Monday, 15 October 2012

Chinook and a surprise

We stopped one cold night at Oldman River Dam recreation area in the grasslands of Alberta.
Stephen observed sadly that it wasn't as attractive as the Rockies. 
We had mountains in the distance on one side of us with the dam and water on the other. 
Not so bad!
The weather was suddenly much warmer but rather windy. A colourful sunset followed all around us.

All in pink!

Then in the morning!

Out there in night wear! It was worth getting up early.

I have found out that a Chinook caused this temperature change and subsequent impressive sunset and sunrise.

A Chinook is a foehn wind which is a type of dry down-slope wind that occurs in the downwind side of a mountain range.
A strong Chinook can make snow one foot deep almost vanish in one day. The snow partly melts and partly evaporates in the dry wind. Chinook winds have been observed to raise winter temperature often from below -20°C  to as high as 10-20°C  for a few hours or days, then temperatures plummet to their base levels.
The winds can be so strong as to derail trains. I'm glad we didn't experience a strong wind like that.

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