Mild weather for the Calgary Stampede parade, thunderstorms possible Friday night

After another night of active weather in southern Alberta, things have cleared for the Calgary Stampede parade.

Daytime conditions are expected to remain mild in Calgary on Friday, but once again - a shortwave trough has the potential to aid in the development of showers and thunderstorms later in the evening.

If thunderstorms develop Friday night the greatest threats include small to medium-sized hail, localized heavy rain, and stronger winds.

After Friday, the driving influence for weather in central and southern Alberta will be a dominant ridge of high pressure that originates in the southwestern United States and extends north to the western Territories.

Rather than follow the typical flow in the upper patterns where high and low pressure systems circle the globe along various jets, this ridge is expected to stall out due to a blocking pattern with anchoring low pressure systems holding that high in place.

Widespread heat warnings are likely by the end of the weekend as daytime highs in portions of British Columbia are expected to reach maximums near 40 C, and peak in the mid-to-high thirties in Alberta by the middle of next week.

Calgary’s daytime highs will range from 27 C to 34 C from Sunday to Thursday, with respective overnight lows of 14 C to 17 C.

Heat warnings are issued by Environment and Climate Change Canada for most of Alberta (excluding Pincher Creek, Cardston, Lethbridge and Medicine Hat) when daytime highs reach at least 29 C with lows of at least 14 C for at least two consecutive days.