Water Supply Outlook January 2018

Updated: January 5, 2018

Mountain runoff forecasted natural volumes for March through September 2018

Milk River basin
  • above average

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. However, the range of possible precipitation scenarios is large, therefore probable range forecasts and potential minimum forecasts of natural runoff volumes are also provided. As 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 for updated information regarding runoff conditions.

Mountain snowpack

Snow accumulations measured in the mountains as of January 1, 2018

  • Oldman River basin: much above average, ranging from 126% at South Racehorse Creek to 156% at Many Glacier (2 sites surveyed – Akamina Pass survey site not surveyed this month; Akamina Pass snow pillow offline until 2019 season due to Waterton Fire).
  • Bow River basin: average to much above average, ranging from 93% at Mud Lake to 135% at Skoki Lodge (8 sites surveyed).
  • Red Deer basin: (0 sites surveyed)
  • North Saskatchewan basin: much above average, ranging from 134% at Southesk to 153% at Limestone Creek (2 sites surveyed).
  • Athabasca basin: (0 sites surveyed)
  • Upper Peace River basin in British Columbia: as indicated in British Columbia's Snowpack and Water Supply Outlook

It is early in the winter, and snow measurements are only conducted at about half the locations. A full data set will be available in February. 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-fifths of the seasonal total.

Plains snowpack

  • Information on plains area snowpack will be available in March as snow course measurements will be conducted near the beginning of the month.
  • Environment Canada map of satellite estimation of plains snow water equivalent (SWE) as of January 1, 2018 is shown here.
  • Alberta Agriculture publishes maps of modelled plains snow accumulations and accumulations as compared to normal.


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 December 31, 2017 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on December 31, 2017): Temperatures is forecast to be normal for the January through March 2018 period, except for southern Alberta, which is forecast to be below -normal. Precipitation is forecast to be normal for the January through March 2018 period, except northeastern and southwestern Alberta which are forecast to be above normal.

National Oceanic and Atmospheric Administration (NOAA) (issued on December 21, 2017): Below normal temperature is forecast for southern Alberta for January through March 2018. Above normal precipitation is forecast for southern Alberta for January through March 2018.

Climate indicators: The NOAA reported on December 14, 2017 that La Niña is likely (exceeding ~80%) through the Northern Hemisphere winter 2017-18, with a transition to ENSO-neutral most likely during the mid-to-late 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.


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