Forecast: A battle between high and low pressure

Issued September 19, 2016 – Covering the period from September 21 to September 28, 2016

Fall is usually a tough time of year to forecast as we begin our shift from summer to winter. This year looks like it might be tougher than most, since our summer weather pattern was pretty unpredictable. We saw a little of this last week. The storm system that was forecast to track by to our south late last week did exactly that, but the moisture associated with it pushed farther north than expected, bringing isolated significant rains. Over the weekend a large low moved through Northern Canada a couple of days earlier than forecast, bringing clouds and showers for the first half of Sunday.

Related Articles

This forecast period looks like it will turn out to be a battle between cool high pressure to our north and a strong area of low pressure to our southwest. The weather models have been bouncing around on which feature will win out over our region. The latest models show an area of high pressure building into our region on Wednesday, bringing sunshine and seasonable temperatures. This high will slowly move off to the east by Friday as a strong Colorado low develops and begins to move northeast.

We’ll likely see clouds increasing late on Friday, with showers and even some thundershowers moving in from the south on Saturday. These showers could transition to steady rain by Sunday depending on the track and the strength of the low. It looks like this low could be fairly slow to move out of the region, thanks in part to an area of high pressure to our east blocking it. We’ll see clouds along with scattered showers hanging around until Tuesday. Temperatures during this period will be cool due to the clouds and rain, with daytime highs expected to be in the 10 to 14 C range and overnight lows around 8 C.

Usual temperature range for this period: Highs: 12 to 22 C; lows, 1 to 10 C.

About the author

Co-operator contributor

Daniel Bezte

Daniel Bezte is a teacher by profession with a BA (Hon.) in geography, specializing in climatology, from the U of W. He operates a computerized weather station near Birds Hill Park.



Stories from our other publications