Ag Weather Forum

Prairies to See Large Temperature Swings

By Doug Webster , DTN Senior Ag Meteorologist

Temperatures across parts of the eastern Prairies have been going through some large swings during the past day or two as a battle between Pacific and arctic air takes place. Given the evolving weather pattern during the next week we should get used to seeing some large day-to-day changes in temperature with the emphasis on the eastern Prairies while warmer Chinook winds may be more dominant for the west.

A gradual return of a weather pattern like we observed during December and early January appears quite likely across Canada, but with the core of the cold air a little further east than the early winter regime. The reason is that it looks like the polar vortex will set up shop near or a little east of Hudson Bay later this month rather than across the northwest portion of Ontario as it was earlier in the winter.

Still dominant will be a strong ridge along the west coast of North America and this time it will have a little more influence on the western Prairies by allowing for warming Chinook winds while arctic cold may build into Manitoba at times. This pattern may lead to some rather extreme temperature differences from east to west with readings possibly -20 C (-4 F) and below for Manitoba and readings as high as 10 C (50 F) across Alberta on the same day.

Also likely are more of the day-to-day flipping of temperatures from quite mild to bitter cold for some central and eastern Prairie areas. Some of the fast-moving clipper storms moving through the region during the next 10 days will create periods of strong winds, possibly in the damaging category, as some of the jet stream winds aloft are mixed down to the surface. Chinook winds are noted for being strong at times with the Canadian Rockies helping to bring the strong winds aloft toward the surface as the winds rise over the mountains and then come down on the east side. These winds are also usually precipitation free.

The reasons behind the temperature instability is that the store of arctic air across the eastern half of Canada will make pushes into the eastern and sometimes central Prairies from the east and northeast, while areas to the west stay in the Pacific flow of mild winds. This is a bit different than earlier in the winter when all areas shared in the extreme cold. There are some signs that with time, mostly beyond a week from now, that the arctic cold may overspread all of the Prairies once again.

As the polar vortex returns and reorganizes across eastern Canada during the remainder of the month, we will see potential of more extreme cold for central and eastern Canada and some of this could have eyes on the more eastern portions of the Prairies.

Precipitation prospects with a weather pattern like we expect usually are light. Most precipitation comes with any fast-moving clipper systems and should fall mostly on the cold side of the track of such storms. That would imply that the eastern and northeastern Prairies will be more prone to a few periods of light snow once in a while, but Alberta stays mostly dry.

The upcoming dry conditions should not yet be of concern for those wondering about spring planting. An above-normal snow pack currently exists across much of Western Canada due to the heavy snows of December and this may initially help out with soil moisture early in the spring. If we continue to see dry weather as we move into the late winter and spring, there could be some increased concern as to how much soil moisture will be available for spring planting.

Doug Webster can be reached at



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