CALGARY -- It’s a restless forecast for the weekend.
The (literal) bright side is that it’s triggered by sun and heat. The less bright side, is that there’s plenty of instability to help thunderstorms along, which could mean more hail.
Again? How now?
One consistent element, and then a few smaller pieces. Today’s activity would spawn from northeasterly wind pooling moisture along the foothills. As we talked about in yesterday’s post, this activity is spurned along by the slow-moving low pressure area that’s been stuck like glue through Saskatchewan and Manitoba. It exists aloft, and near the surface, and is pushing air along. It’s really established now, to the point where isolated lightning strikes were firing off through the 4, 5, and 6 o’clock hours just west of Calgary. Low-pressure areas have a force at play called surface convergence. They pull air in, which means they could very well pull that unstable, moist airmass off the foothills and over Calgary. The combination of vertical motion and storm energy could generate nickel-sized hail in some areas.
Then, per that surface convergence element in the last paragraph, we can account a “ditto” for tomorrow and Sunday. The only change is that these storms will be pulled straight off the foothills, likely materializing as isolated thundershowers again for us.
Also, enjoy tomorrow as well as one can! We’re back into the summer solstice, also known as the longest day of the year. That’s because our planet reaches the maxima of its solar angle from rotation along its axis, or 23.5° - the earth is leaning our northern hemisphere as much toward the sun as it gets, which, in turn, makes for the earliest sunrise and latest sunset we get, for a total daylight amount of 16 hours, 33 minutes and 16 seconds. For comparison’s sake, on our winter solstice (December 21st), our day will be 8 hours, 39 minutes shorter.
Here’s the forecast:
Today:
- Mainly cloudy, afternoon storms possible
- Daytime high: 20°
- Wind: NW 15 km/h
- Tonight: evening thundershower potential, low 10°
Tomorrow:
- Sun-cloud mix, scattered showers and a chance for afternoon thunderstorms
- Daytime high: 23°
- Evening: chance of showers, low 12°
Sunday:
- Father’s Day – some sun, but scattered showers, afternoon thundershower risk
- Daytime high: 19°
- Evening: showers, low 10°
Monday:
- Mainly sunny
- Daytime high: 21°
- Evening: mainly clear, low 13°
Tuesday:
- Sun-cloud mix
- Daytime high: 26°
- Evening: some cloud, chance of showers, low 11°
Photo of the day sent by Shelley of yesterday’s sunset, looking west toward WinSport's Canada Olympic Park. You can submit your weather photos here!
