Cooler, Cloudier Start To The Week, Then Warming Up

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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

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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. ↩

 

Winnipeg Continues To See Hot Summer Conditions

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After an unsettled start early Wednesday morning, Winnipeg will see plenty of sunshine and hot weather for the remainder of the work week.

Winnipeg will see a generally unsettled morning today as a low pressure system rolls into Manitoba. The bulk of it will have occurred with the convective complex that has moved through the city early this morning, but a few more showers are possible along a cold front moving through later today. Before that happens, hot and muggy conditions will develop under mixed skies; temperatures will climb to a high near 32°C with dew points near 20°C. This will result in humidex values in the upper 30s. Once the cold front moves through, any lingering chance for showers will taper off, skies will clear, and drier air will begin working into the region from the west. Winnipeg will see a mild low near 19°C tonight under clear skies.

Winnipeg will see hot and humid conditions before a cold front pushes through Wednesday afternoon.

The next two days will bring more beautiful summer weather to the city as a ridge of high pressure builds in. Winnipeg will see mainly sunny skies both Thursday and Friday with daytime highs near the 30°C mark. Conditions won’t be too humid, and both days will see westerly winds; Thursday should see stronger winds in the 30 to 40 km/h range while lighter winds near 20 km/h move in for Friday. Lows will continue to be mild in the 17 to 20°C range.

Long Range Outlook

More warm weather is on tap for Saturday with daytime highs once again climbing above 30°C. A strong cold front passing through on Saturday night looks to bring a risk of thunderstorms to the region, followed by the arrival of a more seasonal air mass. The start of next week looks to bring plenty of sun, daytime highs in the 23 to 27°C range, and overnight lows in low to mid-teens.

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

 

Hot Summer Weather Continues

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A pleasant few summer days lie ahead for Winnipeg with plenty of sunshine and temperatures climbing towards the 30°C mark. A low pressure system passing through on Wednesday will bring breezy winds, muggy conditions, and a chance of showers to the Red River Valley.

Winnipeg will kick off the week with a pristine summer day as a ridge of high pressure moves through the region. Temperatures will climb to a high near 29°C under sunny skies and light winds. The heat will be comfortable thanks to low humidity values. Temperatures will dip to a low near 16°C under mainly clear skies tonight.

Temperatures will climb back towards the 30°C mark in Winnipeg on Tuesday.

Tuesday will bring partly cloudy skies to the region with a southerly flow redeveloping. There’s a small chance of a shower early in the morning in Winnipeg, but most guidance suggests that the rain will pass to the southwest of the Red River Valley. Otherwise, it will be a warm day with a high near 30°C. Winds will pick up out of the southeast to 20 to 30 km/h.

The next low pressure system crossing the Prairies will begin to impact southern Manitoba on Tuesday night. With a chance of showers or thunderstorms, it will spread cloud into southern Manitoba along muggier conditions. Winnipeg will see a mild low near 21°C as winds increase out of the south to 30 to 40 km/h.

Fairly muggy conditions will return to the Red River Valley on Wednesday, however it won’t be as extreme as experienced this past Saturday.

Much of the rain with this low is forecast to spread north of the Red River Valley into the Interlake on Wednesday. That said, Winnipeg and areas south will see a chance of showers on Wednesday morning as a cold front sweeps eastwards through the region. Once it clears midday, the breezy southerly winds will shift to westerly near 30 gusting 50 km/h. Winnipeg will see a high near 30°C again.

Skies should remain clear on Wednesday night with a low near 19°C.

Long Range Outlook

The remainder of the week continues to look warm with highs near 29 or 30°C and comfortable humidity levels. Both Thursday and Friday look to bring mainly sunny skies to Winnipeg.

Unsettled weather is forecast to return Friday night into Saturday as the next low pressure system moves through the region, bringing another chance of thunderstorms to the Red River Valley.

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