We are putting out this week’s forecast a day earlier than usual, as the weather models now have a good handle on the predicted Colorado low and how it will impact the Prairies starting Tuesday. Here is what the weather models are predicting.
As of Tuesday morning, the low will be beginning to move northeastwards out of Colorado. The low has already developed an inverted trough that stretches all the way into northeastern Alberta and northwestern Saskatchewan. The main low is forecasted to take a much more southern track than originally forecasted, with the center of circulation tracking through southern Minnesota on Wednesday.
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The inverted trough is forecasted to hang back from the main low and will be the focus of most of the precipitation across the Prairies over the next several days. It looks like most regions will start with rain on Tuesday and Wednesday before colder arctic air gets pulled southwards on the back side of the system. Light snow and flurries are expected on Thursday and Friday. Things should then clear out over the weekend, with temperatures slowly warming under strong spring sunshine.
Alberta
It looks like nearly all regions will feel the direct impact of the inverted trough stretching northwest out of the Colorado low on Tuesday. With Alberta starting off on the back side of the trough, cold air is already working its way southwards. Daytime highs are forecasted to be in the 0 to +4 C range on Tuesday. Expect a mixed bag of precipitation, as type and amount are difficult to pinpoint.
It looks like the trough will move off east sometime on Wednesday as Arctic high pressure drops southwards. This high will bring sunny to partly cloudy skies and cold temperatures. Expect daytime highs from Thursday to Saturday in the +2 to +5 C range with overnight lows falling into the -6 t0 -10 C range.
As the high drops south and eastwards over the weekend, warmer air will move back in as the flow becomes more westerly. Expect daytime highs back in the low teens with overnight lows warming to around +3 C. The models are forecasting a weak low tracking eastwards in the westerly flow early next week. Exact timing of this system is tough, but expect a bit more clouds early next week—especially over southern and central regions. An odd scattered shower is possible.
Saskatchewan and Manitoba
Both regions will see rain develop during the day on Tuesday. The best chances of steady rain is forecasted to be along the main trough line, which looks to lie over eastern Saskatchewan and western Manitoba. The northern half of both provinces are expected to see more snow than rain, but the exact rain-snow line is a little uncertain at this time. Temperatures over southern regions will be relatively mild on Tuesday with daytime highs in the low to mid-teens and overnight lows falling to around +5 C.
The southern part of the trough will slide eastwards on Tuesday and Wednesday as the northern end stalls out over north-central Saskatchewan. As the trough pulls through southern Manitoba, and the main low tracks by to the south on Wednesday, southern and eastern regions of Manitoba are expected to see steady rain.
Across southern and central Saskatchewan, the rain should change to light snow or flurries late in the day as cold air get pulled southwards behind the trough. This cold air will begin to work into Manitoba over night Wednesday or early Thursday, turning the rain into snow at some point. Again, exact timing of the change over is a little uncertain at this time. Current indications are that most of the precipitation will fall as rain with only light snow accumulations expected.
As the main low continues to track eastwards into Ontario, the trailing trough will slowly weaken and will eventually get pulled east by late Friday or early Saturday. Most areas will continue to see cloudy skies with occasional flurries on Thursday and Friday before things finally clear. Daytime highs will only be in the +2 C range with overnight lows falling to around – 5 C—colder if skies clear. Warmer air should begin to move in over the weekend with daytime highs by Sunday expected to be back into the low teens.
The first half of next week looks clear and seasonably mild across central and northern regions. A weak area of low pressure is forecasted to move across the southern prairies during this period , which should bring a mix of sun and clouds. Confidence in this system is low at this point.
—Headline updated 4:20, April 16.
