Water Supply Outlook for Alberta

July 2002

February to June 2002 Precipitation

Monthly precipitation totals for select locations in the province reveal the two extremes in precipitation observed in the province since February 1 (Table 1). Monthly precipitation totals for various periods were ranked from highest to lowest for the period of record since 1912 (where available).

The May-June period produced the most records, as Carway, Lethbridge and Medicine Hat were the wettest on record, while Edmonton was the driest on record. The two extremes in precipitation are evident when looking at a longer period of record (February to June), as southern stations indicate near record high precipitation while northern and central regions show near record low precipitation.


June 2002 Precipitation

Areas north of Calgary remain very dry as very little precipitation was recorded in the month of June (Figure 1). A major storm event brought significant precipitation to southern Alberta in early June and as a result, precipitation was much-above-normal south of Calgary (Figure 2). The hardest hit areas were the Waterton Park and Milk River areas, which received in excess of 300 mm during the month of June (Figure 3).

Summer Precipitation (May 1 to June 30, 2002)

Summer precipitation (May 1 to June 30, 2002) reflects a similar pattern to that of June, as areas north of Calgary have recorded much-below-normal precipitation so far this summer (Figure 4). Areas south of Calgary have received much-above-normal precipitation this summer (Figure 5), with the Pincher Creek/Waterton area receiving in excess of 600 mm of precipitation (Figure 6).

Winter Precipitation (November 1, 2001 to April 30, 2002)

Winter precipitation (November 1, 2001 to April 30, 2002) is near normal in most areas west of a Grande-Prairie-Whitecourt-Red Deer-Lethbridge line and below-normal in areas east of this line (Figure 7). Precipitation in April helped raise winter totals closer to normal values, particularly in southern Alberta (Figure 8). Areas along the eastern side of the province have received much-below-normal precipitation to date and the higher elevations in the mountains, which have recorded above-normal values (Figure 9).

Fall Precipitation (September 1 to October 31, 2001)

Fall Precipitation was below-normal to much-below-normal in most areas of the province (Figure 10) with southern areas recording much-below-normal values (Figure 11). As a result of the low precipitation totals (Figure 12), soil moisture conditions remain very dry in most areas of the province. A map showing soil moisture conditions in the province is available from the Alberta Agriculture website located at:

Long-Lead Precipitation Outlook

Environment Canada's long-lead precipitation forecast on June 1 for the June to August period indicates above-normal precipitation in the northern half of the province and below-normal precipitation in southern Alberta. The forecast for the fall period (September to November) is for above-normal precipitation in the northern two-thirds of the province and normal in the southern portion of Alberta. Environment Canada's long-lead precipitation outlook is available from their website located at:

The National Oceanic and Atmospheric Administration (NOAA) is forecasting below-normal precipitation for the southern portion of the province during the summer (July through August) period. NOAA is forecasting for an equal chance of below-normal, normal or above-normal precipitation in the fall of 2002 (September to November). NOAA's long-lead precipitation outlook is available from their website located at:

NOAA indicates that a weak El Nino continues to develop 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