After a rainy weekend we’ll have a chance to dry out this week as skies clear. Temperatures will be cool, but generally near seasonal values.
Cool and windy conditions are expected on Monday in southern Manitoba
This Week
Today will see mainly sunny skies as the low pressure system from the weekend moves off to the east. However, it will remain quite windy behind the system with northwesterly winds of 40 km/h gusting to 60 km/h. Temperatures will sit in the mid teens over most of southern Manitoba. There will be a slight risk of frost in low-lying areas tonight as temperatures drop rapidly with the light northwesterly flow.
Tuesday will see slightly improved weather over today as winds calm down and temperatures climb up into the mid teens. Skies will also remain mainly sunny, making for a generally pleasant day.
Wednesday should be one of the warmest days this week. Temperatures are expected to climb up near the 20C mark under light southerly winds and mainly sunny skies.
Long Range
Long range models hint at another strong low pressure system developing to our west later this week. It remains unclear if and when this system may affect us, but it likely won’t be until the weekend at the earliest. The good news is that this system will draw up a warm, southerly flow, perhaps giving us a brief stretch of warm weather before it arrives.
After a relatively benign week, unsettled weather is set to return this weekend as a slow-moving upper trough brings several waves of rainfall through the region.
Today will be the most pleasant of the next few, we see relatively pleasant temperatures for the latter portion of September under mixed to cloudy skies. The cloud is courtesy a large weather disturbance moving into the region driven by a strong upper-level trough1 developing over much of western North America.
Winnipeg will see increasing cloud through the day as easterly winds pick up to around 20 km/h and temperatures climb to around 17°C. As the evening progresses, the entire Red River Valley will see an increasing chance of rain as precipitation lifts northeastwards with the warm front of this system. Precipitation amounts will likely be in the 5-15 mm range with this first wave, although if heavier convective pockets form, localized amounts of 15-25 mm may be possible.
A deep upper-level trough is developing over western North America, and is forecast to extend from the northern tip of Yukon Territory all the way to the southern New Mexico border by Saturday morning.
Saturday morning will start with overcast skies with the chance of drizzle throughout much of the Red River Valley. Winds will be out of the southeast at 20-30 km/h with relatively warm temperatures—a high near 22°C is expected–but the main weather story will be a cold front pushing from the southwest to the northeast through the afternoon and evening. As it lifts northeastwards, a large band of rain is expected to develop along it and give another 5-15 mm in about a 3-6 hour window. Here in the Red River Valley I expect it to move through early Saturday night, but with complex systems like these, its possible that timing could change by 4-6 hours either way. We’ll keep an eye on it as things develop.
A cold front will push across Southern Manitoba on Saturday as a large low pressure system lifts to the northeast.
The cloud will likely break up a bit on Saturday night as winds taper off a bit and temperatures head to a low near 12°C.
We won’t be free from the clutches of this system on Sunday either. There’s a chance we have a nice start to the day with some sunshine, but things will quickly cloud up as a fair amount of wrap-around cloud and showers move in from the north behind this low pressure system. For areas that see rain, amounts should be fairly light with accumulations more in the 2-5 mm range, but will be accompanied by brisk northwesterly winds and a high near 17°C. The scattered showers will likely hang round through the overnight period as temperatures head down to a low near 10°C.
Summary
It won’t rain non-stop all weekend. It appears that the rain will come through 3 waves: first on Friday evening/night, then on Saturday afternoon/evening, and then on Sunday sometime midday to the evening and persisting until Monday morning. Rainfall totals will vary, but guidance suggests the heaviest rainfall will occur in Saskatchewan, clipping through Parkland Manitoba with over 50 mm possible.
Here in the Red River Valley, there may end up being a strong discrepancy of rainfall accumulation based on location, but in general totals of 10-30 mm seem possible at this point.
It’s worth noting that relatively minor variations in track of this particular system could result in significant shifts in how much rain we’ll see, so updates will be provided if needed as the weekend rolls on.
Long Range
After we escape the clutches of this system on Monday morning, conditions look fairly good through the remainder of the week. At this point, it appears Winnipeg will see near-seasonal highs in the mid- to upper-teens and overnight lows dipping just below 10°C through much of the week. Not a lot of cloud is expected, and winds look to to be fairly light. So a bit of a crummy weekend, but we’ll be making up for it with a stretch of pleasant fall weather!
An upper-level trough is a feature in the upper atmosphere that is evident via a large dip southwards in the jet stream. ↩
Cloudier conditions will be on tap for Winnipeg & the Red River Valley through the remainder of the work week, however with little precipitation expected and seasonal to slightly above seasonal temperatures, conditions will be fairly pleasant.
Skies will be mixed to cloudy across Winnipeg & the Red River Valley today as a complex disturbance in the United States spreads cloud across much of the Southern Prairies. A chance of showers exists along the American border, but further north the chance drops off quite quickly. Winds will be fairly light as temperatures climb to a high near 18°C. Heading through tonight, skies will be partly cloudy to mixed as temperatures drop to a low near 7°C.
With the jet stream riding across the southern Prairies, southern Manitoba will see cloudier conditions with a chance for some shower activity near the American border.
Thursday will likely start with partly cloudy skies, but see more cloud cover move in through midday. Temperatures top out near 18°C with fairly light winds. Expect cloudy conditions on Thursday night as temperatures dip to around 8°C.
Friday is a bit of a wildcard at this point, but it appears that morning cloud will give way to some afternoon sun before more cloud cover moves into the region on Friday night. Temperatures will top out near 19°C with winds out of the east at 20-30 km/h.
Friday night will bring cloudy skies with a good chance of rain as a more organized area of rain moves from southern Saskatchewan and southwestern Manitoba into the Red River Valley.
Long Range
The weekend is looking quite unsettled and wet with rain likely both Saturday and Sunday as a slow moving upper-low moves towards the region. At this point, it looks like there may be a significant convective element to this system, meaning that rainfall amounts could be highly variable across the region. Daytime highs will continue to sit near 17°C through the weekend with overnight lows in the low teens.
Winnipeg’s seasonal daytime high is currently 17°C while the seasonal overnight low is 5°C.
Fall-like weather will move into Manitoba this week as moderate westerly winds behind a cold front that moved through yesterday usher out any notion of humidity and bring cool nights back to the region.
Today will be a mild day with a high near 21°C in the Red River Valley, but beneath sunny skies will be a moderate westerly winds of 40 gusting to 60 km/h. Expect to see a few less leaves on some of the trees when the day is done.
Strong westerly winds (shown by purples and pinks) will develop over southern Manitoba today.
Winds will taper off this evening as the temperature heads to a low near 9°C under clear skies.
Tuesday will be another mainly sunny day courtesy a ridge of high pressure moving into the region. Winds may pick up to 20-30 km/h in the morning, but will then taper off in the afternoon as the main ridge axis moves into the Red River Valley. Temperatures will climb once again to a high near 21°C.
Temperatures will head to a low near 10°C on Tuesday night with increasing cloudiness as a low pressure system begins to organize south of the border.
Wednesday will bring mixed to mostly cloudy skies to Winnipeg & the Red River Valley. There will be a chance for some light rain near the International border as this weather system grazes along the 49th parallel, but little accumulation is expected at this point. Winds will be out of the north at 15-25 km/h and temperatures will climb to a cooler high of 17 or 18°C.
Expect skies to clear on Wednesday night as temperatures head to a low near 8°C.
Long Range
A fairly strong low pressure system is forecast to develop in the second half of the week, but general consensus at the moment is that it will remain the United States’ problem, leaving us to wrap up the second half of the work week with partly cloudy skies and seasonal highs in the mid-teens. As we head into the weekend, the chance for rain will re-emerge as the weather turns a little more unsettled. At this point, it doesn’t appear that any widespread or major rainfalls are expected.
Winnipeg’s seasonal daytime high is currently 17°C while the seasonal overnight low is 5°C.
