See the weird jagged cloud shape here? That's the sign of a chinook, which is a type of warm wind particular to this area of North America.
From Wikipedia (since I am no longer at uni, I can use Wikipedia in my writing now):
Chinook is a Pacific Northwest Indian word meaning 'snow-eater', as a strong Chinook can make snow one foot deep almost vanish in one day. Chinook winds can gust in excess of hurricane force (120 km/h or 75 mph). During the winter, driving can be treacherous as the wind blows snow across roadways sometimes causing roads to vanish and snowdrifts to pile up higher than 1 meter. Empty semi trucks driving along Highway 3 and other routes in Southern Alberta have been known to be blown over by the high gusts of wind caused by chinooks. One of the most striking features of the chinook is the chinook arch, which is a band of stationary stratus clouds caused by air rippling over the mountains due to orographic lifting. To those unfamiliar with the chinook, the chinook arch may look like a threatening storm cloud at times. However, they rarely produce rain or snow. It is said that chinook winds can cause a sharp increase in the number of migraine headaches suffered by the locals and are often called "chinook headaches".
When we went hiking the other day, Seamus took a really cool video showing how windy it was (it was about 15 degrees but so windy we nearly got blown over) but I can't make it upload. This is because our wireless connection is affected by...the wind. And cloud, and snow, and sun...today is another chinook day (13 degrees) but it's due to drop to -8 over night and snow! Yay!