Snow packs in northern B.C. continue to run well above average, leading to concerns of floods this spring.
According to the April 1 report from the River Forecast Centre, snow packs in both the Upper Fraser and Nechako basins are the highest recorded on that date since records have been kept, a period of about 60 years. The Upper Fraser is at 152 per cent of normal, while the Nechako is even higher at 165 per cent.
The report says combined cooler and wetter weather in March across the province meant significant growth in all snow packs. In fact, all regions are now above normal, with the Okanagan-Kettle the lowest at 104 per cent of normal.
While the added snow in some basins has lessened the danger of drought this spring and summer, it has raised the risk of flooding in other areas.
“This year, snow packs are at levels of concern for increased flood risk in the Upper Fraser, Nechako, Columbia, Kootenay, Peace and Skeena-Nass basins,” the report says.
By April 1, about 95 per cent of the annual snow pack has normally accumulated. For most areas, the change from accumulation to melt starts in the middle of the month, making the April 1 survey key in assessing flood risk.
The report notes the weather over the next few months will be the determining factor in how much, if any, flooding occurs. The current long-range forecast is for cooler weather for the rest of April and into May, followed by warmer temperatures. While this may sound like a good scenario for avoiding floods in the region, the report cautions it could lead to more problems.
“(The forecast for cooler weather) has the potential to prolong the snow accumulation season and delay the onset of the snow melt season. … A rapid transition from cooler to hotter weather during the snow-melt season (May and June) is something to watch for because of its potential impact on flood generation.”