Beautiful Days Ahead

Beautiful weather will continue across southern Manitoba through the next few days as a ridge of high pressure works it’s way across the Province. Things will turn stormier heading into the weekend as a potent upper trough pushes inland from the Pacific.

Today & Tomorrow

Wednesday

25°C / 12°C
A few clouds in the afternoon.
Thursday

25°C / 12°C
Description

Over the next couple days mainly sunny skies will dominate as a surface ridge slowly works it’s way across the province. Unlike the past couple days where we’ve enjoyed sunny skies here in the Red River Valley while areas further north in the Interlake and Central Manitoba were stuck underneath extensive cloud cover & showers, pretty much the entirety of Manitoba will be seeing plenty of sun and temperatures in the mid–20’s. Today we’ll climb to around 24°C and probably climb a degree or two higher for Thursday. Overnight lows will be comfortably seasonal, dipping down to around 12°C.

Things will begin taking a turn on Friday, though, as a strong southerly flow develops which will begin to push heat and moisture northwards through the High Plains and into the Southern Prairies. While it looks like the end of the week will have quite a bit of thunderstorm activity in Saskatchewan, things aren’t quite as clear cut here. Let’s take a look at how things look to pan out for us right now.

Friday

Friday

23°C / 13°C
Increasing cloud with risk of a thunderstorm. Chance of thunderstorms overnight.

A strong southerly flow will develop on Friday as the upper trough begins it’s way inland. Winds will increase to around 40km/h up and begin to bring moisture northwards. This will feed into a broad area of low pressure working it’s way across the Prairies. With the strong feed of moisture streaming northwards, we’ll likely see increasing cloudiness fairly early in the day which will limit our daytime high to a few degrees cooler than today or tomorrow. At this point, no severe storms are expected in the Red River Valley although a few scattered thunderstorms may manage to pop up, especially over the western RRV; for severe storms conditions look to be far more favourable further west in Eastern Saskatchewan or extreme SW Manitoba where the apex of the 850mb warm nose will reside with it’s associated low-level jet. Conditions there look favourable for the potential development of severe storms, although it may get messy very quickly with linear upscale growth shortly after initiation. Since the conditions there don’t directly pertain to the Red River Valley, I’ll leave a discussion of the severe weather potential for that region in the comments below.

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Rainfall forecast for Friday night (Sat 00Z – Sat 12Z) from the GDPS.

The storms that fire Friday evening will continue through the night at least as a band of rain but more likely as an organized area of nocturnal thunderstorms. The low looks to lift northwards through the night before continuing eastwards, and the storms are expected to follow suit, moving ENE after initiation. At this point, it looks quite likely that Friday night will be a stormy night in the Interlake, however in the Red River Valley things are more uncertain. With much of the forcing lifting northwards, storms may have a difficult time surviving further south where lift will not necessarily be lacking, but not nearly as focused. Wherever the storms do go, the threat for severe storms will likely continue into the night. A strong 40+kt 850mb low-level jet will provide ample lift and moisture for the system and help maintain 1000+J/kg MUCAPEs through the night. The main threat with these storms would be large hail and the potential for strong straight-line winds.

We’ll keep a close eye on this system and have a more comprehensive look at it on Friday morning’s post. Until then, get out there and enjoy the beautiful weather!

Pleasant End to the Week

A pleasant second half to the week is on the way with near-normal temperatures and lots of sunshine. Daytime highs will sit near 22°C through the rest of the week with overnight lows around 10 or 11°C. Winds will remain light through today and tomorrow then start to pick up to 20–30km/h out of the south by Friday afternoon. Not a whole lot to say other than it will be quite pleasant!

Wednesday

21°C / 10°C
Mainly sunny.
Thursday

22°C / 11°C
Sunny
Friday

22°C / 11°C
Mainly sunny.

The Weekend

Looking ahead to the weekend, it’s looking more and more likely it will be showery with with a risk of thunderstorms. An upper low is forecast to track across Southern Manitoba on Saturday supporting two lows: one that will track through the Interlake region tied closely to the upper low and a second low pressure system that will track through North Dakota tied to the associated frontal wave[1].

Lifted Index for Saturday Afternoon from the GFS

Lifted Index for Saturday Afternoon from the GFS.

At this point, strong instability is forecast through the Northern Plains of the United States with LI values (shown above) near –10°C showing some fairly significant instability. CAPE values south of the border are also forecast to climb into the 2500–3000J/kg range.

Further north, instability is forecast to be sitting over Southern Manitoba, although the weaker LIs of only of only around –2°C mean that we’ll need stronger forcing to get any significant storms going; with the frontal wave in the US I’m inclined to say that we’ll see more cloudy/showery weather than the potential for any significant storms. Rainfall amounts shouldn’t really come close to the last two systems, although convection in the United States is expected to feed moisture northwards into the upper low and it will spread it out into a band of showery rain again. As the system passes through, more showers are expected on the back side on Sunday.

That’s all still a long ways out, though. We’ll keep an eye out and be sure to give more details by week’s end.


  1. The frontal wave of a system is it’s associated warm & cold fronts.  ↩

A Cool But Dry Start to the Week

Below-seasonal temperatures will persist through the beginning of this week but that gloomy news will be offset by the fact that we should see plenty of sunshine over the next couple days. A disturbance tracking through the Dakotas will bring a chance of showers for the Red River Valley on Wednesday as it pushes the coldest air out of the Red River Valley and pushes us back towards seasonal temperatures.

Monday
image
19°C / 6°C
Sunny. Increasing cloud overnight.
Tuesday
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18°C / 7°C
Mainly cloudy. Chance of showers near the U.S. border.
Wednesday
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16°C / 7°C
Clearing in the afternoon. Channce of showers near U.S. border.

Monday

We’ll see nothing but sun today as a ridge of high pressure dominates the weather over the Red River Valley. Daytime highs will sit near 18 or 19°C. We’ll have another cool evening tonight with lows dipping to around 5°C.

Tuesday & Wednesday

Cloud will begin to push in on Tuesday as a low pressure system begins to work it’s way into North Dakota. The chance for precipitation in Winnipeg is very minimal, but closer to the international border it’s more likely that a shower or two will be seen. A sharp cutoff is expected from accumulating rain to nothing, and while the models have been trending towards keeping all the rain on the US side of the border, it’s important to note that around 10mm of rain is forecast for areas only 75–100km south of the Canadian border.

GDPS Precipitation for Tuesday.

Rainfall expected through the day on Tuesday. A sharp cutoff is expected from the accumulating rainfalls in North Dakota and little-to-no rainfall in Southern Manitoba.

While just a few spits of rain is most likely for soaked communities in the southern Red River Valley, we’ll definitely be keeping our eyes on it. If the system ends up just a bit further north than forecast, areas such as Treherne, Morden, Gretna, Altona, Letellier & Emerson could see some light rain. For now, though, I’m expecting just a chance for a shower or two.

Rest of the Week

Heading through the rest of the week it looks like we’ll see couple of mainly sunny days on Thursday & Friday with temperatures climbing back to seasonal[1]. The weekend is worth keeping an eye on as another strong upper low is forecast to move into the region bringing showers and the potential for a few thunderstorms.


  1. The normal daytime high for Winnipeg at this time of year is around 22°C.  ↩

Sunny Week Ahead; Potentially Stormy End To The Weekend

The remainder of this week will be filled with sun as yet another Arctic ridge dominates over the Eastern Prairies, continuing the unshakable grasp of winter. While temperatures will be milder compared to the first half of the week, we’ll reamain well below our normal of around +9°C but with the milder temperatures the sun should be able to continue slowly melting the snow we have. Unfortunately, it’s looking like a fairly significant storm may bring another shot of winter.

This Week

Wednesday

0°C / -14°C
Sunny
Thursday

2°C / -10°C
Sunny
Friday

4°C / -8°C
Mainly sunny; increasing cloudiness in the evening.

A significant Arctic high pressure system will lay dominant over the Eastern Prairies over the next few days with the main ridge axis running from near Churchill towards southwestern Manitoba. We’ll see temperatures slowly climb over the next few days, but our daytime highs will likely remain in the 0-4°C range, although any areas in the city that have managed to become mostly snow-free may get a little warmer than that. Regions outside the City of Winnipeg will likely top out within that range. Perhaps most significantly will be the warming of our overnight lows, which will be in the low minus teens this mronign and move into the minus single digits by the end of the week.

We’ll have plenty of sunshine over the next few days with some clouds starting to work their way into the Red River Valley on Friday night associated with a weakening system pushing through Saskatchewan.

The Weekend

GDPS 24 Hour Precipiation Accumulation valid Monday morning.

24hr. precipitation accumulation valid Monday morning from the GDPS. Current forecast shows the potential for up to 25mm of liquid equivalent precipitaiton.

Saturday looks to be a mix of sun and cloud, but Sunday will be quite an interesting day weather-wise as a Wyoming low pushes northeastwards into southern North Dakota through the day. While the morning looks to start off cloudy, the GDPS1 deepens the low significantly through the afternoon, spreading precipitation northwards into Southern Manitoba. There’s still plenty of time and uncertainty, but this system (at the moment) looks like it could end up producing as much as 15cm of snow. How much actually accumulates will vary highly, since temperatures are expected to be right near 0°C and non-snow-covered surfaces will likely melt much of the snow on contact for the first several hours of the event. There’s also the possibility enough warm air will wrap north of the system that some of the precipitation will fall as rain instead of snow. This system would impact us through Monday as well given the current model output. We’ll keep our eyes on the development of this system; stay tuned.


  1. Global Deterministic Prediction System