Snowpack sends mixed signals

The latest data from the BC River Forecast Centre is a mixed blessing for growers concerned about a dry start to the season.

The province’s April 1 snow and water supply bulletin indicates that the provincial snow pack decreased to slightly below normal for April 1 to 88% versus 94% a month earlier. The snow index for the Fraser River basin at Hope was normal at 100%.

However, a glance at the snow water equivalent for April 1 indicates that the water supply is 82% of normal in the Lower Fraser. While the Okanagan and Boundary regions are in the best position, with their snowpacks at 113% and 120% of normal, respectively, a lack of precipitation in March concerns analysts.

“March was very dry throughout BC,” the River Forecast Centre reports. “Only a few climate stations in coastal locations measured above 50% of normal precipitation for the month. Several stations ranked among the five lowest March precipitation totals in recorded history. These include Abbotsford, Penticton, Vernon, Quesnel [and] Kamloops.”

Nevertheless, precipitation since the start of the year means that snow water equivalents in many regions – including both the Lower Mainland and Okanagan – showed improvement over January.

According to the Canada Drought Monitor, most areas of BC affected by drought as of February 28 would be out of drought by the end of March. However, large swathes of the Peace, the Squamish-Lillooet region and northern Vancouver Island were set to see drought conditions worsen.

The province will resume its own drought assessment later this spring.

The latest water supply bulletin attributes improving drought conditions to the La Niña weather pattern, which typically delivers late-season precipitation but also increases spring freshet risks. The bulletin calls out the Nicola River as being at an elevated risk of flooding this spring, though much will depend on weather conditions over the next three months.

On April 13, Emergency Management BC will address concerns regarding the spring freshet and the outlook for the 2023 wildfire season.