Category: Forecasts

Heat Returns, Along with a Risk of Thunderstorms

Scott 1 Comment

The heat will return early this week as temperatures climb up to the thirty degree mark. This warm and humid air mass will also bring another risk of thunderstorms to southern Manitoba on Tuesday.

Hot weather is in store for southern Manitoba early this week
Hot weather is in store for southern Manitoba early this week

This Week

Today will be a hot one in southern Manitoba. Temperatures are expected to climb into the low thirties in most areas. The humidity will begin to climb as well, with dewpoints reaching the upper teens in most areas by late Monday – although locally higher dewpoints will be possible. Despite these hot and humid conditions it doesn’t appear that we’ll see any storms today. The atmosphere is expected to be capped, preventing thunderstorms from developing. There is a slight risk of storms overnight, but conditions don’t look particularly good for widespread development.

Tuesday will be the more interesting day storm-wise, as humidity increases further. A low pressure system is expected to sit over southern Manitoba by midday Tuesday, maintaining a south to southeast surface flow over the Red River Valley and southeastern Manitoba. Instability will be high with the hot and humid conditions, while wind shear is also strong because of the approach of a strong upper-level trough. These conditions should be favourable for the development of severe thunderstorms. High temperatures should end up near 30C with the humidex in the upper thirties. Skies will be mainly sunny before storms begin to develop.

A strong cold front is expected to slice through southern Manitoba on Wednesday morning. This front will drop temperatures down to near the 20C mark. The front will also take advantage of the lingering humidity in the atmosphere to produce shower activity over most of southern Manitoba. Following the frontal passage, it will become quite gusty as well, with northerly winds of 40 km/h gusting to 60 km/h.

Long Range

It appears that temperatures will begin to rebound later this week following the passage of that cold front on Wednesday. Temperatures approaching the 30C mark may be possible again by the weekend – although models are still unclear as to how long and intense this next burst of heat will be.

Cool Weekend Offers A Break From Thunderstorms

Brad Leave a comment

The weather is taking an abrupt turn today as significantly cooler air moves into Southern Manitoba behind the low pressure system that brought numerous thunderstorms to Winnipeg & area on Wednesday night.

Today will see unseasonably cool temperatures as a high pressure system moving into Manitoba draws air from the Arctic and ushers it southwards into the province. The cool air, coupled with the August sun, will result in plenty of cloud and some scattered showers through the afternoon. With a northwesterly wind of 20-30 km/h, temperatures will climb to a high near 20°C.

Skies will remain fairly cloudy tonight as cool air continues to push southwards. For areas in the western Red River Valley, it appears that the Arctic air will trigger some lake-effect showers that will move southwards off of Lake Manitoba. There’s a lesser chance that similar showers will develop off of the south basin of Lake Winnipeg as well. Winnipeg will end up tucked between the two and should remain dry for much of the night. Expect overnight lows to dip down to around 8 or 9°C.

The bright green swath over the western RRV shows the expected lake-effect showers on Friday night.
The bright green swath over the western RRV shows the expected lake-effect showers on Friday night.

Saturday will be a drier day with the cool weather continuing. Daytime highs will climb to around the 19°C mark under mixed skies. Skies will clear out for Saturday night for another cool one with overnight lows near 8°C.

Sunday will return to closer to seasonal temperatures with highs near 24°C under mainly sunny skies. There will be a bit of cloud moving through later in the day as warmer air begins moving into the region, but no precipitation is expected in the Red River Valley with it at this point.

So, while it will be cooler, we’ll get a short break from the severe weather threat that has been so frequent the past few weeks across Southern Manitoba. Next week looks like a bit of a mixed bag with dry, warm weather through the first half of the week being replaced by cooler, more unsettled weather in the second half.

Winnipeg’s seasonal daytime high is currently 24°C while the seasonal overnight low is 11°C.

The Summer of Storms Continues

Brad Leave a comment

Whether you’re in the middle of a home renovation that involves taking off part of your roof as I am[1], trying to harvest fields, or just trying to string together a few dry days for a camping trip, this summer continues to challenge as the threat for thunderstorms continues across the Red River Valley.

Today will be a hot one across southern Manitoba as a light southerly wind taps into a warmer air mass to our south, drawing daytime highs up to around the 30°C mark in Winnipeg. Skies will be fairly sunny until late in the day when cloud cover begins thickening up from the west.

Estimated precipitation totals from the RDPS for Wednesday night through Thursday.
Estimated precipitation totals from the RDPS for Wednesday night through Thursday.

A cold front sweeping into Manitoba through the evening and overnight will once again spread showers and thunderstorms into Manitoba. There will be a slight risk of severe thunderstorms in the late afternoon and evening hours to the north and west of the Red River Valley. This severe thunderstorm threat will shift into the Red River Valley late in the evening & into the overnight period. These thunderstorms will pose a primary threat of large hail and damaging winds.

The unsettled activity will persist into Thursday morning with more showers and thunderstorms possible as the upper-level support for this disturbance rolls through. Winds will pick up out of the northwest to about 20 km/h as skies begin to clear for the afternoon. Temperatures will be a just slightly cooler with a high near 27°C, but the overnight low on Thursday night will be much cooler at around 13°C.

Friday will continue the cooling trend in temperatures as another cold front pushes through, limiting daytime highs to the low 20’s. Mixed skies will be in place alongside a slight chance of some afternoon showers and gusty north to northwesterly winds of 20-30 km/h.

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

  1. Anyone? Just me?  ↩

Warm With A Risk of Thunderstorms

Scott Leave a comment

This week will be a warm one, with temperatures frequently reaching the upper twenties. This heat will be accompanied by some humidity, which will prompt a renewed risk of thunderstorms.

A warm front will be located in southern Manitoba today
A warm front will be located in southern Manitoba today

This Week

Today will be a hot one in southern Manitoba. Temperatures will be in the upper twenties to near 30C, with increasing humidity making it feel more like the mid thirties. Winds will generally be light, with the direction varying between easterly and southerly depending on your location. The heat and humidity today will prompt a risk of thunderstorms. Some storms may be marginally severe, as moderate instability but weak wind shear characterizes the environment. Any severe storms could potentially produce hail around nickel size and wind gusts to 90 km/h – although the odd storm may slightly exceed those values. Storm coverage is not expected to be very widespread, so many people may not see any activity.

A weak cold front will pass through early Tuesday, cooling us down a little bit. High temperatures on Tuesday will generally be in the mid twenties, with some lingering humidity making it feel closer to 30. A risk of thunderstorms will once again be present due to that lingering humidity, but any storms that develop should be non-severe. Winds will be northerly at around 20 km/h.

Slightly warmer conditions are expected again for Wednesday as temperatures climb into the upper twenties with light southerly winds. Skies are expected to be mainly sunny, making for quite a nice day!

Long Range

The long range forecast shows a stronger cold front passing through southern Manitoba later this week, likely on Thursday or Friday. Depending on the timing of this front, it may pose another risk of thunderstorms. Following the frontal passage we’ll see somewhat cooler conditions, likely persisting into the weekend.