Highlights
- The Prairies should see a couple more days of warm, summery temperatures
- The influences of two lows should bring cold weather over the weekend, or early next week
- A Colorado low, if it develops as predicted, could bring significant rain to southern Manitoba and eastern Saskatchewan
Once again, the weather models did a pretty good job with the weather forecasts. While some of the finer details might have been a bit off, the models got the over all pattern correct. The only error, if you want to call it an error, was under-forecasting the temperatures.
The big question leading into this forecast period is — just how long will the summery temperatures will continue? After all we are now into October.
Overview
We start this forecast period with high pressure over eastern Canada, which is helping to keep an upper ridge over Manitoba. Across Saskatchewan, we have an area of low pressure lifting northeastwards. Meanwhile, a stubborn area of low pressure remains stationary off the coast of southern B.C.
The combination of the low, which is lifting to the northeast, and the stationary low off the B.C. coast will allow for weak upper level ridging to build across the Prairies during the second half of this week. This means a continuation of above average temperatures.
As the B.C. low weakens over the weekend, two areas of low pressure look to work together to bring an end to the summer-like temperatures we’ve seen across the Prairies.
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The first low will track across northern Canada and will drag a cold front southward. A second area of low pressure is forecasted to develop over Colorado – heck, I guess we can say it is the seasons first Colorado low of the season! This low is forecasted to lift northeastwards into southern Manitoba by Sunday and will bring a good chance of rain.
The counterclockwise rotation around the low will also help to drag down cold Arctic air that was already pushing southwards behind the northern Canada low. This will result in colder than average temperatures flooding across the Prairies on Sunday and Monday.
Currently it doesn’t look cold enough for precipitation to fall as snow.
The Colorado low is forecasted to push into Hudson Bay by Monday with high pressure building across the Prairies. This pressure gradient will make for windy and cool conditions across Manitoba and eastern Saskatchewan, while upper-level ridging will bring a return to warm temperatures over western Saskatchewan and Alberta.
Alberta
It looks to be another dry forecast period as the main storm track remains either well to the north or to the east. Expect temperatures to slowly cool during this forecast period as two areas of low pressure interact to bring colder air southwards.
The first low is forecasted to track across northern Canada on Wednesday and Thursday, which will push a cold front southward. While this front will not make many inroads, a second area of low-pressure lifting northwards into Manitoba over the weekend will help to pull it southwards.
High temperatures by Monday will only reach into the low teens. Overnight lows are expected to be near to below zero across central and northern regions with southern areas falling into the 0 to 5 C range.
Cold air will remain in place until at least Tuesday before a building ridge of high pressure brings a return of above average temperatures. Expect daytime highs to moderate into the upper teens to around twenty degrees by Wednesday.
Saskatchewan and Manitoba
As the main area of low pressure lifts northwards through Saskatchewan on Wednesday, except sunny to partly cloudy skies along with the chance of showers or thundershowers across southern Saskatchewan and Manitoba. Temperatures will remain well above average thanks to a strong southerly flow ahead of the low.
Temperatures will cool down behind the low across Saskatchewan on Thursday while southern Manitoba looks to see one more day of well above average temperatures.
Over the weekend, the weather models show a strong area of low pressure developing over Colorado and then lifting northeastwards into southern Manitoba by Sunday. While confidence is low at this time, should the low materialize as forecasted, southern regions of Manitoba and eastern parts of Saskatchewan could see significant rainfall with amounts of 20 to 30 mm possible in some areas.
Cold air will wrap southwards behind this low late on Sunday and into the first half of next week. Expect overnight lows to be in the 0 to 4 C range with daytime highs only in the 8 to 12 C range.
