Winnipeg will see seasonal temperatures this weekend with generally cloudy conditions. Unfortunately, it looks like more rain may be on the way for Canada Day evening.
Any last showers or thunderstorms will push east of Winnipeg this morning, but plenty of cloud will remain as a trough lingers through the region. Winds will pick up out of the northeast to 20 to 30 km/h this morning while temperatures climb to a high near 23°C. Winnipeg will have mostly cloudy skies tonight as temperatures dip to a low near 15°C. The wind will ease tonight as it shifts northerly.
Cloudy skies continue Saturday with just a slight chance of showers. Winnipeg should see a high near 24°C with the sun peeking from the clouds a bit late in the afternoon. Winds will be out of the northwest at 15 to 20 km/h. Skies will cloud over again on Sunday night with a low near 14°C.
Unfortunately, more rain may be on the way in the evening on Canada Day
On Canada Day looks to bring a mixed bag to the city. After what looks to be a cloudy start, Winnipeg should see clearing skies for the afternoon with plenty of sunshine as temperatures climb to a high near 25°C. Winds shouldn’t be much of an issue either, increasing out of the southwest to around 15 to 25 km/h in the afternoon. Unfortunately, current guidance suggests that a low pressure system moving into the region will cloud things over again late in the day and bring showers and/or thunderstorms back to the region, possibly making outdoor celebrations a little unpleasant in the evening. The showers are forecast to exit the region overnight as temperatures dip to a low near 14°C.
Long Range Outlook
Next week is starting to look like it will be quite an unsettled one. Forecasts show an increasingly hot and humid air mass pushing northwards into the region. A couple organized systems are forecast to bring showers and the risk of thunderstorms to the region during the first half of the week.
Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 13°C.
A developing low pressure system in North Dakota will generate a widespread thunderstorm threat this evening and overnight that extends into southern Manitoba.
In North Dakota, there’s very high confidence that there will be some truly dangerous thunderstorms later today. A confluence of all severe weather parameters – extremely high amounts of energy, favourable wind profiles with high amounts of shear, a clear and potent focus for thunderstorm development – has led the SPC in the United States to issue a “moderate risk” thunderstorm hazard for the state today. Further north, things become a little more unclear and conditional in southern Manitoba.
The overall synoptic setup is summarized succinctly in the PASPC’s daily significant weather discussion:
[…] approaching long wave upper trough creating favourable synoptic setup tonight/overnight for a developing Colorado Low convective complex. This begins as a rapidly deepening baroclinic surface low in the Northern States with associated associated severe surface-based convection beginning this afternoon or evening.
So a rapidly deepening Colorado Low-type system will develop severe thunderstorms over North Dakota this afternoon. Continuing:
[As the convection] evolves and severe elevated convection becomes dominant through the night. Big question is where does [it] go? Details vary widely amongst model solutions, with some bringing severe convection clipping SE Saskatchewan then moving through southern Manitoba, and others confining the bulk of the severe weather to the United States.
And that is the big question. Where will the thunderstorms develop tonight? Here’s our thoughts, omitting much talk about what will happen in North Dakota.
The primary focus for thunderstorm development tonight in southern Manitoba will be split between two features. The first will be a warm front draped west to east along the Canada/US border for much of the night before lifting a bit further north over southeastern Manitoba late overnight. The second will be a mid-level shortwave that moves across southern Manitoba late overnight into Friday morning.
These two features will support independent areas of thunderstorm activity, then merge into a single area as the shortwave moves over the warm front.
A few isolated showers or non-severe thunderstorms are possible along and north of the warm front late this afternoon across northern North Dakota and far southern Manitoba. A more organized area of thunderstorms will develop over western North Dakota this evening and become the focus for thunderstorm activity for the following 12 hours. The thunderstorms will develop into a QLCS – quasi-linear convective system – mid-evening and accelerate eastwards. The mid-level shortwave moving into the region will draw moisture northwards from the QLCS across the border into southern Manitoba, supporting an area of showers and thunderstorms into southern Manitoba.
This activity will develop over the southwestern corner of the province sometime between 9 and 11 PM, then spread into the Red River Valley overnight.
AWM Thunderstorm Outlook valid 6PM Thursday June 28 to 6AM Friday June 29, 2018
Much of the severe weather in this scenario will be confined to North Dakota. There would be a slight risk of a severe thunderstorm south of the Trans-Canada Highway in Manitoba with primary threats of overland flooding due to heavy rainfall and large hail.
The convection will clear out overnight or early Friday.
Plan B
The alternative solution is one where the QLCS developing in North Dakota ends up surging eastwards, breaking away from the mid-level shortwave and becoming its own entity as it races towards Minnesota. In this case, less thunderstorm activity would be seen around the mid-level shortwave as it pushes into Manitoba overnight, however the organized southerly flow riding over the warm front would be undisturbed, likely allowing elevated thunderstorms to fire up overnight across far southern Manitoba. These thunderstorms, were they to form, would be more scattered in nature, but would pose a marked hail threat alongside torrential rains.
Not As Bad As It Looked Just 12 Hours Ago
In the end, the situation doesn’t look quite as bad over Manitoba as it did earlier this morning. If our expected solution pans out, most areas should just see a decent soaking with 15 to 30 mm of rain. Localized higher amounts will be possible, particularly closer to the US border. If the hail stays away, then we could be getting up tomorrow in the wake of a much-needed rainfall.
That said, if Plan B is what happens, or a hybrid of our expected solution and Plan B, then residents will need to prepare for the potential for large hail and localized flooding. We’ll be keeping an eye on things and likely issue one last brief update on our social media accounts later this evening.
Winnipeg will see a 36 hour reprieve before another low pressure system works into the region, bringing back the chance for showers and thunderstorms.
Sunny skies and seasonably mild temperatures will be in place for Winnipeg today as a weak ridge of high pressure moves through in the wake of the cold front that brought a few showers and thunderstorms to the Red River Valley last night. Winnipeg will see a high near 25°C with a light northwesterly wind at 15 to 25 km/h. Additionally, dew point values will plummet once it warms up a bit this morning, eliminating any feeling of it being humid outside. Skies will remain mainly clear tonight as temperatures drop to a low near 15°C with light winds.
Thursday will kick off with sunny skies and temperatures quickly warming into the mid-20s. Skies will become mixed in the afternoon as a warmer, increasingly humid air mass works into the region. Winnipeg should see a high near 28 or 29°C. Winds will be out of the south at 15 to 25 km/h.
A few showers are possible Thursday evening, but the larger focus will be a low pressure system moving through the Dakotas. As it moves eastwards overnight, it will likely develop a broad region of thunderstorms across the Dakotas and Southern Manitoba. These thunderstorms will spread eastwards across the province overnight, bringing with a chance of severe weather. Temperatures will remain warm on Thursday night as it gets increasingly humid; Winnipeg should see a low near 18°C.
Numerous forecasts show an extensive area of nocturnal thunderstorms developing across southern Manitoba and North Dakota on Thursday night
Friday will bring generally unsettled weather to Winnipeg and the Red River Valley. Temperatures will remain warm with a high near 25°C under mostly cloudy skies. There will likely be a few sunny breaks here and there, but they’ll just allow things to heat up enough to produce a chance of scattered showers or thunderstorms across the region. Winds will be out of the north at 10 to 20 km/h. Skies will clear out by evening, then Winnipeg will head to a low near 16°C.
Long Range Outlook
Looking ahead to the weekend, early indications are that Winnipeg will see variable cloudiness with a chance for more showers. Winnipeg is forecast to see near-seasonal highs in the mid-20s and slightly mild overnight lows in the mid-teens.
Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.
Winnipeg will continue to see unsettled conditions as a relatively humid airmass builds into the region.
Cloudy skies move into Winnipeg this morning as an upper-level disturbance drifts northwards in the southerly flow that has developed over the region. As it pushes into the Red River Valley, there will be a chance of showers alongside noticeably increasing humidity. The potential for rain will come in two waves: the first will be early this morning, then a second chance will develop this evening. There is a slight chance that there may be some thunderstorms in the second batch, but no significant threat exists for Winnipeg. Temperatures will be cooler than seen lately with a high near 24°C. Winds will be a bit breezy out of the southeast at 20 to 30 km/h.
Skies will become mixed overnight with a low near 18°C and winds continuing out of the south at near 20 km/h.
Tuesday will bring yet another chance for showers or thunderstorms, but not before the city experiences a hot summery day. Partly cloudy skies in the morning will become mixed in the afternoon as daytime heating begins producing more cloud cover. Temperatures will climb to a warm 29 or 30°C, but with the humidity it will feel closer to the mid-30s. Winds will once again be out of the south at 20 to 30 km/h. In the evening, a cold front will sweep through the Red River Valley.
A cold front sweeping eastwards across Manitoba will bring the chance of showers and thunderstorms to Winnipeg on Tuesday evening
This cold front will bring the threat of severe weather to southwestern Manitoba, but at this point it’s unclear as to exactly how the evolution of any thunderstorms will progress as they move into the valley and the evening. Winnipeg will likely see a good chance of showers or thunderstorms, and there may be a small chance for severe thunderstorm activity continuing along the cold front into the evening.
The cold front will push its way through the Red River Valley overnight as temperatures drop to a low near 16°C. Once the front passes, drier will begin moving into the region and skies will start to clear out.
Wednesday will be a beautiful summer day in Winnipeg: a high near 26°C, comfortable humidity, a bit of a northwesterly breeze, and plenty of sunshine. Skies look clear on Wednesday night as temperatures dip to a low near 16°C.
Long Range Outlook
The unsettled weather isn’t gone for long, though. Another low pressure system moving into the Dakotas will bring warmer and seasonably humid conditions back to Winnipeg on Thursday.
More showers and thunderstorms are possible Thursday night as another low pressure system moves into the region
On Thursday night, early forecasts are showing a good potential for thunderstorm activity across much of southern Manitoba with the low-level jet associated with the developing low pressure system supporting an area of nocturnal convection. Friday rounds out the work week with mostly cloudy skies and more chances for showers as another disturbance rolls through the region.
Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.
