Turning Unsettled As Warm, Humid Weather Arrives

Brad Leave a comment

A warm and increasingly humid air mass will move into Winnipeg this week, bringing chances for showers or thunderstorms to the region.

An upper-level disturbance moving through southern Manitoba will bring cloudy periods to Winnipeg today. There will be a chance of showers, but most of the rain will pass to the north of Winnipeg. The best chance for any rain will be in the morning and midday hours. Temperatures will warm up in the afternoon with some sunshine poking through the clouds to a high near 26 °C. Skies will clear out tonight with a low near 15 °C.

Tuesday will start the move towards a warmer and more humid air mass. A sharp upper-level trough will dig over the western seaboard with an upper ridge over the eastern Prairies developing in response. Skies will stay mainly sunny as a warm front begins lifting towards Canada through the Northern Plains. Winnipeg will see light northeasterly flow ahead of the warm front through the day as temperatures head to a high near 30 °C.

RDPS 12-hr Accumulated Precipitation Forecast valid 12Z Wednesday June 9, 2021
Showers and thunderstorms will develop in the United States on Tuesday night and spread across southern Manitoba by Wednesday morning.

On Tuesday night, a low pressure system lifting out of Montana will support a strengthening flow overrunning the warm front. The combination of lift and destabilization will produce thunderstorms over the northern Plains that will push across southeastern Saskatchewan and southern Manitoba into Wednesday. There will be enough instability and organization in the environment for the risk of severe thunderstorms. The primary threats overnight would be hail and wind. There is also a chance that the thunderstorms may organize into a squall line. If they did so, it could bring damaging winds to portions of southeastern Saskatchewan and/or southern Manitoba overnight.

Temperatures will head to a low near 18 °C on Tuesday night.

RDPS 2m Dew Point Forecast valid 21Z Wednesday June 9, 2021
Humid conditions will spread across southern Manitoba on Wednesday.

On Wednesday, the warm front will lift northwards into southern Manitoba. This will combine with an upper level disturbance moving into the region to support scattered showers and/or thunderstorms. The cloud cover will keep temperatures cooler than Tuesday, but it will become substantially more humid. Although the high will be around 26 °C, dew points will climb into the 18–20 °C range and make it feel closer to the low 30s. The unsettled weather will push off to the northeast for Wednesday night with a low near 17 °C.

Long Range Outlook

The warm and humid weather will stick around for the rest of the work week with highs in the mid-20s and dew points hovering in the upper teens. The sun should return for Thursday afternoon, then another passing low will bring a chance showers and thunderstorms to the region on Friday. A cold front will sweep through after that, ushering in drier conditions for the weekend. Temperatures will stay warm into next week with highs in the 25–30 °C range.

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

Hot, Unsettled Weather Ahead

Brad Leave a comment

Winnipeg will see very hot and unsettled conditions heading through the weekend.

A low pressure system crossing the province today will send temperatures soaring in Winnipeg. South-southwest winds of 30–40 km/h will usher in a hot air mass with highs climbing into the mid- to upper-30s. The dew point will stay in the low teens which will mean, fortunately, that the humidity won’t make the heat feel any worse than it already is. A “cold” front will sweep southwards through the Red River Valley later today. This front will bring a risk of thunderstorms to the region as it passes, although the most likely area to see any convection will be south near the U.S. border. Winds will shift to the north behind the front and then ease overnight. Temperatures will head to a low near 18 °C.

RDPS 2m Temperature Forecast valid 18Z Friday June 4, 2021
Temperatures will climb into the mid-30s by lunch time today across portions of southern Manitoba.

On Saturday, moderate southerly winds will bring more hot weather back into the region as another low pressure system moves into the province. Temperatures will climb back into the mid-30s but this time humidity will accompany it. Dew points will climb into the mid- to upper teens, making it feel closer to +40 out. That heat and humidity will meet another cold front pushing into the Red River Valley late in the day. This combination will bring a risk of thunderstorms — potentially severe — to the region Saturday evening and overnight. Temperatures will head to a low near 19 °C.

3km NAM Simulated Reflectivity Forecast valid 07Z Sunday June 6, 2021
Many weather models show the potential for nocturnal thunderstorm development on Saturday night into Sunday morning.

Drier, slightly cooler air will work into the region on Sunday. The morning will start with some lingering cloud with a chance of showers or thunderstorms as the cold front slowly continues to push through the valley. It should be off to the east by late in the morning with skies clearing for the afternoon. Temperatures will climb to a high near 27 °C with a moderate westerly wind bringing more comfortable humidity levels to the region. Skies will stay clear on Sunday night with a low near 14 °C.

Long Range Outlook

Next week will start with mainly sunny skies and highs near 30 °C again. Forecasts show more unsettled conditions developing mid-week, then gradual cooling back towards seasonal values by the weekend.

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

Blazing Heat Building In

Brad Leave a comment

Temperatures will soar in Winnipeg through the second half of the week as a potent upper ridge builds across the Prairies.

The heat will be remarkable for early June as temperatures climb through the 30s over the next few days. The heat will likely challenge records for the Winnipeg area, particularly on Thursday and Friday. Thursday’s high of 33 °C will challenge the existing record of 32.8 °C set in 1968. Friday’s intense push of heat will send highs into the upper 30s and likely break the existing record high of 35.6 °C set in 1988. The overnight lows may even challenge record warm minimum temperatures which sit at 18.3 °C for both June 4th and 5th, set in 1976.

Environment and Climate Change Canada has issued a heat warning for much of southern Manitoba. Tips to beat the heat can be found on the City of Winnipeg’s emergency preparedness page.

RDPS 2m Temperature Forecast valid 21Z Friday June 4, 2021
Temperatures will be very hot over southern Manitoba on Friday with highs in the 35–40 °C range.

The city will see plenty of sun throughout the next few days. The most notable non-heat element of the weather will occur overnight into early Thursday morning. A strong upper-level jet will generate some showers and/or thunderstorms over the northern Prairies on Wednesday afternoon. This cluster of instability will move southwards into southern Manitoba through the evening and overnight hours. Winnipeg will see a chance of showers or thunderstorms overnight with the highest chance after midnight. These storms won’t have any organized risk of severe weather, but dry low-levels mean that some moderate to strong wind gusts will be possible with them as they move through.

Some lingering cloud from these systems will stick around on Thursday morning, then skies should clear for the afternoon.

Long Range Outlook

The heat will continue with daytime highs in the 30s on Saturday, then highs will ease back into the upper 20s Sunday into next week. Conditions will also turn more unstable this weekend, with an increasing chance of showers or thunderstorms beginning Sunday night and persisting into next week. The above-seasonal warmth will persist right through next week with highs in the mid- to upper-20s and lows of 15–20 °C.

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

Heading Into A Heat Wave

Brad Leave a comment

Winnipeg will see temperatures soar this week as scorching heat builds into the region.

Winnipeg will see plenty of sunshine over the next few days as an upper ridge builds into western Canada. On Tuesday, a weak low moving through southern Manitoba will bring a few more clouds into the region. As it slumps southwards, it will bring a chance for scattered showers or thunderstorms. The support for thunderstorms will be weak — bulk shear will sit at 20–30 knots and try to offset the limited energy — but there will likely be enough forcing to support a few. Skies will clear out again for Wednesday.

RDPS 500mb Wind and Temperature Forecast valid 21Z Wednesday June 2, 2021
A potent upper ridge will build out of the western United States into the Canadian Prairies this week.

The big story will be the building heat this week. As the upper ridge strengthens over the Prairies, Winnipeg will see daytime highs rise from the low 20s today to around 30 °C by Wednesday. Overnight lows will follow suit increasing into the upper teens by mid-week.

Long Range Outlook

The heat will continue to build through the latter half of the week. Daytime highs should peak on Friday in the mid- to upper 30’s as overnight lows stay in the upper teens. Fortunately, dew points are forecast to stay in the low to mid-teens, so humidex values won’t be a significant component of the heat wave. The hot weather will continue into the weekend, then begin to ease as unsettled conditions develop on Sunday into next week.

Today’s seasonal daytime high in Winnipeg is 22 °C while the seasonal overnight low is 8 °C.