Seasonal Conditions Return

Winnipeg will continue to see pleasant weather through the second half of the week. A few showers are possible Thursday afternoon into Friday morning as a weak low pressure system moves through the region.

A ridge of high pressure over the region today will ensure that Winnipeg sees mainly sunny skies through the day. Temperatures will continue at slightly below-seasonal values with a high near 19°C. The lack of wind and ample sunshine should help it still feel rather nice outside, though. Winds will remain light tonight with temperatures dipping to a low near 8°C under clear skies.

Thursday will start off sunny, but a weak warm front moving into the region in the afternoon will bring more cloud and a chance of showers. Winds will pick up out of the south-south-west into the 20 to 30 km/h range, pushing temperatures temperatures to a seasonal high near 23°C. A low pressure system will move through the region overnight, keeping cloudy skies with a chance of showers around through the night. Temperatures should dip to a low near 11°C with light winds.

Friday should start off with a few showers exiting the region, then a bit more sun returning. Temperatures will climb to a high again near 23°C with a northerly wind near 20 km/h. Winnipeg will likely see partly cloudy skies on Friday night with a low near 10°C.

Long Range Outlook

The weekend should bring Winnipeg near-seasonal temperatures and variable cloudiness. Winnipeg won’t likely see any significant chances of rain until sometime early next week. Forecasts show a more unsettled pattern developing over the region, bringing slightly warmer temperatures alongside plenty of cloud and a chance of precipitation.

Today’s seasonal daytime high in Winnipeg is 23°C while the seasonal overnight low is 10°C.

Hot & Windy Saturday Brings Thunderstorm Threat

Today will be a scorcher over southern Manitoba as strong southerly wind pump hot and increasingly humid air northwards. With that heat, though, will come a fair amount of instability and one of the first widespread severe thunderstorm threats of the season.

To start the day, some elevated convection will move across the region, most likely through the Interlake. These thunderstorms may be strong to severe, but should remain north of the Red River Valley. Although the storms should pass north of Winnipeg, the city will still see some passing cloud as they move by. These storms and their cloud cover should clear out by midday. As the sun comes out, the wind will pick up. A tight pressure gradient over the region1 will produce southerly winds up to 50 gusting 70 km/h today, helping heat and moisture surge northwards out of the United States. With those strong winds in place, Winnipeg will see temperatures climb to a high near 33°C. It will also get a tad more humid as the day goes on as dew points rise into the mid-teens.

Strong southelry winds will be in place over southern Mantioba this afternoon. To the west, a trough of low pressure extending southwards into the United States may trigger a line of thunderstorms late in the day.
Strong southelry winds will be in place over southern Mantioba this afternoon. To the west, a trough of low pressure extending southwards into the United States may trigger a line of thunderstorms late in the day.

By late in the afternoon, the thunderstorm threat will begin to build. A trough of low pressure over southwestern Manitoba into the Interlake may trigger the development of thunderstorms. If they develop, they’ll likely be strong to severe with primary threats of large hail and strong winds. Any of these thunderstorms that develop will move eastwards towards the Red River Valley through the evening. The focus then turns southwards to the Dakotas. A shortwave lifting northeastwards through the state will trigger convection late in the day. These thunderstorms will grow upscale and expand in coverage overnight. As the evening progresses, this blossoming area of thunderstorms will gradually spread across southern Manitoba. The potential for strong to severe thunderstorms exists tonight, with large hail and damaging wind gusts the primary threats. The thunderstorms should be through the Red River Valley by Saturday morning.

Temperatures will remain mild on Friday night with a low near 19°C. Those strong southerly winds will ease into the 20 to 30 km/h range this evening and then diminish to light overnight.

If thunderstorms are able to develop along the trough, southern Manitoba may see a line of thunderstorms marching towards the Red River Valley early in the evening.
If thunderstorms are able to develop along the trough, southern Manitoba may see a line of thunderstorms marching towards the Red River Valley early in the evening.

Saturday will bring plenty of cloud to Winnipeg as the low pressure system responsible for all this heat and instability moves through. Temperatures will be much cooler with morning temperatures near 18°C dropping to 14°C through the day. Winds will gradually pick up out of west into the 20 to 30 km/h range. More showers with the risk of thunderstorms are likely to develop later in the morning and persist through much of the afternoon. Conditions will calm down on Saturday night with some clear breaks developing towards Sunday morning. Winnipeg should see a low temperature near 9°C.

Sunday will bring seasonably cool conditions to Winnipeg, but things will get a chance to dry out. The city should see a high near 19°C under partly cloudy skies. Westerly winds near 30 km/h will be in place for much of the afternoon before diminishing in the evening. Winnipeg will see a low near 8°C with just a few clouds on Sunday night.

Long Range Outlook

Next week will bring seasonably cool temperatures with daytime highs around 20°C and overnight lows close to 10°C. The city will see variable cloudiness through the week, and a couple of passing disturbances may bring a chance or two of showers through the week. Temperatures should begin to warm up near the end of the week, but that may bring a return to unsettled conditions.

Today’s seasonal daytime high in Winnipeg is 23°C while the seasonal overnight low is 10°C.

  1. The tight pressure gradient is a result of a 996 mb low over western Manitoba squishing against a ridge of high pressure extending through SE Minnesota into Iowa.

More Warmth and Sunshine Ahead; Unsettled Weather Returns At End of Week

Warm weather continues in Winnipeg for a couple more days, but unsettled conditions will develop on Friday into the weekend.

Winnipeg will see mainly sunny skies today with temperatures climbing to a seasonably mild 26°C. Winds will be light for much of the day, then increase out of the south to around 20 km/h as a low pressure system approaches. The city will see a few clouds through the evening with a marginal chance of a passing shower or thunderstorm. It looks unlikely that Winnipeg will see anything, but the potential is there. Temperatures will head to a low near 12°C overnight with clearing skies.

Thursday will be a gorgeous day across the region as the upper ridge begins building in. Temperatures will climb to a high near 26°C under sunny skies with light easterly winds. The wind will pick up overnight into the 20 to 30 km/h range out of the southeast as a developing low pressure system strengthens over Saskatchewan. These breezy winds will help keep temperatures warm with a low of just 16°C expected. By early Friday morning, some cloud will spread into the region along with a chance of a thunderstorm.

Very warm temperatures will move into southern Manitoba on Friday.
Very warm temperatures will move into southern Manitoba on Friday.

For Friday, a high-amplitude trough-ridge pattern over the Prairies will drive the weather. This upper flow will result in the gradual strengthening of a slow-moving low pressure system near the Saskatchewan/Manitoba border. For Winnipeg, that means a breezy southerly flow tapping into hot air mass over the northern Plains. With winds in the 30 to 40 km/h range, temperatures will climb to a high near 30°C under a mix of sun and cloud. The city may see a chance for a thunderstorm early in the day, then the chance redevelops for Friday night. Temperatures will stay warm on Friday night, dropping only to around 20°C with southerly winds continuing.

Long Range Outlook

Early indications show a rather unsettled weekend for Winnipeg. Friday’s low near the SK/MB border will stall over the province, bringing several chances for rain or thunderstorms to the city through the weekend. The weekend will start warm, but should cool towards seasonal temperatures for Sunday. Next week looks to bring settled conditions with near-seasonal temperatures.

Today’s seasonal daytime high in Winnipeg is 22°C while the seasonal overnight low is 9°C.

Summer Arrives

Summer finally arrives in Winnipeg this week with seasonal to above-seasonal temperatures in place right through the week.

An approaching low will spread heat and southerly winds of 20 to 30 km/h through the region. Much of the day will bring partly cloudy skies to the city as temperatures soar to a high near 29°C. Notably different from other warmth so far this year will be the humidity; by the afternoon, dew points will climb into the mid-teens. While it won’t feel humid per-say, it will be a noticeable difference from when temperatures reached 30°C last Thursday. The chance for thunderstorms will develop mid- to late afternoon and persist overnight as the low pressure centre approaches. Temperatures will stay warm on Tuesday night with a low near 18°C.

Daytime highs on Monday will climb into the upper 20s and low 30s across much of south-central and southwest Manitoba.
Daytime highs on Monday will climb into the upper 20s and low 30s across much of south-central and southwest Manitoba.

The low will move through the Red River Valley on Tuesday morning, bringing mixed skies northwesterly winds. By midday, the city will be under mixed to mainly sunny skies with northerly winds near 30 gusting 50 km/h. These northerly winds will clear the skies and usher in a drier air mass the afternoon. Temperatures should reach a high near 26°C midday then cool to around 21°C by the evening. Winds will ease in the evening and Winnipeg will have a pleasant night: clear skies, light winds, and a low near 12°C.

Dew points will climb into the mid-teens on Monday afternoon, bringing the first notable humdiity of the year to the region. Drier air will return through Tuesday and Wednesday.
Dew points will climb into the mid-teens on Monday afternoon, bringing the first notable humdiity of the year to the region. Drier air will return through Tuesday and Wednesday.

Wednesday will see a high pressure system pass by to the south. It should keep winds light with a few clouds through the day. Temperatures will be warm again, though, with a high near 27 or 28°C. Another low pressure system moving through Saskatchewan will lift a warm front northwards through the province overnight. As it moves through, it will bring a chance of showers and/or thunderstorms to Winnipeg overnight.

Technical Thunderstorm Discussion

There is a widespread thunderstorm threat over the southeastern Prairies today. Although many ingredients are in place, the overall situation is conditional. Going over the MIST ingredients:

  • Moisture: Dew point values are forecast to rise into the mid-teens. There is a bit of uncertainty in this as dew points have been trending below model forecasts lately. That said, yesterday evening a pool of 15°C dew points was in place over western South Dakota. With the low-level jet continuing advection overnight, it seems likely that dew points should rise substantially towards forecasted values as the day progresses.
  • Instability: These dew points are forecast to produce MLCAPE values between 1000 and 1500 J/kg over SE Saskatchewan and SW Manitoba this afternoon. This instability will spread eastwards into the Red River Valley this afternoon. The instability will continue overnight with forecast MUCAPE values near 1000 J/kg spreading into the southeastern corner of the province.
  • Shear: Weak upper-level winds will limit shear in areas of greatest CAPE; only ~15 kt of 0-6 km bulk shear is forecast. Closer to the warm frontal boundary, strengthening upper-level winds increase the shear into the 30 to 35 kt range. Shear profiles are generally veering and would support primarily multicell thunderstorms.
  • Trigger: The warm front will be the primary area of focus, but strong capping will likely delay initiation until evening. Broad destabilization over southwestern Manitoba as the low approaches may trigger surface-based convection, but the storms may struggle to organize due to the lower shear values and poor ventilation aloft.

The best chance for thunderstorms looks to be over western and southwestern Manitoba this afternoon. These thunderstorms may be with the potential for some marginally severe thunderstorms. Heading into the evening, some of the activity will spread into the Red River Valley. It will likely become less extensive as the night progresses. The threat for severe thunderstorms will diminish as the night goes on.

Long Range Outlook

After Wednesday, Winnipeg will see the warm weather continue, but skies will be variable as several disturbances make their way through. These will bring several chances for showers or thunderstorms to the city that may persist right into the weekend. At least overnight lows will stay in the low to mid-teens and those chilly mornings will be a memory of the past by then!

Today’s seasonal daytime high in Winnipeg is 22°C while the seasonal overnight low is 9°C.