23-05-2025
Today's high of 18 C will be the coldest high for at least a week
An incoming blocking pattern in the upper levels, known as an Omega block, will produce at least a week of stable weather conditions, including elevated temperatures and little to no precipitation across the west.
This is the same type of synoptic setup that occurred with the record-setting Heat Dome in 2021 where two anchoring low pressure systems sit on the southernmost sides of a dominant ridge of high pressure.
The placement of and opposing circulations around the high and lows inhibit normal flow within the polar jet stream and trap warm air near the surface for a prolonged period of time.
Today's high of 18 C will be the coldest high for at least a week
On Friday, there is a chance of light and scattered rain or possibly some non-severe thunderstorm development across central and southern Alberta before that ridge settles over the west and extends into the territories.
Wind will also intensify throughout the day Friday with sustained winds in Calgary expected to sit around 20 km/h by the afternoon with gusts closer to 40 km/h.
Once that blocking pattern establishes on Saturday, daily highs in Calgary will range from 21 C to 28 C until early June, with overnight lows often in the double digits.
During that time there will be very little cloud cover, minimal wind and only a slight chance of rain (on Monday).
Today's high of 18 C will be the coldest high for at least a week
The average range of temperatures this time of year is 17 C for a high and 4 C for a low.
As this is such a large ridge that will extend east into Manitoba, it is expected to hinder efforts to contain wildfires in that province as hot, dry weather returns to that region.
