The first half of last week’s forecast played out as expected. Fortunately, the second half didn’t materialize, thanks to a northward shift in the overall pattern.
Spring and fall tend to be the toughest times to forecast the weather as the atmosphere begins its transition between summer and winter weather patterns, and we saw this with the weather models last week. The predicted outbreak of arctic air was cut off by a faster and more northerly storm track. This shift allowed for our summer pattern of weak upper ridging to rebuild across central North America, bringing with it relatively warm and dry weather.
This forecast period will begin with the area of high pressure that brought our first widespread killing frost to begin the week moving off to the east. We will also see an area of low pressure begin to gather strength and deepen over Montana. The flow between these two systems will help keep temperatures at or even above the usual temperature range for this time of the year on Wednesday and Thursday. The Montana low is then forecast to track across north-central Manitoba on Friday. Far northwestern areas may see the odd shower with this system, while more southern regions should see more sun than clouds.
Once this system pushes through we’ll see cool high pressure build in that will help to return temperatures back to more average values over the weekend. The weather models then show another area of low pressure tracking quickly across northern Manitoba on Monday. This will place southern and central regions in the warm sector. Expect mainly sunny skies with temperatures in the mid-teens. Cooler air will work back in by Tuesday, but it looks like the cool weather will be short lived as we’ll see more mild air moving back in for the second half of next week.
Usual temperature range for this period: Highs, 6 to 18 C; lows, -4 to +6 C.