Water Supply Outlook for Alberta

October 2004

Water Year 2004 Precipitation (November 1, 2003 to September 30, 2004)

The water year encompasses precipitation which contributes to Alberta's active runoff season of March through September. This includes the previous winter's precipitation, which creates snow for spring melt, and precipitation through to the end of September, typically the last full month of open water flows. Most areas of Alberta recorded normal to above-normal precipitation this year with a few exceptions in Northern Alberta. The Peace River and Grande Prairie areas experienced much-above-normal precipitation whereas the northeastern portion of the province and High Level recorded below-normal to much-below-normal precipitation respectively (Figure 1). Normal to above-normal precipitation was recorded in southern Alberta with the exceptions of Empress which recorded much-above-normal precipitation and Del Bonita where below-normal precipitation was recorded (Figure 2). Highest precipitation totals for the year were recorded in the mountains and in the Swan Hills-Slave Lake area (Figure 3).

September 2004 Precipitation

Most areas of northern and central Alberta recorded above-normal to much-above-normal precipitation with the exceptions of High Level and Lloydminster where normal precipitation amounts were recorded (Figure 4). All of southern Alberta experienced below-normal to much-below-normal precipitation with the exceptions of the Rocky Mountain House and Cypress Hills where above-normal to much-above-normal precipitation was recorded (Figure 5). Highest precipitation totals for the month were recorded in the Swan Hills-Slave Lake area, where minor flooding occurred due to a storm early in the month (Figure 6).

Summmer Precipitation (May 1, 2004 to August 31, 2004)

Much of Alberta recorded summer precipitation ranging from near-normal to above-normal with the exceptions of the High Level, Fort Chipewyan and Fort McMurray areas which recored much-below-normal precipitation, and the Grande Prairie , Pincher Creek and Medicine Hat areas which recorded much-above-normal precipitation (Figure 7). In southern Alberta, areas south of Calgary recorded above-normal to much-above-normal precipitation. Areas north of Calgary recorded mostly normal precipitation except for Drumheller and Red Deer, which recorded above-normal to much-above-normal precipitation (Figure 8). Summer precipitation has been highest in southern mountain areas, the northern foothills, and the Slave Lake area (Figure 9).

Winter Precipitation (November 1, 2003 to April 30, 2004)

The entire province recorded below-normal to much-below-normal winter precipitation except Peace River and Cold Lake which recorded near-normal precipitation (Figure 10), and Empress which recorded above-normal precipitation (Figure 11). Winter precipitation totals are shown in Figure 12.

Soil moisture at the end of this period, May 1, 2004, was measured by Alberta Agriculture. Most of the province's soil moisture is below-average, with areas east of Calgary and Drumheller much-below-average. Average soil moisture conditions exist in the area between Peace River and Slave Lake, in a narrow band through Edmonton, and along the Saskatchewan border from the Lloydminster area north towards Fort McMurray. Soil moisture conditions are drier than last spring, but not as dry as in 2000 or 2001. A map of Alberta Agriculture's findings is available here.


Fall 2003 Precipitation (September 1 to October 31, 2003)

Generally, precipitation recorded in both northwestern and central Alberta varied from near-normal to much-below-normal, while much-above-normal precipitation was recorded in northeastern Alberta (Figure 13). In southern Alberta, precipitation totals generally ranged from near-normal to much-above-normal except at Pincher Creek, Lethbridge, Coronation, Drumheller and the Bighorn Dam where much-below-normal precipitation was recorded (Figure 14). Despite generally good precipitation totals (Figure 15) ,soil moisture conditions are very dry in most areas of the province, since late summer was generally very dry and much of the autumn precipitation fell as snow. The only area having average fall soil moisture is in east-central Alberta, along the Saskatchewan border. A map showing soil moisture conditions in the province is available from the Alberta Agriculture website through this link.

Long-Lead Precipitation Outlook

Environment Canada's long-lead precipitation forecast for Alberta issued on October 1, 2004 for the period October through December 2004 is for below normal precipitation, except for the western side and southeast corner of the province, where normal precipitation is forecast, and the Grande Prairie area, where above normal precipitation is forecast. The long-lead forecast for December through February is for below-normal winter precipitation, except in the northern third of the province, where normal to above-normal precipitation is forecast. 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) long-lead precipitation forecasts issued on September 16, 2004 for October though December 2004 is for an equal chance of normal, below-normal or above-normal precipitation for southern Alberta. El Nino conditions continue to develop, and as a result warm temperatures and below-normal precipitation are forecast for southern and central Alberta for December through February. NOAA's long-lead precipitation outlook is available from their website located at: http://www.cpc.ncep.noaa.gov/products/predictions/90day/.

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