Showers and Smoke Today, Pleasant Week Afterwards

Winnipeg will see morning showers and widespread smoke today as a low pressure system passes by the region. Much more pleasant weather will return for the rest of the week and the start of school.

ECMWF 6-hour Precipitation Accumulation Forecast valid 18Z Tuesday September 5, 2023ECMWF 2m Temperature Forecast valid 18Z Tuesday September 5, 2023
Some lingering [thunder]showers will push off into Ontario on Tuesday morning, leaving behind a relatively cool day with highs near the 20 °C mark across southern Manitoba.

After the night’s heavier rain, a few showers or thunderstorms will drift northeastwards early this morning, clearing out of the Red River Valley as a low pressure system moves into Ontario. In its wake, widespread smoke will linger through much of southern Manitoba. This will give very poor air quality to the region and has resulted in a special air quality statement from the MSC. Winnipeg will likely see mainly cloudy skies today, though some late-day sun is possible. It will be a cool day, though, contrasting with the weekend heat as the daytime high only climbs to around 20 °C. Breezy northerly winds will abate this evening as skies clear. Temperatures will head down to a low near 10 °C.

Heading into the rest of the week, a steady and relatively stable pattern develops for the Winnipeg area. With a generally zonal flow aloft and disturbances tracking well to the north, conditions will trend fairly sunny throughout the Red River Valley. Smoke may be noticeable on a couple days through the rest of the week, but it’s unlikely to get anywhere near as bad as Tuesday’s conditions. And temperature-wise, there’s no complaints for the rest of the week with near-seasonal values expected. Highs will sit in the low 20s with lows dipping into the upper single digits.

Long Range Outlook

It currently looks like more of the same in the Red River Valley for the weekend and start of next week. Smoke will be the only wildcard in the long-range forecast, so we’ll keep our eyes peeled in case the potential for another bout of poor air quality arises.

After today’s smokey weather clears out, enjoy the beautiful late-summer weather!

Today’s seasonal daytime high in Winnipeg is 21 °C while the seasonal overnight low is 8 °C.

Seasonal Temperatures With Unsettled Conditions

Winnipeg will see seasonal temperatures in the mid-20s this week, but several passing disturbances will bring chances of showers or thunderstorms to the region.

RDPS 24-hour Precipitation Accumulation Forecast valid 12Z Wednesday August 23, 2023
Most of the organized shower activity on Tuesday will spread across the central Prairies, but a few showers are also possible further south in southern Manitoba.

Today will be another cooler day in Winnipeg as easterly winds undercut moisture streaming over the province in the upper-level flow. The city will see easterly winds around the 20 km/h mark much of the day. Skies will likely be cloudy through the day, but a few sunny breaks are possible in the Red River Valley and southeast corner of the province. North of the city in the Interlake, showers are likely through much of the day, while further south the best chances will be early in the morning, then again in the late afternoon. A few thundershowers may be embedded within these showers.

The showers will taper off this evening as the winds diminish and temperatures head to a low in the mid-teens. Skies will stay mainly cloudy overnight as the next disturbance approaches the region.

On Wednesday will be another cloudy day in Winnipeg. Showers and/or thunderstorms will likely push into the southwest corner of the province early in the day, then gradually spread eastwards through the day. By mid-afternoon, the chance of showers or thunderstorms will begin to increase in the Red River Valley. This activity will slump southeastwards through the evening and exit the province overnight. Temperatures will head down to a low in the upper teens on Wednesday night.

On Thursday, a bit of sun will return to the region, but cloud will push back in later in the day as another disturbance pushes towards the region from Alberta. More showers or thunderstorms will develop near the Saskatchewan/Manitoba border late in the day and then gradually spread eastwards through the evening. This will bring a chance of thunderstorms or showers to Winnipeg overnight, with a slight chance of showers lingering into Friday morning. The city will see the overnight low dip down into the mid-teens.

Regarding daytime highs, much of the week will bring near-seasonal highs in the low to mid-20s.

Long Range Outlook

Heading into the weekend, an upper ridge will begin to re-establish itself over the Prairies, bringing more settled conditions. Sunnier weather looks likely for the weekend with daytime highs climbing towards the upper 20s.

Today’s seasonal daytime high in Winnipeg is 24 °C while the seasonal overnight low is 11 °C.

Cool, Showery Weekend Ahead

An upper low crossing the Prairies this weekend will keep temperatures cool in southern Manitoba with some showers or thunderstorms likely in the days ahead.

RDPS 12-hour Precipitation Accumulation valid 00Z Saturday August 12, 2023
Rainfall will be scattered throughout southern Manitoba today as showers and thunderstorms develop over the region.

A weak low pressure system will move across southern Manitoba today, the lingering feature from the system that brought 5 to 10 mm of rain to Winnipeg yesterday evening. As this low trundles into the Red River Valley this afternoon, it will support the development of scattered showers and thunderstorms. Severe weather is unlikely; energy will be limited with only 500 to 1000 J/kg of MLCAPE and bulk shear is also low at only around 15 to 20 knots. A marginally severe thunderstorm with large hail can’t be ruled out, but much of the area will mainly see the chance of showers and shorter-lived pulse thunderstorms.

Much of the activity will taper off in the evening, but a few showers may linger into the night, supported by both a shortwave sliding across the region and a weak trough extending from southern Manitoba northwestwards into central Saskatchewan.

On Saturday, the region will continue to see mixed skies with a slight chance of showers. Much less activity is expected than on Friday; there will be few, if any, features to support and organize showers. A bit of lingering instability may be left behind, but for the most part, mixed skies with just a slight chance of an isolated shower or two is most likely.

On Sunday, another low pressure system is poised to dive southeastwards through the province, bringing a good chance of rain to many parts of southern Manitoba. Some uncertainty remains on the track, but in general areas south of a line that runs roughly from Dauphin to the Whiteshell are likely to see accumulating rain at some point from early Sunday morning through the end of the day.

Temperatures over the next three days will be steady in the 20 to 25 °C while winds will generally be on the lighter side. Winds both today and tomorrow will mainly be westerly, while the passing low will shift the winds more northerly on Sunday.

Long-Range Outlook

It’s looking like unsettled conditions will continue into next week. Monday should bring a reprieve from any wet weather, but the chance of rain will return several times through the rest of the week. Winnipeg’s daytime highs and lows will sit at near-seasonal values through next week.

Today’s seasonal daytime high in Winnipeg is 26 °C while the seasonal overnight low is 12 °C.

Heat Builds in for the Weekend

An upper ridge building into the eastern Prairies will bring hot conditions to southern Manitoba this weekend.

RDPS 2m Temperature Forecast valid 21Z Sunday July 2, 2023RDPS 2m Dew Point Temperature Forecast valid 21Z Sunday July 2, 2023
Sunday will bring the warmest weather of the next few days as hot temperatures and high humidity build into the region.

Seasonably warm conditions will build into southern Manitoba over the next few days with daytime highs climbing towards the 30 °C mark. In Winnipeg, today will bring mainly sunny skies that give way to some cloud in the afternoon while a ridge of high pressure brings sunny skies for Saturday.

Temperatures both days will climb into the upper 20s. Humidity levels will be comfortable in the mid- teens both days. For those heading out to enjoy Canada Day ???????? on Saturday, it will be a beautiful day to spend time outdoors!

On Sunday, the heat will really arrive as temperatures climb into the low 30s with increasing humidity. By the late afternoon, dew point values could reach as high as 20 °C, which would make it feel more like the upper 30s.

On Sunday afternoon, a warm-sector trough — typically an area of lower pressure near the middle of a large area of warmer air — will begin pushing across southern Manitoba. This feature will be an area of concern for severe thunderstorm development later on Sunday.

The thunderstorm potential will be significant on Sunday thanks to ample heat and humidity at the surface and relatively cool temperatures aloft. MLCAPE values could exceed 2,000 J/kg in an environment with 20 to 30 knots of 0–6 km bulk shear. Veering wind profiles would support supercell structures, but moderate westerly forcing along the line would likely support upscale growth into the evening hours. Capping will be marginal — 700 mb temperatures are forecast to be around 9 °C — so there is uncertainty with where the southern end of the line would develop. Wind profiles aren’t overly backed at the surface, so this setup wouldn’t likely produce a widespread tornado threat. If a thunderstorm was able to tap into all the available energy, though, an isolated tornado threat could develop. More likely, these thunderstorms would be capable of severe hail and torrential rainfall.

The details of this could change between now and Sunday, but at this point it looks like Sunday will be the hottest day of the next few and bring an organized severe weather risk to the region for late in the day.

Long Range Outlook

A weak cold front will push through Sunday night easing the humidity across the region.

Through the start of next week, temperatures should sit closer to seasonal values with variable cloudiness as cooler air moves in under a slow-moving upper trough that moves into the region. Some showers could be possible, but right now it looks like the start of the week will be mostly dry for Winnipeg.

Today’s seasonal daytime high in Winnipeg is 25 °C while the seasonal overnight low is 13 °C.