Water Supply Outlook for Alberta

December 2002

November 2002 Precipitation (Revised December 18, 2002)

Alberta recorded much-below-normal precipitation in November (Figure 1), with a band of below-normal precipitation recorded from Calgary to Lethbridge to Medicine Hat (Figure 2). The majority of the province recorded less than 20mm of precipitation for the month of November with the exception of the mountain areas (Figure 3).

Fall Precipitation (September 1 to October 31, 2002)

Below-normal to much-below-normal precipitation fell throughout much of Alberta this past fall (September and October 2002) (Figure 4). In southern Alberta, areas north of Calgary recorded generally above-normal precipitation. South of Calgary, fall precipitation was much-above-normal (Figure 5). Much-above-normal precipitation also fell in the Grande Prairie, Town of Peace River and Fort Chipewyan areas (Figure 6).

Soil moisture going into the winter freeze-up is below-normal to much-below-normal in most areas of the province. Exceptions are the southwest corner bounded by Calgary and Lethbridge, an area east of Medicine Hat, and a small area south of Valleyview, which are normal to above-normal. A map of fall soil moisture is available from Alberta Agriculture at: http://www.agric.gov.ab.ca/app21/rtw/selsubj.jsp


Long-Lead Precipitation Outlook

Environment Canada's long-lead precipitation forecast on December 1 for the winter period (December through February) is for below-normal precipitation in the southern two-thirds of the province and normal in the northern portion of Alberta. The long-lead forecast for spring (March through May) is above-normal precipitation in the northeastern quarter of Alberta, 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 winter (December through February) period. The long-lead forecast for spring (March through May) is normal precipitation for southern Alberta. 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 a moderate El Nino has developed in the tropical Pacific. Current indications are that the strength of this El Nino event will be less in magnitude than the event that 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. The last major El Nino event occurred in the winter of 1997-98.

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