Arctic Assault on Winnipeg

While we had a glimpse of how absolutely wonderful it will be for summer to be here over the past few days as temperatures shot up into the mid-20’s, the spring-that-never-ends is making an ugly return as multiple shots of Arctic air invade the Southern Prairies.

Arctic air invading the Southern Prairies

Cold Arctic air blasting south over the Prairies. Image from the NAM valid at lunchtime today.

Temperatures through the remainder of the week are going to go from below-normal to more-below-normal as the above pictured cold front continues to slump southwards. The cooler weather was ushered in overnight as the cold front passed through Winnipeg bringing strong, gusty northerly winds. Temperatures today will only climb to around 13°C with strong northerly winds gusting as high as 60km/h. Temperatures will dip down close to the freezing mark under clear skies tonight with widespread low temperatures of around 2°C.

Wednesday

13°C / 2°C
Clearing & windy from the north.
Thursday

15°C / 5°C
Mainly sunny.
Friday

12°C / 0°C
Cloudy with chance of late-morning showers. Clearing in the afternoon.

The rest of the week won’t fare much better. Temperatures will try to climb a little closer to normal tomorrow with highs reaching around 15°C. The low tomorrow night will be a little milder at around 5°C as some warmer air is pushed over the province ahead of an intense low pressure system working it’s way out of Alberta through Saskatchewan.

Friday will be fairly cloudy as yet another cold front sweeps through the Red River Valley. There may be a few showers along the cold front as it pushes through in the late morning and early afternoon, but only a couple mm of rain would be likely to fall, if any. Northerly winds in behind the cold front will clear the skies but limit our high as colder air is ushered in yet again. Overnight lows will drop close to 0°C on Friday night under clear skies.

Long-Term

A cold weekend is ahead of us as we move even deeper into the Arctic air mass. Saturday will be the coldest day with daytime highs only in the mid-to-high single digits with another night with temperatures at or just below 0°C. Conditions will improve on Sunday as the coldest air moves off to our east and the daytime high rebounds into the mid-teens.

At this point, it’s looking like we’ll be in for a huge turnaround early next week. Very warm air is expected to flood across the Prairies as an upper ridge begins building in. At this point it looks like we will start off next week with daytime highs rocketing back up into the mid-20’s. At this point it looks like 24 or 25°C is entirely possible with a slight chance we’ll see temperatures climb into the upper 20’s. The large-scale pattern shift looks like we’ll be moving into a more stable warm pattern, so just make it through the next 5 days and we’ll be enjoying summer!

Warmest Weather of the Year so Far on Tap

This week will start out with the warmest weather we’ve seen so far this year.

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A surface high will bring a mild southwesterly flow to Southern Manitoba on Monday and Tuesday

Monday and Tuesday

Monday
image
Mainly Sunny
22°C / 7°C
Tuesday
image
Mainly Sunny
23°C / 5°C

Monday and Tuesday will be two very nice and very similar days. Both days will feature high temperatures in the low to mid twenties in Southern Manitoba with sunny skies. The wind will be from the south-west on both days and may become a bit breezy in the late morning and afternoon hours. Other than that there isn’t much negative to say about the start of the week…except that our first twenty degree weather of the year won’t fall on a weekend!

Wednesday

Wednesday
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Mainly cloudy. Chance of showers.
12°C / 3°C

A cold front will move through Southern Manitoba on Tuesday night, setting up cooler conditions for Wednesday. This will be a fairly strong front, but the lack of moisture ahead of it will mean little if any rainfall is expected as it passes. Temperatures on Wednesday are expected to be in the low teens with a strong north wind.

Long Range

The rest of this week looks to remain on the cooler side, with temperatures remaining in the teens on Thursday and Friday. By Friday conditions may rebound back close to seasonal values, but unfortunately models show an arctic high pressure system dropping south into our area just in time for next weekend.

Small Warm-Up

We’ll see warmer conditions for the beginning of this week. Temperatures may even climb above normal!

Shower activity on Monday

Light rain over parts of Manitoba on Monday

While Sandy hits the eastern coast of the United States hard during the early part of this week, the weather in Southern Manitoba will be very quiet. Temperatures on Monday will be in the mid to upper single digits in Southern Manitoba, which is near to slightly above the average daytime high of 5C. In terms of precipitation, a passing upper-level disturbance on Monday will generate cloud and some light showers in Southern and Central Manitoba. The most favoured area for shower activity is Western Manitoba, though other parts of Southern Manitoba stand a small chance of seeing a light rain shower. On Tuesday a passing trough of low pressure may once again generate a few showers, though they will be very light and scattered in nature. Tuesday’s high temperatures will be very similar to Monday’s, once again being in the mid to upper single digits.

Halloween Wednesday will be a chilly day, as cool north-westerly winds flow out of a surface ridge over Saskatchewan. Temperatures during the daytime will only be slightly above zero, but will drop near to or slightly below zero by the trick or treating hours. No precipitation is expected on Wednesday.

Conditions through late week will remain fairly seasonable, with daytime highs hovering near to or slightly below 5C. No major shifts in our weather are expected in the foreseeable future. In general, seasonable to slightly below seasonal values are expected over the next while.

Lingering Showers Give Way to Unsettled Weekend

A few lingering showers will persist through the Red River Valley this morning as the low pressure system that has been bringing us rain the last couple days slowly pushes eastwards. Conditions won’t improve too much, however, as we’ll be dealing with unsettled weather, albeit a little dryer, through the weekend.

Rainfall accumulations through the day today.

This 12 hour rainfall accumulation map shows the total rainfall that the RDPS model is forecasting for the daytime today.

Showers will slowly taper off through the Red River Valley today from west to east with only a further 2-4mm in rainfall accumulations. This system has brought hugely varying rainfall amounts across the RRV, with general amounts from 20-60mm across the Red River Valley. After spending several months in a row with below-normal precipitation, this system has pushed Winnipeg back to above-normal accumulations for October, which will begin to chip away at our deficit for the year. Winds will also taper off through the day today as we move to a high of only 7 or 8C.

Saturday will be a mainly cloudy day with a slight chance of showers and a high near 11C.

A frontal wave pushes across Southern Manitoba on Sunday, occluded from the parent low that will be captured over Northern Saskatchewan by an upper low in the area. Some uncertainty exists to the amount of precipitation associated with this wave as it moves through. Some models have next to no precipitation, while the GDPS is suggesting as much as 10-15mm of rain. My personal feeling is that we’ll likely see some rain push through with general amounts in the 4-8mm range across much of the RRV. We’ll keep an eye on this system and provide some updates through the weekend in the comments below. Sunday will likely be mostly cloudy again, with a high near 10C.

The biggest weather feature next week looks to be the potential for a significant low pressure system to push into North Dakota, bringing rain, snow, and potentially blizzard conditions to the Red River Valley for the second half of the week. That’s a long ways away, though, and a lot can change between now and then. We’ll be sure to follow this potential system closely through the week ahead.