Just found this on the Environment Canada Website....
City of Calgary
3:01 PM MDT Wednesday 23 May 2007
Snowfall warning for
City of Calgary issued
Snowfall accumulations in excess of 10 centimetres are forecast for tonight and early Thursday.
An intense upper disturbance is tracking slowly southward across western Alberta. Widespread precipitation is forecast for much of the southern half of the province as the storm passes. In advance of the system, temperatures will fall to near or below freezing values especially over higher elevations in the southwest. Snow will begin this evening and spread southward overnight across the regions listed above. General accumulations of 10 to 15 centimetres are likely before the snow either begins to let up or changes to rain near midday Thursday. Higher amounts can be expected in mountain passes.