2017 Fraser River Freshet Information
Link to Provincial Forecasts: http://bcrfc.env.gov.bc.ca/bulletins/freshet.htm
Snow basin indices for March 1, 2017 range from a low of 45% of normal in the Liard to a high of 99% in the East Kootenay. The March basin index for the entire Fraser River basin is at 83%, which is approximately a 1-in-15 year low snowpack or the 10th lowest March index in the past 65 years.
This season’s snowpack can be considered “upside-down”, with higher than normal snowfall occurring at low elevations, but below-normal snow at high elevations. This is a result of colder than normal temperatures which have resulted in several low elevation precipitation events occurring as snow rather than rain. However, seasonally dry conditions have resulted in lower than normal snowpack at high elevations despite the colder conditions. Increased snow at low elevations plays a limited role in seasonal flood risk or water supply into the spring and summer.
Seasonal volume runoff forecasts are near normal for most basins across the province. By early March, 80% of the annual BC snowpack has typically accumulated. At this stage in the season there is limited indication that any region of the province is developing increased seasonal flood risk due to high snowpack. While snowpack is an important factor in seasonal flooding, weather during the melt season, particularly extreme rainfall events, can also create flood risk even in years with low snowpack.
With six to eight weeks remaining in the snow accumulation season, changes to the seasonal runoff outlook are possible, but at this stage would require extremely wet or cool conditions to make a significant impact on seasonal flood risk.
We will continue to monitor snowpack conditions and will provide an updated seasonal flood risk forecast in the April 1st 2017 bulletin, which is scheduled for release on April 6th