Water Supply Outlook February 2018
Updated: February 7, 2018
Mountain runoff forecasts (natural volumes for March to September 2018)
Milk River basin- Above average for Milk River at Western Crossing Average for Milk River at Milk River and Milk River at Eastern Crossing
- Above average for Belly River, Oldman River near Brocket and Oldman River at Lethbridge
- Average for St. Mary River and Waterton River
- Above average for Bow River at Banff and Calgary, Lake Minnewanka and Spray River
- Average for Kananaskis River, Elbow River and Highwood River
- Above average for Red Deer River at Dickson Dam
- Average for Red Deer River at Red Deer
- Much above average for Bighorn Reservoir
- Above average for North Saskatchewan River at Edmonton
- Average for Brazeau Reservoir
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 August (dependent on flood events).
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, 2018:
- Oldman River basin: below normal to much above normal, ranging from 87% at Allison Pass to 146% at Lee Creek “Q” (7 sites surveyed; Akamina Pass snow pillow offline until 2019 season due to Waterton Fire).
- Bow River basin: generally above average, ranging from 96% at Lost Creek South to 136% at Little Elbow Summit (20 sites surveyed).
- Red Deer, North Saskatchewan, Athabasca River basins:
Red Deer River Basin: (0 sites surveyed)
- Upper Peace River basin in British Columbia: as indicated in British Columbia's Snowpack and Water Supply Outlook
North Saskatchewan River Basin: much above average, ranging from 116% at Southesk to 138% at Limestone Ridge (3 sites surveyed).
Athabasca River Basin: : average at Marmot-Jasper (104%) and above average at Sunwapta Falls (110%) (2 sites surveyed).
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. 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 snow water equivalent (SWE) as of February 5, 2018 is shown here.
- 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 and Forestry models soil moisture for non-mountainous, agricultural areas of Alberta. Modelled soil moisture compared to average as of January 31, 2018 is available here.
Long Lead Precipitation Outlooks
Environment Canada (issued on January 31, 2018): Temperatures is forecast to be below normal for the February through April 2018 period, except for the southern east slopes, which are forecast to be normal. Precipitation is forecast to be above normal for the February through April 2018 period, except for northeastern Alberta which is forecast to be normal.
National Oceanic and Atmospheric Administration (NOAA) (issued on January 18, 2018): Below normal temperature is forecast for southern Alberta for February through April 2018. Above normal precipitation is forecast for southern Alberta for February through April 2018..
Climate indicators: The NOAA reported on January 11, 2018 that La Niña is likely (~85-95%) through Northern Hemisphere winter, with a transition to ENSO-neutral expected during the 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 and Parks
Phone: (780) 427-8636
