Improving to Start The Weekend, Unsettled Weather Returns On Sunday

Winnipeg will see a mixed bag over the next few days with showers tapering off early Friday morning, a pleasant Saturday, then followed by unsettled weather on Sunday.

Today will start cloudy with a chance of showers, but a ridge of high pressure building into the region will bring gradual clearing to Winnipeg through the afternoon. Temperatures will reach a high near 25°C, but the wind will be a breezy out of the north-northeast near 30 km/h. The wind will taper off early this evening, then skies will clear as temperatures head to a low near 14°C.

Saturday will be a beautiful day in Winnipeg & the Red River Valley. The ridge of high pressure will bring sunny skies and light winds to the region as highs climb to around 28°C. Humidity levels will be comfortable. A few clouds will move in overnight as winds pick up a bit out of the southeast. Winnipeg should see a low near 16°C on Saturday night.

RDPS 2m Temperature Forecast valid 18Z Saturday July 21, 2018
A ridge of high pressure will be in place over southern Manitoba on Saturday, but the next low pressure system to impact the region will already be spreading across Saskatchewan.

A warm front will push through early Sunday, bringing some cloud cover to the region. There’s a small chance of a shower as overnight activity from Saskatchewan and southwestern Manitoba dies off. The remainder of the day will bring mixed skies alongside gradually increasing humidity. Winnipeg should see a high near 28°C. The threat for thunderstorms will return through the afternoon as a cold front pushes eastwards across the province.

Long Range Outlook

Next week looks to bring seasonal to slightly below-seasonal temperatures to the region and variable cloudiness. There are no major signals for precipitation, so expect generally dry weather and comfortable humidity through much of the week.

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

 

Mid-Week Heat Breaks with Unsettled Conditions on Thursday Afternoon

The heat is on today as highs soar into the low 30’s across many parts of southern Manitoba. It will be short-lived, though, as a cold front passing through on Thursday brings unsettled conditions and seasonal temperatures back to the region.

Temperatures will soar today as a significantly warmer air mass moves into the region. Winnipeg will see a high temperature near 32°C today; fortunately humidity levels will be comfortable and humidex won’t be an issue. Winds will be relatively light out of the south at only around 20 to 25 km/h.

Temperatures will be mild tonight with a low in Winnipeg near 19°C. Humidity levels will increase overnight with conditions beginning to feel a bit muggy by Thursday morning.

Thursday will be a warm and humid day in Winnipeg. Temperatures will climb to a high near 28°C with light southerly winds. It appears the low pressure system we mentioned on Monday will stay south of the border, but several upper features, followed by a weak cold front moving through in the afternoon will trigger scattered showers and thunderstorms. The potential for organized severe weather appears low, but isolated severe thunderstorms may be possible with large hail and/or wind the primary concern. Northwesterly winds of 20 to 30 km/h will develop in the evening as the cold front passes, then diminish to light overnight. Temperatures will be a bit cooler on Thursday night with a low near 16°C expected in Winnipeg under mostly cloudy skies.

RDPS 12hr. QPF valid 00Z Friday July 20, 2018
Scattered showers and/or thunderstorms will be possible across southern Manitoba on Thurday

Friday will start with lingering cloud cover, then see gradual clearing alongside diminishing humidity as the day progresses. Winds will be breezy out of the north at 30 gusting to 50 km/h. Winnipeg will see a high near 26°C followed by a low near 15°C under clear skies on Wednesday night.

Long Range Outlook

That ridge of high pressure will bring pleasant, seasonal conditions to Winnipeg on Saturday. Sunday looks to bring more cloud to the region ahead of the next low pressure system crossing the Prairies. Later in the day on Sunday, the chance for [thunder]showers increases as the low approaches the province.

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

 

Cooler, Cloudier Start To The Week, Then Warming Up

Winnipeg will see below-seasonal temperatures on Monday, then rebound back towards a summer sizzler mid-week with daytime highs potentially climbing above 30°C.

Winnipeg will see markedly cooler temperatures today as a ridge of high pressure builds into the region behind the cold front that moved through southern Manitoba on Saturday night. Daytime high of just 20°C will be the coolest Winnipeg has seen since June 4th when the temperature topped out at 19.7°C. The city will see some cloudy periods, but rain isn’t a concern. Winds will continue out of the northwest at 20 to 30 km/h through the day, then diminish early this evening. Under clearing skies Winnipeg will see a low near 9°C tonight.

RDSP 2m Temperature Forecast valid 21Z Monday July 16, 2018
Significantly cooler temperatures will be in place across Manitoba today with daytime highs generally in the 15 to 20°C range.

Tuesday and Wednesday will light southerly winds as a return flow develops over southern Manitoba. Warmer temperatures will build back into the province into the middle of the week. Tuesday will see a high near 26°C, then more summer sizzle arrives on Wednesday with a high near 30°C. Skies will remain sunny on Tuesday, but Wednesday will see mixed to cloudier skies develop in the afternoon. Overnight lows will climb as the warmer air moves into the province. Lows will fall into the mid-teens on Tuesday night followed by a very mild low near 20°C on Wednesday night.

Fortunately, humidity levels will remain comfortable for the next 3 days. Muggier conditions are forecast to redevelop on Wednesday night as a more humid air mass spreads out of the Dakotas. At the moment, it doesn’t look too bad with dew points in the upper teens expected. Humidity becomes significantly more oppressive once the dew point exceeds 20°C.

Long Range Outlook

Wednesday night into Thursday morning will bring a renewed thunderstorm risk to the region. A low pressure system is forecast to move through the Dakotas and may end up moving northwards into southern Manitoba. If it does so, it will likely support an area of elevated convection on Wednesday night, then generally unsettled weather on Thursday. If the low ends up remaining south of the border, southern Manitoba should still see a fair amount of cloud, but much less rainfall.

Cloudier weather will likely stick around for part of Friday as well, then a cold front swings through and ushers in drier conditions. Temperatures should remain warm through the end of the week with daytime highs in the upper twenties and lows in the mid- to upper teens.

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

 

 

 

Summer Scorcher Gives Way to Seasonal Conditions

A heat warning is in effect for Winnipeg with another two days of sweltering, increasingly humid, weather on the way. A cold front will move through Saturday evening, though, bringing a risk of thunderstorms and a return to seasonal temperatures.

Winnipeg will see daytime highs well over 30°C both today and tomorrow as an upper level ridge moves through. Temperatures will climb to a high near 32°C today under sunny skies. Winds will increase out of the west-northwest from light this morning into the 20-30 km/h range this afternoon. Winds will diminish to light tonight as temperatures dip to a low near 19°C. Saturday will be a scorcher. Southerly winds will strengthen to 40 gusting 60 km/h and draw a more humid air mass northwards. With highs expected to reach 34 or 35°C alongside dew points in the upper teens, Winnipeg will see another day with humidex near 40.

A sharp cold front will surge southeastwards through the Red River Valley on Saturday evening.
A sharp cold front will surge southeastwards through the Red River Valley on Saturday evening.

A sharp cold front sweeping southeastwards will bring a moderate threat of severe thunderstorms to the Red River Valley late Saturday afternoon into the evening. Going over the MIST ingredients:

  • Moisture: While surface moisture will likely be plentiful, it won’t be particularly deep. The southerly wind should help sustain moisture transport, though, with deeper moisture near the cold front likely as it pools.
  • Instability: With high surface moisture, SBCAPE values are impressive with over 3500 J/kg forecast. However, MLCAPE values will likely be substantially less in the 1000 to 2000 J/kg range as the moisture drops off with elevation.
  • Shear: Shear is moderate with 25 to 35 kt of 0-6 km bulk shear forecast. As storms progress into the evening, 20 to 30 kt of effective shear is forecast.
  • Trigger: Strong convergence along a cold front sweeping southeastwards.

The most likely scenario at this point looks like scattered thunderstorms will develop along the cold front in the late afternoon, stretching from the southern Interlake into southwestern Manitoba. These storms will push southeastwards into the Red River Valley, but timing will be important; winds are forecast to weaken aloft as the evening progresses, likely meaning that these thunderstorms will weaken as the evening progresses. The primary threat these storms will pose will be damaging hail and/or winds. The tornado threat looks low right now.1

Winds will shift north-westerly behind the cold front at 15 to 25 km/h as temperatures head to a low near 15°C.

Sunday will be a relatively pleasant day in Winnipeg. Temperatures will climb to a seasonal high near 25°C under partly cloudy skies, but winds will strengthen out of the west to around 30 gusting 50 km/h. Winds will ease on Sunday night with a low near 14°C.

Long Range Outlook

Winnipeg will see plenty of sunshine to kick off next week with slightly below-seasonal to seasonal temperatures. Warmer weather returns mid-week as an upper ridge builds back into the eastern Prairies. Unfortunately, rainfall remains elusive. No widespread relief is on the way for agricultural regions beginning to experience heat and moisture stress.

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

  1. If surface winds back a little more than currently forecast, tornadoes may be a threat with these thunderstorms, primarily through the late afternoon and early evening.