Interesting Chinook yesterday that never quite got across the whole of Calgary..as i left work the temp where i was was hovering around 0c..i drove east along Stoney Trail (Calgary ring road) as i hit the north east loop the temp suddenly dropped to -18c within a space of about 1 mile... as i swung back west again it rose back to 0c again within the space of 1 mile..as i reached home it was -1c that was at 6pm..when i put the bins out at 7pm (in my tshirt) it was brutally cold..checked the temp and it was -19c at my house..so looked on the computer at the temp profile across Southern Alberta and there was a distinct line that cut the city in two between much warmer temperatures to the west and much colder air to the east..quite something to witness.