A complicated series of weather disturbances pushing across Southern Manitoba will provide a sensitive forecasting challenge as multiple batches of narrow bands of rain with sharp edges push across the Red River Valley and areas east.
Friday
17°C / 9°C
Mainly cloudy. Chance of showers.
Today will bring the most disorganized batch of precipitation as a weak low pressure system pushes out of ND/MN into the Lake of the Woods area. This seemingly weak feature will be coupled with a 500mb jet streak that will advect across the Red River Valley and the Whiteshell.
The upper-level jet streak will advect over a quasi-stationary front aligned north-south over the the Red River Valley. The convergence along the front, when combined with the lift associated with the jet streak, will likely produce some isolated showers and starting midday and lasting through the evening hours. The showers will be tied very tightly to the jet, so depending on where that jet ends up exactly will dictate where the potential lies. If things shift east slightly, the showers could easily only happen over SE Manitoba (in the Sprague area) or we could even see no showers at all.
It seems fairly likely there will be some isolated to scattered showers, though. With mainly cloudy skies the temperatures will struggle to warm up and we’ll likely see a high of only – and perhaps this isn’t all that bad since it’s close to seasonal for this time of year – around 17°C. Winds won’t be much of an issue today.
We’ll see plenty of cloud tonight alongside that chance for showers in the evening with temperatures dipping to around 9 or 10°C.
Saturday
15°C / 5°C
Cloudy. Slight chance of rain.
Saturday will be another rain event for Southern Manitoba as the upper trough that has been bringing the unsettled weather to the Prairies over the last week finally begins pushing eastwards. A low pressure will eject out of the upper trough on Friday night and rapidly lift northwards towards the Lake of the Woods and intensify. Rain will push into southeastern Manitoba on Friday night with a sharp western edge as the rain stays tightly associated with a strong upper-level jet. There’s some uncertainty on exactly where this jet is going to set up and how it will move through the day; some models keep the entirety of the rain over the SE RRV and Sprague/the Whiteshell while other models dig the upper trough a little more and pull the jet westwards, backing the rain into Winnipeg.
At this point, it seems like there are two rainfall scenarios for Winnipeg:
- The rain advects into Southern Manitoba further west than currently forecast and Winnipeg sees some rain (potentially somewhat heavy) early Saturday morning before it pulls off to our east and sits over SE Manitoba for the rest of the day.
- The main band of rain remains east of Winnipeg with us potentially seeing some light shower activity through the day as we get brushed by the edge of the system. Light winds and ample moisture may result in some on-and-off drizzle through the day.
While there is a chance that the main rain band may back further west and we’ll see a rainy day, I don’t think that outcome is very likely. It will be a cool, damp day with a high of only around 14 or 15°C. Clouds will clear out in the evening/overnight period as we drop to around 5°C for a low.
Sunday & Beyond
22°C / 10°C
Mainly sunny & warming up.
Sunday will bring much more pleasant weather as we see mainly sunny skies and a high in the low–20’s. It will mark the beginning of another stretch of fairly sunny weather with well above-seasonal daytime highs. We’ll see a low of around 10°C on Sunday night with clear skies.
The start of next week will bring sunny skies and temperatures climbing into the mid–20’s, as much as 10–11°C above the seasonal daytime high of around 14–15°C for this time of year!
