Category: Forecasts

Rain Brushes Southern Manitoba

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A powerful low pressure system drenching North Dakota and Minnesota will brush the southeastern portion of the province today. For the rest of us, fairly quiet weather will prevail with slightly below-normal temperatures.

Wednesday
17°C / 8°C
Mainly cloudy. Outside chance of some light showers.

Thursday
18°C / 6°C
Mainly sunny.

Friday
23°C / 13°C
Sunny, then increasing cloud late in the day.

The main weather story today will be the low pressure system working its way through North Dakota and Minnesota. Although this system will spread cloud through the entirety of the Red River Valley, rainfall will be constricted to the southeastern portion of the Red River Valley into SE Manitoba. At this point, it looks like the main area of rain will remain south and east of Steinbach. There’s a slight chance of showers backing into Winnipeg and the SW Red River Valley (Altona, Winkler), but if any precipitation managed to push that far north or west, it would remain very light.

Forecast rainfall amounts for the system clipping southeastern Manitoba through June 11th and 12th.
Forecast rainfall amounts for the system clipping southeastern Manitoba through June 11th and 12th.

Otherwise, it will be a mainly cloudy day with perhaps a few sunny breaks through the first half of the day. Winds will be a little breezy out of the north at 20-30km/h. Temperatures will top out around 17°C. Clouds will begin to push off to the east overnight, however the bulk of the RRV won’t see complete clearing until Thursday morning. Overnight lows will be near 8°C.

Cool But Pleasant End to the Week

Thursday and Friday both look to be quite nice, with temperatures some 5°C below normal returning to seasonal values. Thursday will see clearing skies as temperatures climb to 18°C. Winds will be light out of the north as a ridge of high pressure begins working its way eastwards into Manitoba. There may be a slight chance of some shower or thundershower activity over western Manitoba, but here in the Red River Valley things look sunny and dry. The overnight low on Thursday will generally sit around 6°C; this will likely be the coolest night for the next while.

Friday will be another mainly sunny day with warmer weather returning as the ridge of high pressure shunts off to the east and a southerly flow redevelops over the province. Under mainly sunny skies the temperatures will climb to near 23°C. Cloud will move into the Red River Valley late in the afternoon or the evening and the next system pushes into southwestern Manitoba. Temperatures will drop to around 13°C.

Unsettled Weekend

This weekend will be marked by unsettled weather as a major low pressure complex moves into Southern Manitoba and the Northern Plains of the United States. Rain, with the chance of thundershowers, will push into southwestern Manitoba on Saturday morning. There’s uncertainty as to what will happen after that, but at the time it appears that rain will likely slide eastwards along the international border through the day.

GDPS 24hr. precipitation amounts from Saturday evening to Sunday evening. The GDPS is forecasting 5-10mm of rain in the RRV for this period, with higher amounts west, south and east.
GDPS 24hr. precipitation amounts from Saturday evening to Sunday evening. The GDPS is forecasting 5-10mm of rain in the RRV for this period, with higher amounts west, south and east.

Afterwards, the general trend looks to be a shift northwards with the precipitation towards the northern Red River Valley, and then things push out late in the day on Sunday. Daytime highs on the weekend should rest in the low 20’s while overnight lows hover near the 11-12°C mark.

Fairly Normal Start to the Week

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This week will start out with fairly normal conditions for early June with a chance for rain, and moderate temperatures.

Monday will be a nice day in southern Manitoba
Monday will be a nice day in southern Manitoba

Monday

Monday
22°C / 13°C
Mainly sunny

Today may start out with a bit of rain in the morning as a piece of upper-level energy swings through but skies should quickly clear, making for a pleasant day. Any rain that does fall in the morning will be light, so it won’t be a big deal. By the afternoon we should see mainly sunny skies with temperatures in the low twenties and light winds.

Tuesday

Tuesday
23°C / 10°C
Chance of showers or thundershowers

Tuesday will see the chance for showers and thundershowers in the Red River Valley and south-eastern Manitoba ahead of an approaching trough. Any thundershowers that develop will present the risk of small hail and gusty winds. For those areas that miss out on the showers and thundershowers, it will be a nice day with temperatures in the low twenties and a breezy south-west wind.

Wednesday

Wednesday
19°C / 5°C
Mix of sun and cloud

A cold front will blow through southern Manitoba early Wednesday morning, setting us up for a slightly cooler day. Highs on Wednesday will be in the upper teens in most areas (perhaps a few readings in the low twenties), with skies being a mix of sun and cloud by the afternoon. The wind will be breezy and from the north.

Long Range

The long range forecast suggests we’ll continue to see normalish weather for the foreseeable future. That means high temperatures in the low to mid twenties and the frequent chance for rain or thunderstorms (albeit generally of the non-severe variety).

A Fairly Pleasant Weekend

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Although temperatures will be a little below normal for foreseeable future, a fairly pleasant few days are on tap for Winnipeg. A ridge of high pressure over the central Prairies will work at clearing out the clouds giving us plenty of sun for Friday and Saturday while winds slowly diminish. A low passing through on Sunday will mark the return of potentially rainy weather.

Friday
19°C / 7°C
Sunny with afternoon clouds. Breezy.

Saturday
18°C / 7°C
Mainly sunny.

Sunday
18°C / 8°C
Cloudy periods with a chance of showers.

Significantly cooler air than seen over the past week is working its way across the Prairies into Southern Manitoba, dropping daytime highs from the the mid-to-high 20s to the high teens. Temperatures will remain roughly 5°C below normal for the next week as a much cooler pattern locks in; daytime highs aren’t expected to reach over 20°C until late into next week.

Today will bring some late morning/afternoon cloud with a breezy west-to-northwesterly wind at around 20-30km/h. Temperatures will reach around 18°C. Expect clearing skies tonight and a low of around 7°C.

Tomorrow will be very similar to today except with a little less cloud and lighter winds. High near 18°C once again and a low near 7°C again.

Showery Sunday?

A weak low pressure system is forecast across Southern Manitoba on Sunday, bringing a renewed chance of showery weather. At this point, it looks like little in the way of particularly active weather will occur; even a rumble of thunder looks out of the question.

Probability matched mean precipitation from the SREF model for Sunday morning.
Probability matched mean precipitation from the SREF model for Sunday morning.

In general, the system is expected to spread some light shower activity from west to east across Southern Manitoba through the morning hours, persisting into the afternoon. Overall amounts look to be low; in the image above, I’ve used a probability matched mean ensemble[1] which can better capture higher amounts embedded within the mean precipitation field, and it still only shows around 2-4mm for most areas.

There are some hints the system may pick up strength and produce 5-10mm over the woods from Pinawa down to Sprague, but it’s still a little too far out to say much reliably.

Sunday won’t be all showers and cloud, though with a good chance of a few sunny breaks through the day. Highs will be near 18°C once again with an overnight low around 8°C.

Heading into next week it looks as if the cooler temperatures will continue with a couple more chances for precipitation through the first half of the week.

  1. For those who are curious, this takes the ensemble mean value, but matches the rain rate distribution in the ensemble mean field to the complete ensemble. Can help prevent “smearing” of the precipitation field.  ↩

Sunshine Gives Way to Unsettled Weather

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The beautiful summer weather will stick around for one more day before a large upper trough pushing across the Prairies spreads showers and generally unsettled weather into Southern Manitoba.

Forecast precipitation for Wednesday night from the RDPS.
Forecast precipitation for Wednesday night from the RDPS.

Today will be an almost ideal summer day across much of the Red River Valley. Sunny skies will gradually see increasing cloudiness through the afternoon hours, however before things cloud up temperatures will climb all the way up to around 27 or 28°C while light winds begin picking up in the afternoon to 20-30km/h.

Wednesday
27°C / 14°C
Increasing cloudiness in the afternoon.

The story will be a little different over southwest Manitoba today, where an incoming surface trough will combine with warm weather and moderate instability to produce mid-to-late afternoon thunderstorms. Around 1250J/kg of CAPE will combine with 25kt of bulk shear and a 25-30kt LLJ to support upscale growth from a few isolated thunderstorms to an eastward moving line by the evening. This line will weaken fairly quickly as it moves into the Red River Valley thanks to the loss of daytime heating and the storms moving away from their main support.

The overall threat of severe weather in southwest Manitoba is marginal. The main risks will be large hail, but that seems like a fairly off chance at best. A rogue wind gust can’t be ruled out either, but again, I don’t have particularly high expectations for severe weather. Were I the SPC, it would be a “See Text” sort of day.

This line will bring a chance of showers or thunderstorms to Winnipeg and the Red River Vally through the overnight hours. No severe weather is expected. Temperatures will drop down to around 15°C or so.

Thursday & Friday

Thursday
25°C / 10°C
Cloudy periods; slight chance of showers.
Friday
21°C / 8°C
A mix of sun and cloud.

Tomorrow will bring cloudy periods with a slight chance of showers through the day. The precipitation risk will increase towards evening as a second impulse digs the upper trough into Manitoba, leaving us with a chance of showers on Thursday night.

Cooler air will also start filtering in. Thursday’s high of 25°C will be replaced by cooler weather for the remainder of the week and weekend. The temperature will drop to around 10°C on Thursday night.

Things should push off to the east on Friday morning leaving behind some sunny skies, but skies look to become mixed midday. There may be a chance of seeing some rain on Friday afternoon, but guidance is very mixed right now as to whether or not a band of rain will push northeastwards out of North Dakota. At this point it seems more likely that things will stay dry than not. We’ll see highs across the Red River Valley top out around the 21°C mark. The overnight low on Friday night will drop into the high single digits.

The Weekend

The weekend across the Red River Valley is looking fairly nice, albeit a little cool. Saturday will see afternoon cloudiness bring a slight chance of late-day showers. Sunday looks fairly sunny, although cloud will likely increase in the evening ahead of another system forecast to push through the region on Monday. Highs will sit near the 20°C mark with overnight lows in the mid-to-high single digits.