There hasn’t been much concern about spring flooding for most of British Columbia, but that attitude is slowly changing given the latest snowpack numbers.

Typically the provincial snowpack has peaked by mid-April, but this year it grew from 99% of normal to 113% of normal during the year’s fourth month.

The BC River Forecast Centre (BCRFC), which released the province’s May 1 snowpack numbers today, says that is certainly cause for concern.

“Flood risk has increased considerably due to colder April temperatures across the province and delayed snowmelt,” a BCRFC release explained. 

“Continued cool weather in May is increasing the risk for major flooding if a prolonged heat wave occurs later in the month or (in) June.”

Photo Credit: BC River Forecast Centre

The lowest snowpack in the province is still the Okanagan, but that also increased from 74% to 83% of normal over the last month.

On the contrary, the Liard snowpack in northern BC is an astonishing 413% of normal, despite being just 112% of normal when the numbers came out on April 1.

The remainder of BC’s snowpacks are between 100% and 145% of normal, even on Vancouver Island where that number was 74% in April and tied with the Okanagan for lowest in the province.

The suddenly higher-than-normal numbers leave much of the province in a delicate spot, but as always, weather over the remainder of the spring will be the biggest factor as to whether there is flooding.

“The major risks over the following two months are an extreme heat event or widespread heavy rainfall events,” noted the BCRFC. “A combination of intense heat directly followed by heavy rain is a worst-case scenario.”

But there are other factors, including the 2021 wildfire season and the November floods, both of which left certain watersheds more vulnerable to spring runoff.

Photo Credit: Natasha RoseFlooding hampered the Central Okanagan for weeks in 2017.

The BCRFC has drawn comparisons between this year’s snowpack and weather to similar conditions that caused problems in the distant past.

“The most likely cause for major flooding would be a period of persistent cool temperatures and wet weather into the late spring, followed by a sudden heat wave lasting at least five days,” the BCRFC said. 

“There is evidence that the 1948 and 1894 floods on the Fraser River were caused by this scenario…There are many similarities between the 2022 cool spring weather and the conditions preceding flooding in 1948.”

Forecasts continue to predict seasonal to below-seasonal temperatures through the province, which will likely delay the initiation of significant snowmelt into mid- or late-May.

The hope now is that the cooler weather isn’t followed up by a lengthy heat wave later this month or in June.

To see the BCRFC’s full May 1 snowpack report, click this link. The May 15 report will be released on May 20.