The heat will stick around for just one more day before a cold front ushers in cooler temperatures that will persist through the remainder of the week. That cold front will also bring the threat of severe thunderstorms to the Red River Valley this afternoon as it slides southeastwards through the region.

Today’s weather focus for Winnipeg & the Red River Valley will be the continued heat and humidity in place and the cold front that will be shunting it out today. Temperatures will rise quickly this morning towards a daytime high near 30-31°C. With dew points still in the 18-20°C range, humidex values will climb into the upper 30’s once again. By early afternoon, a cold front will start slumping southwards into the Red River Valley, bringing with it a risk for thunderstorms.

As shown in ECCC’s thunderstorm outlook, there is a chance for severe thunderstorms over the Red River Valley and southeastern Manitoba.

The primary threat with today’s thunderstorm will be large hail. As shown in ECCC’s outlook, hail up to 5 cm diameter — a bit larger than a golf ball — is possible in the worst storms that form today. Heavy rain will be the second threat as it’s quite likely the rainfall coming out of the line of storms is torrential. Whether or not there’s overland flooding will depend on how quickly the line is moving; at this point, it seems like things will be progressive enough that while the rain will be heavy, it won’t reach severe criteria (50 mm in under 1 hour). There may be strong winds in some of the storms, but it won’t be as common as large hail and heavy rain. There is not a significant tornado threat today.

The biggest uncertainty will be when exactly the thunderstorms start. If they form early, around 1PM or so, then they’ll initiate to the northwest of Winnipeg and move through the city early to mid-afternoon. Should the capping inversion hold longer and storms don’t form until 3-4PM, then it will be likely that the cold front has passed through Winnipeg and the storms fire to the south and southeast of the city. The southern Red River Valley and southeastern Manitoba have a high probability of seeing thunderstorms this afternoon.

Behind the cold front, winds shift out of the northwest to around 20 km/h as skies clear. Temperatures will drop to a low near 17°C tonight.

Tuesday will start off sunny with skies becoming mixed in the afternoon as a weak disturbance moves towards the region. Temperatures will climb to a high near 26°C, but the humidity will be much more comfortable as dew points fall to the 11-13°C range in the continued light northwesterly winds. There may be a slight chance of some isolated showers in the afternoon. Tuesday night will bring some clearing in the evening, but then more organized cloud will begin moving in ahead of a low that will impact the region on Wednesday. Temperatures will drop to around 11°C.

Wednesday will bring cloudy skies and a good chance of showers to Winnipeg and the Red River Valley. It will be a relatively cool day with highs around the 20°C mark and continued light northerly winds. The chance for showers will taper off in the evening with temperatures dropping to a low near 11°C.

Long Range

The remainder of the work week looks quiet with temperatures near-seasonal, if not a bit below. There may be some chances for showers on Friday or Saturday, but it’s still looking a bit unclear at this point.

Winnipeg’s seasonal daytime high is currently 26°C while the seasonal overnight low is 13°C.

Another disturbance tracking across the Prairies will bring more wet weather to Winnipeg and keep temperatures cooler than seasonal for late June.

Today will start off with a line of showers and/or thunderstorms moving eastwards through the Red River Valley as a cold front pushes eastwards across the region. General rainfall amounts within the Red River Valley from this system will be around the 5-10 mm mark, although locally higher amounts are possible in thunderstorms. That said, it’s likely that the eastern Red River Valley sees higher amounts while the western Red River Valley trends towards lower amounts. Depending on exactly how things have evolved overnight, though, there may be sizeable gaps in the line of precipitation resulting in some areas seeing no rain at all.

The wet and stormy weather will clear out of the valley midday, and Winnipeg will be left with gradually clearing skies into the evening. Temperatures will climb to high near 22°C this afternoon with winds picking up out of the northwest to 20-30 km/h behind the cold frontal passage.

Winnipeg should see fairly clear skies tonight with light winds as temperatures dip to a low near 13°C.

Thursday will likely begin with some sunshine, but quickly cloud up in the morning as another low pressure system begins moving into the area. Any wet weather should hold off until mid-to-late afternoon; heading towards evening it looks likely that another batch of scattered showers or thunderstorms will develop. With the wet weather holding off until later in the day, it will actually be relatively pleasant despite the cloudy skies with temperatures climbing to a high near 22°C and light winds.

Scattered showers will likely continue across the Red River Valley on Thursday night, supported by a cold low stalled over the region. Temperatures will head to a low near 14°C.

Friday will bring mainly cloudy skies and scattered showers or thundershowers to Winnipeg and the Red River Valley. Temperatures will be cooler as a cold low stalls over the region; daytime highs throughout the Red River Valley will be just 19-20°C. Winds will be light out of the north at 10-20 km/h.

Long Range

Canada’s 150th anniversary celebrations are looking okay at this point; cloudy skies in the morning should gradually clear through the day, although we may see a few light showers through the first half of the day. Temperatures will climb to a high near 21-22°C with winds out of the north at 10-20 km/h. For the evening celebrations, skies should be mixed or partly cloudy with temperatures somewhere in the 15-20°C range.

Sunday will be a pleasant day with partly cloudy skies and a high near 23°C. Heading into next week it looks like we’ll finally snap out of this cool spell and see some seasonal to above-seasonal temperatures build in for the week!

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.