuesday
More showers will move across southern Mantioba on Tuesday

Winnipeg will see mixed skies on Wednesday with northwest winds near 30 km/h. The chance for drizzle or showers will continue off the lakes, but become weaker and more isolated into the afternoon. Temperatures in the city will top out around 14°C. A ridge moving into the region will ease the winds on Wednesday night and send temperatures to a low near +3°C.

Long Range Outlook

Thursday will bring a short break from unsettled conditions as a ridge of high pressure moves through. Things quickly turn around for Friday, though, as another low pressure system moves across the southern Prairies. Another 5 to 15 mm look possible Friday afternoon through Saturday. Cooler weather will return for the end of the weekend with more lake-effect showers possible.

Today’s seasonal daytime high in Winnipeg is 16°C while the seasonal overnight low is 5°C.

Severe Thunderstorm Threat Returns to Southern Manitoba

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Winnipeg will see several rounds of thunderstorms over the next 36 hours, some of which may be severe.

A sharp long-wave trough moving into the region will produce several rounds of thunderstorms over the Red River Valley through the next 36 hours. The initial wave of thunderstorms is pushing through the Red River Valley already. These storms produced a variety of severe weather overnight as they moved through Saskatchewan and southwest Manitoba and will continue to pose a slight chance of producing severe hail or wind gusts.

A large mesoscale convective system developed over SE Saskatchewan into Manitoba on Thursday night and is bringing strong to severe thunderstorms to the Red River Valley this morning.

After those storms move through, Winnipeg should see mixed skies with temperatures increasing to a high near 25°C. Winds will be breezy out of the southeast at 30 gusting 50 km/h.

Another round of thunderstorms will develop later today, likely producing a swath of severe weather extending from the southwest corner of the province right through to Ontario. The storms will begin this afternoon over the southwestern corner of the province and then move through the Red River Valley through the evening. These thunderstorms will be capable of large hail, severe wind gusts, and torrential downpours causing flash flooding.1 It will be a complex and dynamic system this evening, so be sure to stay aware of any watches or warnings issued by ECCC later today.

Another line of strong to severe thunderstorms will move thorugh southern Manitoba later today.
Another line of strong to severe thunderstorms will move thorugh southern Manitoba later today.

Saturday morning will likely bring a brief reprieve before an upper low moves into the region. As it moves in, more showers and thunderstorms are forecast to develop. There will be less energy for the storms to utilize, but they may still produce some hail and rather heavy downpours.2 The unsettled conditions will keep things cool with a high near 20°C expected in Winnipeg. Winds will be light to start the day, but pick up out of the northwest late in the day. Temperatures will drop to a low near 12°C with a northwest wind of 20 to 30 km/h and a continued chance of showers on Saturday night.

Conditions will finally settle for Sunday. Skies will gradually clear out with a northwest wind of 20 to 30 km/h. Winnipeg can expect a high near 19°C. A ridge of high pressure will move in on Sunday night, bringing calm winds and a low near 6°C.

Long Range Outlook

Much of next week looks to bring variable cloudiness and warm to seasonal temperatures. By the end of the week, conditions may turn cloudier with a chance of showers.

Today’s seasonal daytime high in Winnipeg is 17°C while the seasonal overnight low is 5°C.

  1. MLCAPE values near 2000 J/kg combined with 35 knots of deep shear and a perpendicular warm front orientation should support squall-line structures with large hail and strong winds. PWAT values climbing to 50 mm will ensure that the thunderstorms produce heavy rain, and rapid accumulations with flash flooding is possible in any areas that see slower-moving or training thunderstorms. ↩
  2. MLCAPE values near 500 J/kg will combine with bulk shear values of 40 to 50 knots to produce widespread showers with embedded thunderstorms. PWAT values of 35 mm will support moderate to heavy rainfall rates. ↩