Cool Wednesday Just A Speed Bump; Warm Weather Quickly Returns

Today will be a rather cloudy, cool and unsettled day across the Red River Valley as a trough of low pressure swings through the region. The wet weather will be short-lived, though, and there will be a quick return back to sunny and warm weather.

The wet weather moved in overnight and will taper off this morning, leaving mostly cloudy skies until sometime in the afternoon when some sunshine will begin breaking through. Temperatures will be cool for mid-August with a high of just 23°C. There will be a slight chance of a shower or thundershower this afternoon if enough sunshine pops out and warms things up even a little bit more than expected.

The cloud will clear out in the evening, leaving Winnipeg with clear skies as temperatures head to a low near 13°C.

RDPS 3hr. Precipitation Totals valid 18Z Wednesday August 16, 2017
The RDPS shows the main area of rain tapering off before 10AM across the Red River Valley.

Thursday will bring summer weather back to Winnipeg. Aside from a bit of morning low cloud or fog, skies will be partly cloudy with temperatures rebounding back towards a high near 27°C. Some cloud cover will begin working into the region in the evening ahead of an incoming low pressure system. This system will spread scattered showers into southwestern Manitoba overnight as it slowly moves east-southeastwards, but should remain west of the Red River Valley. Temperatures will dip to a low near 15°C under mixed skies on Thursday night.

RDPS 24hr Precipitation Totals valid 00Z Saturday August 19, 2017
The GDPS shows the potential for wet weather across portions of the Red River Valley on Friday.

Friday will continue to be warm, but skies will be mixed as a low pressure system passes to the south of Winnipeg. Highs near 28°C combined with the low moving through will bring showers and the risk of thunderstorms to the Red River Valley. Depending on the exact track of the low, everything may end up to the south of Winnipeg, but at this point there’s still enough of a chance of seeing something here that it’s worth mentioning. Things will clear out for Friday night as temperatures head to a low near 15°C.

Long Range

Once we get past Friday’s weak disturbance moving through the region, things turn more settled once again with generally warm and dry conditions. Daytime highs will climb to the upper 20’s through the weekend with overnight lows continuing in the mid-teens. The start of next week continues to look nice with warm, dry conditions expected.

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.

Cloudier Conditions Follow A Sunny & Warm Monday

Winnipeg has seen an abundance of sunshine lately, but it comes to an end on Tuesday as extensive cloud cover moves into the region ahead of a low pressure system that will bring unsettled weather to the region.

Before the cloud moves into the region, Winnipeg will get another beautiful day today with plenty of sunshine and highs approaching the 30°C mark. Winds will remain light through the day and the humidity will still be quite comfortable. All in all a great summer day.

RDPS 2m Temperature forecast valid 21Z Monday August 14, 2017
Highs across much of Manitoba will climb into the upper 20’s or low 30’s on Monday.

Clouds will move in on Monday night as temperatures dip to a low near 15°C and the winds become light out of the south.

Tuesday will bring mostly cloudy skies to Winnipeg with winds picking up out of the south to 20-30 km/h. Scattered showers or thunderstorms are likely over the southwest corner of the province, but things should stay dry in the Red River Valley. Expect cloudy skies on Tuesday night with a low near 17°C and a slight chance of showers.

RDPS 12hr. Precipitation Totals valid 00Z Wednesday August 16, 2017
An area of showers and/or thunderstorms will move into southwestern Manitoba on Tuesday evening.

Wednesday will bring slightly cooler temperatures to Winnipeg as highs reach just around 23°C under cloudy skies. There will be a good chance of showers, particularly through the morning hours. Winds will be out of the east at around 15-25 km/h. Conditions will slowly settle through the afternoon and there may even be a few sunny breaks. Expect the clouds to clear out on Wednesday night as temperatures dip to a low near 15°C.

Long Range

Once this system moves out, it looks like another long stretch of warm and dry conditions. Thursday through next Tuesday looks warm with highs around the 27 or 28°C mark with plenty of sunshine. A couple disturbances will move through over those days and bring a low chance for some thunderstorms, but at this point models disagree significantly on their placement and how much, if anything, they’ll be able to produce. We’ll be keeping an eye on it and have more details in Wednesday’s forecast post.

Winnipeg’s seasonal daytime high is currently 25°C while the seasonal overnight low is 12°C.

July Finishes Slightly Cool with Near-Normal Rainfall

July 2017 spent much of it’s time with below normal temperatures — 16 of 31 days had daily mean temperatures below the 30-year average — but was still generally pleasant with much fewer days of rain than in June and many daytime highs that were close to seasonal values.

The first third of July consisted of a swing from well below-normal temperatures to well above normal temperatures followed by a brief period of near-normal temperatures. The deviations from normal more-or-less cancelled each other out with a month-to-date departure from normal of -0.2°C by July 10th. For the next 14 days, though, Winnipeg fell into a prolonged period of below normal temperatures with daily means generally 1.5 to 2.5°C below normal. By July 23rd, Winnipeg’s month-to-date departure from normal had fallen to -1.2°C. The end of the month saw an abrupt turnaround, though, as hot and humid weather moved into the region. Several days saw high temperatures in the upper 20’s to low 30’s and overnight lows in the mid- to upper-teens.

No record temperatures were set in July, however.

By the end of the month, the warm spell had allowed the monthly mean temperature departure from normal to recover to -0.4°C.

In other temperature statistics:

  • July 2017’s average high temperature was 25.7°C, just -0.1°C below the 30-year average of 25.8°C.
  • July 2017’s average low was 12.5°C, -0.8°C below the 30-year average of 13.3°C.

Near-Seasonal Rain at the Airport

While there was only rain on 8 of 31 days in July, total rainfall ended up near-normal with 71.1 mm.

While it rained infrequently, the Winnipeg airport measured a total of 71.1 mm of rain through July 2017, 90% of 30-year normal of 79.5 mm. Much of the rain fell on just 3 days: July 11 (21.7 mm), July 21 (14.1 mm), and July 22 (14.3 mm). The combined 3-day total of 50.1 accounted for 70% of the month’s rainfall.

The 8 days of measurable precipitation was a welcome improvement from June which saw 14 days of measurable precipitation. The concentration of the bulk of the rain into just 3 days did make for some drying, though, and some gardeners likely needed to begin watering their plants occasionally again.

It is worth noting, however, that rainfall was variable throughout the city. At my Glenwood personal weather station I measured slightly less at 68.6 mm. Some locations over south and eastern Winnipeg saw as little as 50-55 mm while other locations across the west side of the city saw up to 85 mm.

So in the end, July 2017 was a very nice rebound from June. There were few days with rain, quite a few days with near-seasonal highs and a lack of humidity that brought more frequent slightly below-normal temperatures at night.

August seems to be continuing the trend so far with near-seasonal highs and cooler nights courtesy a lack of humidity. No complaints from this author!

Unless otherwise noted, all normal values referred to in this post use the 1981-2010 normals for Winnipeg, Manitoba.

Warm and Dry Weather Ahead

An upper-level ridge slowly building eastwards across the Prairies will bring generally sunny and increasingly warm weather to Winnipeg and the Red River Valley. For those who like summer weather, the next 5 days will be pretty much perfect!

The upper-level ridge that has been anchored over British Columbia over the past week will begin pushing eastwards, shifting the omega block pattern from the west coast to over the Prairies. This will spread mild weather over the Prairies and, eventually, break the persistent northerly winds that have been in place over the province and return a southerly flow that will bring humid conditions back to the region next week.

GDPS forecast 500mb heights and height anomalies valid 18Z Sunday August 13, 2017 with weather feature annotations.
By Sunday, the omega block will be situated over the central Prairies, however parts of Southern Manitoba will see some cloud as an upper low tracks through North Dakota.

So, for the coming few days, the forecast will be straightforward with daytime highs of 26 or 27°C and overnight lows in the 13-15°C range. Winds will be light over the next 3 days and there will be plenty of sunshine. Sunday may bring a few more clouds as an upper-level low passes by to our south, but even then we expect things to remain dry.

Long Range

Looking into the beginning of next week, things start off quite warm with highs climbing into the upper 20’s and overnight lows creeping up into the high teens. A trough of low pressure will begin building across the Prairies Monday night, bringing southerly winds into the region on Tuesday that will gradually ramp up the humidity. As it stands now, it appears that by the end of Tuesday dew points will climb to around 17°C, bringing slightly muggy weather back to the region.

A chance of showers or thunderstorms then returns to the region on Tuesday night into Wednesday and marks the transition into a few days of potentially unsettled weather. Temperatures will remain warm, though with highs continuing in the mid- to upper-twenties.

Winnipeg’s seasonal daytime high is currently 26°C while the seasonal overnight low is 12°C.