Tag: Showers

Nice Start to the Week

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This week will start out fairly nice, with the exception of some showers on Monday.

A weather system will bring showers to Manitoba on Monday

Monday

Monday

Mainly cloudy a chance of showers, then clearing.
21°C / 10°C

Today will be a mixed day weather-wise. Showers are likely in the morning as a strong upper-level jet stream induces lift over the area. These showers are expected to taper off by this afternoon, with clearing skies thereafter. Once skies clear, temperatures should warm into the low twenties.

Tuesday and Wednesday

Tuesday and Wednesday look to be fairly similar days in Southern Manitoba. Both days should be mainy sunny with temperatures in the mid twenties. The wind should be fairly light, making conditions ideal.

Tuesday

Mainly Sunny
25°C / 13°C
Wednesday

Mainly Sunny
25°C / 12°C

Late Week

The late week forecast is unclear at this point. A strong longwave trough[1] will come onshore late in the week. This trough may generate a series of thunderstorm days across the Canadian Prairies and Northern US Plains. At this point the location and timing of storms is not known, but more details on this situation will be available as the week progresses.

  1. A longwave trough is a large-scale dip in the jet stream that is usually associated with strong weather systems and/or severe weather outbreaks.  ↩

Mixed Weekend Ahead

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The warm, mostly sunny weather of the past few days will give way to more unsettled conditions as a low pressure system anchors itself in Central Saskatchewan allowing a trough to sit over Southern Manitoba as a second low works it’s way across the Northern Plains of the United States. Showers will try to get going across Southern Manitoba but their coverage will be heavily limited by a lack of upper-level support over the region.

Today


24°C / 12°C
Sunny with cloudy periods. Chance of showers or a thunderstorm in the afternoon.

We’ll start off with some lingering clouds this morning with a chance of a few scattered showers as the remnants of a weak cold front wash out over the Red River Valley. We’ll then see a bit of short-lived clearing before skies cloud up this afternoon once we get warm enough to get some convection going. There will be enough instability around to produce a few afternoon showers or perhaps even a weak thunderstorm or two. Lifted Index values will be sitting at only –1 or –2°C which represents only marginal instability and CAPEs agree with values only around 500–750J/kg.

With little forcing in the area, the most favourable area for showers or thunderstorms will be near subtle convergence features; in our case, that will mean near either the western escarpment of the Red River Valley or any lake breeze convergence lines that form to the north and northwest of the city. At the moment it’s looking like the most potential for a thunderstorm sits west of Winnipeg in the Red River Valley, but there’s certainly a chance we may see an afternoon thunderstorm here in the city. Aside from the potential showers & thunderstorms, it will actually be a fairly pleasant day. Winds will be fairly light through the day and we’ll be climb to a high near 24°C. Skies will clear tonight as we head to a low of around 12°C.

Saturday & Sunday

Saturday

23°C / 12°C
Increasing cloudiness then a few showers or rain.
Sunday

24°C / 12·C
Mix of sun and clouds. Showers likely southwest of Winnipeg.

After a sunny start, skies will cloud over on Saturday as a trough connecting a low pressure system in central Saskatchewan and a low pressure system pushing into the Dakotas. There will some showers ahead of the trough line that will push through the Red River Valley in the afternoon. Rainfall amounts won’t be anything significant, but a localized 5–10mm can’t be ruled out. We’ll see a high near 23°C and an overnight low once again sitting near 12°C under clearing skies. Sunday will be a mix of sun and clouds with showers likely south and west of the Red River Valley. The high for the day will be around 24°C with an overnight low into Monday morning of about 12°C once again.

A Cool But Dry Start to the Week

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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
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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.  ↩

Risk of Thunderstorms to Start the Week

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One of our first risks for thunderstorms will come early this week.

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The green area outlines the risk of thunderstorms on Tuesday

Monday

Monday
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Mainly cloudy. Chance of showers.
21°C / 15°C

Today should be a generally dry day in Southern Manitoba with only a chance of showers. There is also a slight risk of a thunderstorm, but any storms that develop will be relatively weak. Temperatures will be in the upper teens or lower twenties in most areas under mainly cloudy skies. The wind will be from the south-east.

Our next reasonable chance for rain will likely come tonight night as a powerful impulse generates an area of rain. This rain is currently expected to be heaviest over Western Manitoba, but may affect the Red River Valley as well, albeit with lesser amounts. It is entirely possible that this rain could miss us completely, but it is too early to say exactly what will happen.

Tuesday

Tuesday
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Risk of a Thunderstorm
23°C / 10°C

Tuesday should feature our best chance of thunderstorms this week. A low pressure system and its associated cold front will pass through Southern Manitoba at some point during the day – likely through midday – and may trigger some storms. These storms are expected to be non-severe, but if there is a bit more instability than currently expected, there is a very slight chance that one of two may become marginally severe. The main risks with any storms that develop will be hail, perhaps up to nickel size, and gusty winds. The storms should be fairly fast moving so heavy rain is a lesser concern. Other than this chance of thunderstorms, there will also be a general chance of showers through the day. Temperatures will be in the low, or maybe mid twenties (depending on how the weather features setup), with a southerly flow switching to a westerly flow after the frontal passage.

Wednesday

Wednesday
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Mainly Sunny
23°C / 8°C

No significant precipitation is expected in Southern Manitoba on Wednesday, except again for the odd shower. Temperatures will be in the upper teens or lower twenties with mainly sunny skies.

Long Range

At this point the long range forecast is fairly ambiguous, as it often is at this time of year. In the nearer term, it appears we may experience another significant rainfall event later this week as a powerful low pressure system develops to our south. This system may trigger severe storms in the US Plains, while bringing us a bought of rainfall. In fact, this system is looking quite similar to the one that brought parts of Southern Manitoba 200mm of rain and triggered severe storms, including the Moore, OK tornado, in the US a week ago. There is still significant uncertainty in terms of how this next system will play out and at this time it isn’t expected to produce the massive rainfall amounts that the last one did. We’ll have more details on this system on Wednesday. What happens beyond the end of this week is too uncertain to discuss right now.