Water Supply Outlook August 2010

Updated: August 18, 2010

Mountain runoff forecasts (natural volumes for March to September 2010)

Forecasts have slightly increased in Red Deer River and slighly decreased in North Saskatchewan River basins since July 1 forecast.

Oldman River basin

Bow River basin

Red Deer River basin

  • Below average to much below average for the Red Deer River at Red Deer and slightly much below average for Dickson Dam inflow March to September 2010 period
  • Below average to much below average for August to September
  • March - July recorded volumes below average to much below average for the Red Deer River at Red Deer and slightly much below average for Dickson Dam inflow.

North Saskatchewan River basin

  • Much below average for the Brazeau and Bighorn Reservoirs and below average to much below average for the North Saskatchewan River at Edmonton
  • Below average to much below average for August to September
  • March - July recorded volumes much below average for the Bighorn Reservoir and below average to much below average for the Brazeau Reservoir and the North Saskatchewan River at Edmonton

Precipitation can have a major impact on water supply between now and the end of September. The forecasts above assume that precipitation over the remainder of the winter period and through the summer will be normal. The range of possible precipitation scenarios is large however, and as a result, probable range forecasts and a minimal precipitation forecast of natural runoff volume are also provided for each individual basin. Since more information becomes known over time, forecast ranges will narrow over time. Streamflow volume forecasts are updated monthly from February to May, and again in July. Recorded 2010 volumes are preliminary and subject to change.

Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.

Mountain snowpack (issued in December to June next year)

Plains Spring Snowmelt Runoff Forecasts (issued in March and April each year)

Plains Snowpack (issued in March and April each year; Cypress Hills mid to late January and February)

Precipitation

Contoured maps of precipitation amounts and as a percent of normal for the past month and for current and recent seasons are available here. Maps of precipitation amounts for the most recent day, week and month to date are available here.

Soil Moisture

Alberta Agriculture models soil moisture for non-mountainous, agricultural areas of Alberta. Modelled soil moisture compared to average as of August 2, 2010 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on August 1, 2010): Temperature above normal for Southern half of Alberta for August-October 2010 and normal in the rest of the province. Precipitation below normal in Lethbridge region and above normal in Central Alberta. Normal precipitation for the rest of the province.

National Oceanic and Atmospheric Administration (NOAA) (issued on July 15, 2010): An even chance of below normal, normal, or above normal temperature and precipitation in southern Alberta, for August through October 2010.

Climate indicators : The NOAA reported on August 5, 2010 that La Nina conditions are expected to strengthen and last through the Northern Hemisphere winter 2010-11.

Note that forecasting weather for such a long time period into the future is very difficult, and so the historical accuracy has been variable, dependent on location and time period, and is often low, more so for precipitation than temperature. Environment Canada provides an assessment of their forecast method's historical accuracy on their website.

Reservoir storage

Water storage volumes in the major irrigation and hydroelectric reservoirs of the Milk, Oldman, Bow, Red Deer North Saskatchewan, and Athabasca River basins is updated each weekday and is available in the Provincial Reservoir Storage Summary.

Questions

Background information on the Water Supply Outlook is available in Frequently Asked Questions

Media Contact:
Communications Division, Alberta Environment
Phone: (780) 427-6267