The June-July Precipitation Pattern in the Prairie Provinces of Canada

Few studies exist which deal with the synoptic climatological explanation of precipitation problems in the Canadian Prairies. Under particular consideration is the summer precipitation regime in the Prairie Provinces of Canada which is so significant for the cultivation of spring wheat. An attempt has been made to explain the June-July precipitation in the interior plains of Canada in terms of surface and upper atmospheric flow patterns. A unique feature of the precipitation pattern is that while in the southern half of this area, June is the month of maximum precipitation, in the northern half it is July. The investigation reveals that this interesting precipitation regime is related to the unusual extension of the Pacific High Pressure cell towards the northeast and a northward displacement of jet streams, frontal zones, and cyclonic tracks.