On July 9th, Calgary and other nearby cities experienced a day of relatively calm winds. Residents of Calgary noted very calm conditions (low wind speed) at 7:00 pm, with westerly winds of 16 kmh. At around 8:00 pm, we had strong winds suddenly appearing from the NW of 46 kmh. The wind speed nearly tripled within an hours time! In Red Deer, this occurred at about 6:00 pm. Cloud rolls and other strange cloud formations were also witnessed (see middle photo).
What is interesting is that we also see (bottom right) a wave coming from the NW, which passes over the radar centre for the Calgary (Strathmore) radar site at the same time (8:00 pm).