We are starting to see a shift in the general weather pattern across much of Canada, but I’m not sure if this is really a fundamental change in the pattern or the pattern simply adjusting to the changing season.
For this forecast period we’ll see a bit of a battle between a ridge of high pressure over western North America and a trough of low pressure over east-central North America. Right now it looks like Manitoba will be stuck on the dividing line between these two features, meaning this could be a tough forecast to figure out. Weather models show the western ridge weakening mid-week, as an area of low pressure tracks across the northern Prairies. This will mean cool conditions on Wednesday and Thursday along with a mix of sun and clouds. The western ridge then looks to rebuild during the second half of the week and we should see temperatures warm back into the low 20s by Friday. Saturday should continue on the warm side before the central North American trough deepens, bringing cooler conditions on Sunday.
This upper trough looks as if it will be in control for at least the first half of next week. This will mean fairly cool temperatures, with highs only in the mid-teens and overnight lows in the 3 to 5 C range. It doesn’t look right now as though there will be any widespread frost — but if there is any frost, the best chance will probably be Tuesday or Wednesday morning. Most days will probably start off with plenty of sunshine, but with cold air aloft and daytime heating we’ll likely see afternoon clouds.
The western ridge looks as if it will rebuild eastward during the second half of next week. If this happens we should see temperatures warm back up into the low 20s.
Usual temperature range for this period: Highs, 13 to 24 C; lows, 1 to 11 C.