Lovely Fall Weather Continues

Seasonably mild temperatures will continue across southern Manitoba in what has been a pleasant fall so far.

RDPS 2m Temperature Forecast valid 21Z Tuesday October 17, 2023
An approaching low pressure system will bring very mild late-October temperatures to southern Manitoba on Tuesday.

A low pressure system advancing towards the province will bring some cloud cover and mild weather to Winnipeg today. With skies becoming mixed this morning, temperatures will warm into the mid- to upper teens this afternoon.

The low will begin moving through the region this evening, bringing with it a chance of rain showers. The heaviest rain will likely end up southeast of Winnipeg with amounts near 5 to 10 mm. Amounts will quickly drop off to the northwest of this; Winnipeg will sit along the edge, but at least a couple millimetres of rain seems likely. It will be a warm night with a low near 10 °C.

On Wednesday, northerly winds will pick up behind the low as any lingering showers move out of the region. Temperatures will rebound back into the mid-teens with northerly winds up to 30 gusting 50 km/h. Skies will take their time clearing out, but Winnipeg will likely see a bit of sun before evening.

A ridge of high pressure will move through the province on Wednesday night and Thursday. This will allow temperatures to dip into the -5 to 0 °C range on Wednesday night. On Thursday,  temperatures will bounce back into the mid-teens again as another push of warmer air moves in from the west. A weak low will slide through the region on Thursday night, bringing with it another chance for some light rain showers.

Long Range Outlook

Friday will mark the start of a gradual transition of southern Manitoba’s weather into a cooler, more unsettled pattern. On the back side of Thursday night’s low, cooler temperatures will gradually slump into the Prairies from the Arctic. As this cold front pushes south over the next week, disturbances will ripple northeastwards ahead and along it, bringing waves of rain or snow to the Prairies.

This will result in variable cloudiness turning mainly cloudy next week and gradually cooling temperatures in Winnipeg. There will be a chance of some rain on Saturday, as well as a more organized chance of accumulating rain early next week. By mid-week, lake-effect rain showers will likely return to southern Manitoba.

Daytime highs will cool to the 0 to 5 °C range with overnight lows well below freezing through this period. The region could also see some of the first snowflakes of the season late next week.

Today’s seasonal daytime high in Winnipeg is 9 °C while the seasonal overnight low is -1 °C.

Sunshine Returns as Seasonal Fall Weather Settles In

Sunshine will gradually return to Winnipeg over the coming days as cooler fall weather settles into the region.

RDPS 2m Temperature Forecast valid 21Z Sunday October 8, 2023
Cooler temperatures will descend into the eastern Prairies for the weekend while warmth builds in the west.

The Red River Valley will see mixed skies today as an unsettled air mass moves through the region. Cool temperatures combined with north-northwest winds will result in some persistent lake-effect rain bands. These could be a bit intense at times, and will shift eastwards and weaken as the day progresses. This will result in a chance of showers for many areas in the Red River Valley this morning, then tapering off into the afternoon.

It will be a cool day across the region; highs will reach around 10 °C with northwest winds around 30 gusting 50 km/h. The showers and cloud will clear out this evening as a ridge of high pressure builds in. Temperatures overnight will bring a good chance of some frost to the region as the winds taper off and temperatures dip to around 0 °C.

A weak disturbance rippling along in the flow could bring a few showers to southern Manitoba on Saturday morning, but it looks like the precipitation will likely stay north of the Red River Valley.

A ridge of high pressure will keep things on the sunnier side through the weekend with seasonal highs in the low teens and overnight lows dipping close to the freezing mark.

Long Range Outlook

Through the weekend, an upper ridge will build in the west and some warmer weather will move into Alberta and Saskatchewan. For Manitoba, a deep upper trough is forecast to shift east and mature in to a broad vortex that stalls out over eastern Canada, perhaps even retrograding a bit into next week.

As a result, the warm air will be shunted northwards into the Northwest Territories and Nunavut while cooler near-seasonal temperatures likely remain entrenched over Manitoba through next week.

Today’s seasonal daytime high in Winnipeg is 13 °C while the seasonal overnight low is +2 °C.

Wet, Unsettled Weather Ahead for Winnipeg

A slow-moving complex of low pressure systems in the northern United States will spread cloud cover and waves of showers across southern Manitoba through the coming days.

ECMWF Total Accumulated Precipitation valid between 00Z Thursday September 22 and 00Z Monday September 25, 2023
Multiple waves of rain will move across southern Manitoba in the coming days, with the potential for some higher rainfall totals by Sunday evening.

Waves of rain will move through the Red River Valley over the coming days, but it will at least be relatively mild through the weekend. Despite the unsettled weather, daytime highs will climb to around 20 °C over the coming days. The cloud cover will also keep nights warmer with lows dipping down into the mid-teens. Throughout next few days, the wind will also be consistently out of the east, often in the 20 to 30 km/h range.

The rainfall forecast is a bit tricker than all the other elements, largely due to the complexity of the interacting systems south of the border and how thunderstorm activity will evolve as this disturbance matures.

Today, Winnipeg will likely see on and off showers continue through the morning, then things will have a chance to dry out a bit as the showers shift towards the west. Another wave of rain will push into southern Manitoba overnight and persist into Saturday morning. Things should mostly dry out on Saturday afternoon, but a few pop-up showers may be possible if the sun peeks out a bit and warms things up, or depending on the timing of this system, the cloud and rain could drag on later into the day.

The rain will calm down for Saturday evening, but then another broad area of rain will push northwards into Manitoba overnight, this time as the entire system in the United States begins shifting northwards. More rain will likely move through, and then lingering showers or drizzle could persist through the day on Sunday.

Long Range Outlook

The rain should taper off for Monday, but the region could see a lot of leftover cloud cover through the day. By Tuesday, the sun should begin poking out again and Winnipeg will see several pleasant days with highs in the low 20s and lows in the low teens.

Today’s seasonal daytime high in Winnipeg is 16 °C while the seasonal overnight low is 4 °C.

Seasonal Temperatures With A Chance of Unsettled Weather

Seasonal temperatures will continue for much of the week across southern Manitoba, but a passing low pressure system on Saturday may replace sunshine with unsettled conditions.

RDPS 2m Temperature Forecast valid 21Z Thursday September 14, 2023
A low pressure system crossing Manitoba will bring warmer weather to the region on Thursday.

A collapsing upper ridge will gradually push into Manitoba as it weaken over the next couple days, bringing plenty of sunshine but not too much warmth. High temperatures in Winnipeg will sit close to 20 °C over the next couple days with a few clouds on Wednesday afternoon. The winds will be light on Tuesday, but could reach up to 30 km/h on Wednesday afternoon.

More cloud will move into the region on Wednesday night as a low pressure system crossing the northern Prairies pushes a warmer air mass into the region. Some showers might move through the region overnight Wednesday as this warmer air pushes in. This warmer air mass will help with overnight lows; Wednesday night will likely only drop into the low teens, compared to a low near 5 °C tonight.

On Thursday, highs temperatures will climb towards the mid-20s across southern Manitoba. Instability will grow through the day as a warm-sector trough pushes into the Red River Valley. As a result, there will actually be a small chance of some showers or thunderstorms later in the afternoon and early evening. With only around 500 J/kg of MLCAPE and 20–25 knots of bulk shear, any severe weather is highly unlikely. 

A cold front will sweep through on Thursday night, bringing seasonal temperatures back to the region on Friday.

Long Range Outlook

The region will see near-seasonal temperatures along with a mix of sun and cloud into the weekend. There will be a slight chance of showers on Friday night as some wrap-around precipitation moves across the region as an upper low exits the region.

Some warmer weather will likely push in to start next week with daytime highs climbing back towards the mid-twenties.

Today’s seasonal daytime high in Winnipeg is 19 °C while the seasonal overnight low is 7 °C.