check out the complexity of this pattern of clouds (chinook) ,the two main clouds stuck around till later that evening, long after dark, very odd.Wikipedia:In Canada[edit]Where Chinooks occur most frequently.Chinooks are most prevalent over southern Alberta in Canada, especially in a belt from Pincher Creek and Crowsnest Pass through Lethbridge, which get 30 to 35 Chinook days per year on average. Chinooks become less frequent further south in the United States, and are not as common north of Red Deer, but they can and do occur annually as far north as High Level in northwestern Alberta and Fort St. John in northeastern British Columbia, and as far south as Albuquerque, New Mexico.[citation needed]In southwestern Alberta, Chinook winds can gust in excess of hurricane force 120 km/h (75 mph). On November 19, 1962, an especially powerful Chinook in Lethbridge gusted to 171 km/h (106 mph).[citation needed]