Water Supply Outlook February 2010
Updated: February 19, 2010
Mountain runoff forecasts (natural volumes for March to September 2010)
Milk River basin- Below average
- Below to much below average for the St. Mary and Belly Rivers
- Below average for Waterton River and Oldman River at Brocket and Lethbridge
- Below average to average for the Elbow River at Bragg Creek, Highwood River at the Mouth and Kananaskis River at Kananaskis
- Below average for the Cascade and Spray Reservoirs
- Below to much below average for the Bow River at Calgary
- Much below average for the Bow River at Banff
- Below average to average
- Below average for the Bighorn and Brazeau Reservoirs
- Below to much below average for 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. Streamflow volume forecasts are updated monthly from February to May, and again in July.
Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.
Mountain snowpack
Snow accumulations measured in the mountains as of February 1, 2010:
- Oldman River basin: ranging from below to much below average at seven locations. Much above average at two locations (Wilkinson in the upper Oldman River basin and Lee Creek in the middle St. Mary River basin. Average at Akamina.
- Bow River basin: highly variable in the Upper Bow River basin, but near average overall. Near average in the Kananskis area, slightly above average in the Elbow River basin, and below average to average in the Highwood River basin.
- Red Deer, North Saskatchewan, Athabasca River basins: above to much above average in the Athabasca and North Saskatchewan River basins, generally slightly above average in the Red Deer River basin.
- Upper Peace River basin in British Columbia: below normal, as indicated in British Columbia's Snowpack and Water Supply Outlook
Mountain snowpack is an important source of water supply to reservoirs in the spring. Accumulation at this time of year typically accounts for nearly two-thirds of the seasonal total.
Plains snowpack
- Snow course measurements were taken in mid-January in the Cypress Hills, and values were above to much above average, highest or second highest in about 30 years of record at 3 of 5 locations. Detailed information on plains area snowpack will be available in March as snow course measurements will be conducted near the start of the month.
- Environment Canada map of satellite estimation of plains percent of normal snow water equivalent (SWE) as of February 1, 2010 is shown here. Although southern plains snowpack is indicated as over 200% of normal, snow water content amounts are generally only moderate or moderately high as typically there is little snow in this area.
- Alberta Agriculture publishes maps of modelled plains snow accumulations and accumulations as compared to normal.
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 February 7, 2010 is available here.
Long Lead Precipitation Outlooks
Environment Canada (issued on February 1, 2010): above normal temperature in the western half of Alberta and normal temperature for the rest of the province and below normal precipitation for Alberta, except normal precipitation for the Cold Lake area, for the February through April 2010 period.
National Oceanic and Atmospheric Administration (NOAA) (issued on January 21, 2010): Above normal temperatures and an even chance of below normal, normal or above normal precipitation in southern Alberta, for February through April 2010.
Climate indicators: The NOAA reported on February 15, 2010 that significant El Nino conditions are likely to continue into spring 2010, gradually transition to ENSO-neutral conditions during Northern Hemisphere spring.
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
