Plains Runoff Outlook

As of March 1, 2005, spring snowmelt runoff is forecast to range from below average to average for most of Alberta's plains areas, with the exceptions of the Grande Prairie - Peace River - Whitecourt area where average to above average runoff is expected due to very wet or ice covered soil conditions, and the Rocky Mountain House region where soils are wet and the snowpack is above to much above average. The snowpack in the High Level and Fort Chipewyan areas is above to much above average, and so above average runoff is possible despite dry soil conditions if melt occurs quickly. There is also an area west of Cold Lake, between Lac LaBiche and the North Saskatchewan River to the south, where below to much below average runoff is expected due to dry soil conditions and much below average snowpack (Figure 1).

Significant melt has occurred in many plains areas during the first ten days of March, after snow measurements were taken. Abnormally high temperatures for this time of year prompted the River Forecast Centre to issue a Spring Runoff Advisory for the western half of central and north central Alberta, as far north as the Peace River area, where heavy snowpack and/or wet soil moisture conditions exist.

Routine snow surveys to monitor snowpack on the plains will be repeated at the end of March. Since it is still early in the typical runoff season, further weather conditions leading up to spring could change this forecast considerably. These forecasts assume a typical spring melt occurs; a late spring or abnormally high temperatures as experienced lately could result in runoff at the high end of the ranges provided, or possibly higher, depending on how quickly the snow melts. Check the Forecaster's Comments on the department website throughout the month for the most current conditions.