A Weather Moment

Southern Manitoba will see a mix of weather this week with more rain on Thursday.

The region will get a bit of a chance to dry out today, a welcome change after the 15–25 mm of rain seen across most of the region yesterday. Sunnier skies will send highs near 20 °C, but it will be windy this afternoon. Southwest winds will pick up into the 40–50 km/h range this afternoon.

The winds will taper off this evening as a ridge moves across the region. Lows will dip into the upper single digits. More cloud will push into the region early Wednesday morning as a push of warmer air begins moving in aloft from the Dakotas.

Wednesday will bring cloudy skies to the region with a chance of showers a warm front slowly continues northwards towards southern Manitoba. Temperatures should climb into the upper teens with northeast winds picking up to 20–30 km/h through the afternoon. A few sunny breaks might materialize later in the day, but skies will cloud back over in the evening.

The next storm system to impact the region will begin its approach on Thursday night. It will spread showers and thunderstorms into the Dakotas as it moves northwards, reaching the Manitoba border by Thursday morning. A broad area of rain will move through the region on Thursday, bringing another 15–30 mm of rain to the Red River Valley. A few embedded thunderstorms will be possible and could result in locally higher rainfall accumulations. A more organized thunderstorm threat will develop late in the day, but will highly likely be for southeastern Manitoba into MN/ND. The rain will taper off by Thursday evening with just a few lingering showers hanging around until Friday morning. Temperatures will sit in the mid-teens on Thursday with breezy northeast winds.

Some sunshine will poke through later on Friday with temperatures climbing back towards the 20 °C mark. Moderate southwesterlies will develop through the day, climbing into the 40–50 km/h range.

Long Range Outlook

Cooler temperatures will build into the region for the weekend in the wake of this next storm system. Highs will fall into the 10–15 °C range with mixed skies over the weekend. Warmer weather will begin building back into the region near the middle of next week. Fortunately, it doesn’t look like any frost is in the forecast; overnight lows should drop only to the mid-single digits.

Today’s seasonal daytime high in Winnipeg is 18 °C while the seasonal overnight low is 4 °C.

Temperatures will stay mild in Winnipeg through the weekend, but sunshine will give way to more chances for showers.

Warmer weather will continue to push into the Red River Valley over the coming days. Daytime highs will stay in teh 20s, reaching close to the mid-20s on Saturday. This push of warmer weather is thanks to a stubborn low pressure system over the northern Prairies. It will support a southerly flow over the southeastern Prairies, drawing a consistent stream of milder air northwards. With that, though, will also come several disturbances that will also move north in the flow.

After a plenty of sunshine day today, a broken line of showers will push across the Red River Valley. Supported only by a weakening trowal, the showers won’t likely amount to much. Skies will clear out overnight as temperatures dip into the low teens.

Saturday will be a slightly more interesting weather day across the region. Off to a sunny start, the day will warm up quickly. Winnipeg should reach 20 °C by noon, and climb close to 25 °C in the afternoon. Of note will be that it will become quite windy in the afternoon with strong southerly winds of 50–60 km/h. This will be particularly concerning as the winds will generate significant wave action on the flood waters through the valley. This will produce stress on flooded roads and flood barriers in place; consult local EMOs on whether you might need to take any additional action to reinforce any personal flood protection structures.

Later in the day, cloud will push into the region as a low pressure system lifts from eastern Montana into western Manitoba. This low will support an area of rain that moves through southeast Saskatchewan into western Manitoba through the day.

For our region, showers will likely develop late in the day as a cold front starts pushing eastwards towards the Red River Valley. By evening, the forcing of the cold front will combine with a strengthening low-level jet, triggering a line of showers and thunderstorms. The storm environment is even relatively supportive for this time of year. As long as the forecasted moisture advection from the American Plains is able to materialize, the storms will have a moderate amount of energy to work with and ample wind shear to organize it.

The storms will likely trigger close to the Saskatchewan border, then move east-southeast. Some of these storms may be severe with the potential for damaging hail and strong wind gusts. As the line approaches the Red River Valley, it will dig into the low-level jet, developing southwards. As a result, the storms in Manitoba will weaken as they head into the Red River Valley, making it more likely that our area sees some collapsing showers or weak thundershowers, although stronger storms could linger closer to the U.S. border.

Temperatures will drop down to around 10 °C on Saturday night. Showers will be possible through the night.

On Sunday, the region could see some morning showers but its highly dependent on the evolution of this system. The rest of the day will bring mixed skies to the region as we sit on the edge of a system passing to the east. Temperatures will still be mild with highs in the upper teens.

Long Range Outlook

On Monday, another disturbance will move into the province bringing more showers and a risk of thunderstorms to the region. After that, a couple nice days are in store, then another chance of showers or thunderstorms will develop later in the week.

Today’s seasonal daytime high in Winnipeg is 17 °C while the seasonal overnight low is 3 °C.