Problem
It is a spring day in southern B.C., with temperatures of 12 ºC. Westerly winds push air off the ocean towards the coastal mountains, which are 1800m high. The dew point temperature of the air mass is 5oC. Determine what happens as the air is forced to rise by answering the questions below.
I. At what elevation does condensation begin on the western slope of the range?
II. What will the temperature of the air layer be as it passes over the summit of the range (i.e. at 1800 m)? You may wish to explain your steps.
III. What will the temperature of the air layer be after it has descended to the surface (i.e. at 0 m) over an interior plateau? Assume that all condensed moisture fell as rain on the windward slope (i.e. the descending air is now dry).
IV. Do you think it will be raining or snowing at the top of the Whistler-Blackcomb (at 1900 m elevation), the ski area north of Vancouver? Be sure to explain your steps.