Tag: Lake-Effect Precipitation

Cooler Weather Settles In

Brad Leave a comment

Just like that, fall weather has arrived in the Red River Valley with temperatures over 10 °C cooler than seen on the weekend.

RDPS 2m Temperature Forecast valid 12Z Friday October 4, 2024
The first freeze of the season could arrive by Friday morning.

Today marks the start of fall weather in southern Manitoba, courtesy a much cooler air mass brought in by yesterday’s cold front and very gusty winds. This change reflects a major shift in the large-scale weather pattern; the upper ridge over the Prairies has collapsed, and a quasi-stationary upper low is becoming established over the western coast of Hudson Bay. This change will result in a more west to northwest flow aloft over Manitoba, ushering in seasonal conditions for this time of year.

The result will be a week filled with daytime highs in the mid-teens and overnight lows dropping into the 0 to 5 °C range with a risk that we may see the first frosts of the season.

For a bit more detail, today will bring cloudier conditions with lighter winds than yesterday. A high pressure system passing to the south will spread southwest winds of 20 to 30 km/h into the region as temperatures climb into the mid-teens. A weak disturbance slumping southeastwards across the Prairies will keep conditions cloudy tonight; this will ensure that the overnight low stays mild (for this week) at around 10 °C.

Another cold front will sweep through on Wednesday, bringing gusty northwesterlies and cooler temperatures back to the region. With the cooler temperatures moving in and the prolonged northwesterly flow, some lake-effect showers may develop. Winds will likely keep these north of Winnipeg, but worth noting the possibility for areas in the northern Red River Valley.

A ridge of high pressure will push into the province behind the front, bringing clearing skies and sending overnight lows to near-freezing for the rest of the work week. A widespread freeze could be possible over southern Manitoba overnight Thursday into Friday morning.

Long Range Outlook

A moderating trend will develop over the weekend across southern Manitoba with daytime highs heading back towards the upper teens. Overnight lows will also follow the warming trend, likely heading back into the 5–10 °C range through the weekend.

The region will see variable cloudiness, but little to no precipitation is expected.

Today’s seasonal daytime high in Winnipeg is 15 °C while the seasonal overnight low is +3 °C.

Cool Conditions Ahead for Winnipeg

Brad Leave a comment

The broad pattern change that began this week will establish itself by the weekend, bringing a prolonged period of seasonably cool conditions to the region.

RDPS 2m Temperature Forecast valid 21Z Saturday October 28, 2023
Seasonably cool temperatures will flood the Prairies this weekend with daytime highs below freezing in most places.

The weather pattern across southern Manitoba will be dominated by a slow-moving upper trough extending from an Arctic vortex over Canada’s eastern Arctic. This will ensure a pipeline of cooler air sourced from the Arctic sits pointed at the region right into next week, delivery seasonably cool temperatures to the area.

It will be mainly cloudy in Winnipeg today with some morning snow tapering off as a disturbance tracks off the the east. In its wake, northerly winds up to 30 gusting 50 km/h will pump cooler air southwards, supporting bands of lake-effect flurries off of both Lake Manitoba and Lake Winnipeg. This will result in a few flurries lingering through the day, as well as some more concentrated bands of snow in the lee of the lakes. Temperatures will climb to around the freezing mark, then dip down into the -5 to -10 °C overnight as skies clear.

Sunnier skies will return for Saturday with highs in the -5 to 0 °C range with southwesterly winds in the 20 to 30 km/h range. A bit of cloud will push back into the region on Saturday night, but lows will still dip down close to -10 °C.

On Sunday, there will likely be a bit more cloud around with just a slight chance of some flurries. Temperatures will again climb into the -5 to 0 °C range with westerly winds again near 20 km/h.

Long Range Outlook

Highs will likely bounce back to the freezing mark on Monday with a passing disturbance that will also bring some light snow to the region, then cooler weather returns for the rest of the week with highs in the -5 to 0 °C range and overnight lows closer to -10 °C.

For Halloween, it’s looking like it will be a partly cloudy day with a cool high near -5 °C. By the time kids start heading out in the evening, temperatures will likely have dipped into the -5 to -10 °C range with southwest winds near 15 km/h.

Today’s seasonal daytime high in Winnipeg is 6 °C while the seasonal overnight low is -3 °C.

Sunshine Returns as Seasonal Fall Weather Settles In

Brad 1 Comment

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.

Seasonably Cool and Wet Weather Continues

Brad Leave a comment

A series of slow-moving low pressure systems will continue to bring cool conditions and periods of wet weather to southern Manitoba.

RDPS 2m Temperature Forecast valid 21Z Saturday October 15, 2022
A persistent northwesterly wind over the next few days will continue to funnel cool, Arctic air southwards over Manitoba.

We’re back from our break over the long weekend and, well, we hope you enjoyed the beautiful Thanksgiving weather. Now a distant memory, a series of low pressure systems are bringing much colder weather to the region.

A band of lake-effect precipitation from Lake Winnipeg will shift across the region today as winds shift to the north. This will bring a chance of flurries or showers to Winnipeg through the morning. Skies will stay cloudy most of the day, but the chance for any more precipitation should diminish into the afternoon. Temperatures will climb into the mid-single digits with easing winds.

The reprieve will be short lived, though. Another low pressure system will begin dropping southwards into central Manitoba tonight, spreading more rain southwards for Saturday. Most of the precipitation will fall east of Winnipeg, but the city will see a chance of seeing some rain. If the main area of rain from the system doesn’t affect the city, lake-effect squalls developing it its wake could. Temperatures will be warmer on Saturday with a high of 7 or 8 °C even though skies stay cloudy. Northwest winds of 20 to 30 km/h will persist through the day.

This entire complex of systems will finally begin to shift out of the region on Sunday. Unfortunately, that will also come with an Arctic high pushing into the region. Moderate northwest winds ahead of the high will usher cooler air into the region on Sunday, keeping daytime highs in the low single digits. The cloud cover will gradually break up, allowing temperatures to fall well below freezing on Sunday night.

Long Range Outlook

The cool weather will continue on Monday with highs in the low single digits, but the winds will be much lighter. Cool conditions will continue for Tuesday, then a return to more seasonal temperatures will arrive midweek. Drier weather should also return with the seasonal temperatures.

Today’s seasonal daytime high in Winnipeg is 11 °C while the seasonal overnight low is 0 °C.