Water Supply Outlook for Alberta

March 2003

February 2003 Precipitation

In northern and central Alberta, much of the western half received much-above-normal precipitation in February, except for the mountains which generally received much-below-normal precipitation, and the High Level area which received near-normal precipitation. Precipitation in the eastern half of northern and central Alberta ranges from much-below-normal in the Fort Chipewyan and Coronation regions to normal in the Edmonton and Cold Lake regions (Figure 1). In Southern Alberta, precipitation amounts generally range from above-normal to much-above-normal, except in southwestern areas where below-normal to normal precipitation was recorded (Figure 2). In mountain and foothill areas, near-normal precipitation amounts were recorded in two spots, southwest of Pincher Creek and southwest of Calgary. (Figure 3).

Winter Precipitation (November 1, 2002 to February 28, 2003)

Most of the province has received much-below-normal precipitation this winter, except for a broad band of normal precipitation extending from the Grande Praire-Peace River district through the Slave Lake, Edson, and Edmonton regions and into the Red Deer and Calgary areas (Figure 4). A band of normal to much-above-normal precipitation extends eastward from Calgary to the Empress area (Figure 5). Mountain areas have received much-below-normal precipitation this winter (Figure 6).

Fall Precipitation (September 1 to October 31, 2002)

Below-normal to much-below-normal precipitation was recorded north of Red Deer in the September and October 2002 period, except for the Fort Chipewyan and Peace regions where precipitation was much-above-normal (Figure 7). Areas south of Red Deer recorded above-normal to much-above-normal precipitation (Figure 8). The least precipitation recorded was in east-central Alberta (Figure 9).

Soil moisture going into winter is below-normal to much-below-normal north of Calgary. South of Calgary, soil moisture is generally normal to above-normal, especially west of Lethbridge and east of Medicine Hat. A map of fall soil moisture is available from Alberta Agriculture at:


Long-Lead Precipitation Outlook

Environment Canada's long-lead precipitation forecast issued on March 1, 2003 for the spring period (March through May) is for near-normal precipitation in the province, except the Peace River-Slave Lake-Edson area and areas along the border with the Northwest Territories, where above-normal precipitation is expected. The long-lead forecast for summer (June through August) is above-normal precipitation in the plains areas from Calgary to the Northwest Territories border, and normal precipitation elsewhere. Environment Canada's long-lead precipitation outlook is available from their website located at: http://weatheroffice.ec.gc.ca/saisons/index_e.html.

The National Oceanic and Atmospheric Administration (NOAA) is forecasting below-normal precipitation for the southern portion of the province during the spring period (March through May). NOAA's long-lead precipitation outlook is available from their website located at: http://www.cpc.ncep.noaa.gov/products/predictions/90day/.

NOAA indicates that the moderate El Nino affecting us this winter has been steadily weakening over the past two months and is expected to continue to weaken. The strength of this El Nino event was lesser in magnitude than the last major El Nino event, which occurred in the winter of 1997-98. The significance of an El Nino event to the province of Alberta is that winter precipitation is typically below-normal during such events.

For technical enquires about this web page please contact Alberta Environment - Environmental Management Water Management Operations Branch at AENV-WebWS@gov.ab.ca