May Showers on Tap this Week

Scott Leave a comment

After last week’s record breaking heat and overall sunny conditions, our soggy April has quickly turned into a dry May. This week should finally feature some much needed rain, although how much remains to be seen.

Today will be our last hot, sunny day before cooler and greyer conditions build in for the rest of the week. Temperatures are expected to reach the mid twenties over southern Manitoba with a breezy south wind. Skies will likely remain somewhat hazy as smoke from the forest fires over Northern Alberta continues to linger. Enjoy what could be the last hot day for awhile!

Today will feature warm weather once again in southern Manitoba, but low pressure to the south will bring rain on Tuesday and Wednesday.
Today will feature warm weather once again in southern Manitoba, but low pressure to the south will bring rain on Tuesday and Wednesday.

Tuesday will remain mild, but some rainfall is expected as a strong low pressure system pushes up from the south. Showery rains are expected throughout the day, although it will be hard to make an accurate forecast for how much rain will fall. At this point it appears that 2-6 mm is a reasonable range, although some areas may see no rain, while others see more than 6 mm. Winds will be south-easterly at 30 km/h gusting to 50 km/h, while temperatures sit in the upper teens.

Wednesday will see the low pressure system from Tuesday continue to stick around and bring more rain to southern Manitoba. Accumulations of 2-6 mm will be possible once again on Wednesday, with the same caveat that amounts will vary on a localized basis. Temperatures will remain in the upper teens, with southerly winds of 20-30 km/h.

Long Range

It appears that the rest of this week will be on the cooler side as we experience a brisk northerly flow behind the low pressure system that brought us the rainfall. Models suggest that the remainder of the first half of May will stay normal to below normal in terms of temperature, before warmer conditions return again for the second half of May. Most long range/seasonal guidance suggests that this summer will generally be warmer than normal, although it is notoriously difficult to predict summer weather in the long range!

Cooler Temperatures On The Way, But Still Above Normal

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A cold front sweeping through Southern Manitoba this morning will bring an end to the incredible heat that baked the province yesterday and shattered numerous record high temperatures. What moves in behind the front can hardly be called cold, however, as above-seasonal temperatures continue in the region for the coming several days.

May 5th: Records High Temperatures Shattered Across The Province

A very hot and dry air mass moved into Southern Manitoba yesterday and, somewhat predictably, resulted in numerous new record high temperatures as records were broken all over the place. This air mass had broken essentially every single high temperature record in Saskatchewan the prior day[1] and was the source of numerous record high temperatures in Alberta, exacerbating the fire situation that has resulted in one of the largest wildfire disasters[2] in Canadian history in Fort McMurray.

Time-series of Winnipeg's Temperature & Dewpoint on Thursday May 5, 2016
This graph of Winnipeg’s temperature clearly shows the very rapid warm-up on Thursday morning.

Temperatures rocketed up early Thursday morning with many places reaching 30°C by midday, and by mid-afternoon temperatures of 32-34°C were commonplace over the region. These very warm temperatures resulted in a large number of record high temperatures being broken:

Record High Temperatures Set on May 5, 2016
Location May 5th High Previous Record
Brandon 34.3°C 31.7°C (1934)
Dauphin 34.4°C 31.7°C (1918)
Fisher Branch 34.5°C 25.5°C (1987)
Gimli 33.8°C 26.3°C (1987)
Gretna 35.1°C 26.0°C (2000)
Melita 33.3°C 28.2°C (1993)
Pilot Mound 33.3°C 27.8°C (1939)
Pinawa 32.0°C 27.0°C (1987)
Portage La Prairie 34.2°C 31.7°C (1918)
Sprague 33.6°C 32.8°C (1939)
Swan River 34.5°C 30.0°C (1911)
Winnipeg 35.2°C 31.7°C (1926)

Winnipeg’s official high of 35.2°C marked the earliest date for a temperature 30°C or higher, beating out the more than 140 year old record of May 8th, 1874. Additionally, the difference between yesterday morning’s low of -2.4°C and today’s high marks the 3rd largest spread between a daytime high and the previous day’s overnight low since record began in 1872.[3]

Windy Friday Followed by a Pleasant Weekend

Today will see fairly windy conditions behind the cold front that will sweep through this morning. Gusty winds will strengthen out of the northwest to 40-50 km/h behind the front as temperatures head towards a high of 19°C. Skies will be mixed, but no precipitation is expected.

Winds will taper off this evening as temperatures head towards a low near 6°C under mainly clear skies.

RDPS 10m Wind & MSLP Forecast – Valid 15Z Friday May 6, 2016
Moderate northerly winds are expected to pick up Friday morning behind a cold front moving through the region.

The weekend will be fairly pleasant with mild temperatures as highs on both Saturday & Sunday climb into the low 20’s. Saturday will still be a bit wind with northerly winds to 30-40 km/h, however they should ease for Sunday. Skies will be fairly sunny throughout the weekend with no chances for precipitation!

Long Range: Some Rain? Maybe?

Temperatures will continue at near-to-above seasonal heading into next week, with some hints that the weather may become more unsettled.

The general trend in the models is to introduce a very large, slow-moving upper trough early next week over the west coast and to have it gradually move eastwards. Precipitation patterns at this point appear convectively driven over small regions, but also slow-moving which means that moisture may become feast or famine next week. The last thing moisture-strained regions of the Prairies need is prolonged periods of heavy rain, so we’ll be keeping a close eye on how the forecast of this system changes as it approaches!

Winnipeg’s seasonal daytime high is currently 17°C while the seasonal overnight low is 3°C.

  1. The bulletin issued by Environment Canada:

    A SOUTHWEST FLOW OF VERY WARM AIR OVER THE PRAIRIES HELPED TO SET NEW RECORD HIGHS AT VIRTUALLY EVERY REPORTING SITE IN SASKATCHEWAN TODAY, MANY WITH LONG STANDING RECORDS. THE FOLLOWING ARE DAILY RECORD HIGH TEMPERATURES SET TODAY MAY 4TH AT ENVIRONMENT CANADA MONITORING STATIONS, 27 IN TOTAL.

    Saskatchewan Record High Temperatures Set on May 4, 2016
    Location May 4th High Previous Record
    Assiniboia 30.2°C 28.3°C (1918)
    Broadview 29.7°C 27.2°C (1918)
    Buffalo Narrows 30.0°C 26.0°C (1992)
    Collins Bay 22.5°C 21.5 (1987)
    Elbow 31.0°C 27.2°C (1918)
    Estevan 30.1°C 30.0°C (1939)
    Hudson Bay 31.1°C 25.6 (1987)
    Key Lake 28.1°C 22.0 (1987)
    Kindersley 29.0°C 28.9°C (1918)
    La Ronge 33.2°C 24.8°C (1987)
    Leader 31.2°C 29.4 (1936)
    Maple Creek 29.2°C 27.8·C (1936)
    Meadow Lake 32.3°C 26.1°C (1992)
    Melfort 32.4°C 27.2°C (1918)
    Moose Jaw 31.8°C 31.7 (1918)
    Nipawin 32.8°C 31.1°C (1949)
    North Battleford 31.1°C 27.2°C (1897)
    Prince Albert 32.4°C 27.8 (1918)
    Regina 31.4°C 29.4°C (1918)
    Rosetown 31.7°C 27.5°C (1992)
    Saskatoon 32.6°C 30.0°C (1918)
    Stony Rapids 27.7°C 22.0°C (1987)
    Swift Current 29.3°C 28.9°C (1918)
    Watrous 32.3°C 26.1°C (1977)
    Weyburn 29.9°C 27.3°C (1926)
    Wynyard 30.6°C 25.6°C (1987)
    Yorkton 30.5°C 30.0°C (1930)

     ↩

  2. At least with respect to the human impact.  ↩
  3. Thanks to AWM contributor Julien for digging those stats up.  ↩

The Heat Ramps Up

Brad 1 Comment

Temperatures are set to soar way above seasonal values in Southern Manitoba over the next couple days as a dry & unseasonably warm air mass over Alberta pushes into the province. Temperatures will soar on Thursday above 30°C, likely breaking several record high temperatures for that day across the province.

The heat is on as warmer weather begins pushing eastwards out of the western Prairies and spreading into Manitoba. Temperatures in Winnipeg today will climb to a mild 21°C with relatively light winds out of the south and a few clouds through the afternoon hours. Through the remainder of the Red River Valley, temperatures will be in the 18-22°C range with light winds as well. It will be milder over southwestern Manitoba with a slight southwesterly breeze and highs in the 23-26°C range.

Winds will begin picking up out of the southwest to 20-30km/h tonight as even warmer air begins moving into the region. This will keep overnight lows quite mild at just 13-14°C over the central & eastern Red River Valley. Over the western Red River Valley, overnight lows will be even milder at 15-16°C, bolstered by the down-sloping winds off the western escarpment.

RDPS Forecast 2m Temperature – Valid 21Z May 5, 2016
The RDPS is forecasting temperatures near or above 30°C over a wide swath of the Prairies on Thursday

Thursday will be a scorcher as the core of the warm air moves over the region. Temperatures will soar into the low 30’s with winds out of the west at 20-30km/h. The breezy winds, hot temperatures and low humidity will present an elevated fire risk, so it will be important to follow the latest fire guidelines issued by the province. Skies will be mainly sunny. Temperatures will remain mild on Thursday night with overnight lows dipping to just the mid-teens. With a high near 32°C, Winnipeg will challenge its record high temperature for May 5, which currently is 31.7°C set in 1926.

A cold front will sweep through the province on Friday, ushering in strong northwesterly winds and cooler temperatures. A few showers are possible, but with such limited moisture available and the poor timing of the frontal passage, I don’t expect Winnipeg to see any precipitation. Temperatures will reach a daytime high near 19-21°C before the cooler air begins moving in. Winds will strengthen to 40 gusting 60 km/h out of the northwest by midday. Winds will taper off on Friday night as temperatures head to a low near 8°C.

Long Range

Warm weather will return for the weekend with temperatures climbing back into the low- to mid-twenties under mostly sunny skies. A more southerly feed will mean that it won’t be quite as dry as this week’s warm weather, but the lack of rain continues.

Temperatures will continue mild into the beginning of next week. Some cooler weather is possible into mid-week as alongside the potential for some precipitation across the region, but at this point, it’s far to early to address that potential.

Winnipeg’s seasonal daytime high is currently 17°C while the seasonal overnight low is 3°C.

Beautiful Start to May

Scott Leave a comment

May is getting off on the right foot, with sunny skies and mild temperatures expected this week. No major precipitation is expected either, helping to continue the drying process after our heavy April rains.

Today will be one of the warmest days of the year thus far, as temperatures climb above the 20C mark. High temperatures in the 21-23C range are generally expected. Skies will be mainly sunny, with only some light upper cloud cover rolling through. Light winds and dry soil should develop superadiabatic profiles near the surface, helping to ensure we warm as much as possible today. There isn’t much else to be said about today’s conditions, so enjoy it!

Very pleasant conditions are expected in southern Manitoba today
Very pleasant conditions are expected in southern Manitoba today

Tuesday will feature a slight cool-down as a cold front passes through early in the morning. You’ll notice that this front has passed because winds will be brisk throughout the day, with speeds of 40 km/h gusting to 60 km/h out of the north. Temperatures won’t drop too much though, with highs still expected to be in the mid teens under sunny skies.

Wednesday will see temperatures hovering in the mid teens once again, but the gusty winds from Tuesday will have died down. Skies are expected to remain sunny as we will be under the influence of a surface high pressure system.

Long Range

Long range models suggest that the first half of May will generally see above-seasonal temperatures. A large upper ridge is expected to remain over Western Canada, helping to keep our skies sunny and temperatures mild. There is no indication yet about how the second half of May will fare, but it appears the month as a whole will end up being warmer than normal.