Slow snow melt in the Cariboo means the weather will determine if there’s flooding

A Hydrologist with the BC River Forecast Centre says the snowpack in the Chilcotin is at 241 percent of normal.

However, Jonathan Boyd says that number is a little bit misleading because that region has mostly lower elevations and the snow melt is two to three weeks behind schedule.

Boyd says snowpack is just one aspect of the potential for flooding.

“Another way we do statistical analysis on the snowpack is just by percentiles.  The way percentiles work is the 50 percent is the median and then say 100 percent would be an all-time record, and for the Chilcotin area it was around 84 percentile on average for the two stations, so it was above normal but not necessarily an extreme record.”

Boyd says it wasn’t the snowpack itself increasing in the Chilcotin, it’s just that the melt is a little bit delayed.

“When you did into the data it averages about 16 centimetres of snow, that’s what the average measurement was for April 1st, and in a typical year that might be like 7 centimetres, so when we get into percent of normal when the snowpack is really low we can end up skewing the data significantly.”

Boyd says the Quesnel River is lower than what it was last month.

“For April 1st Quesnel is at 103 percent of normal and that was a drop from 111 percent for March 1st. The Quesnel region, the average percentile there was the 63rd percentile. One of the lowest elevation sites in the Quesnel area, Granite Mountain, which has an elevation of 1.150 meters, it actually measured a record high.”

Boyd says as always, it is the weather that will ultimately decide if there is flooding or not in the region.

“The lower elevation watersheds are going to be at most risk if we get the heat toward late April or early May.  If we don’t get the warm weather, which is what happened last year when we didn’t really start to get any relatively warm weather until late May/early June, there likely won’t be a lot of flooding.   But if we get warm weather melting the snow quickly and then we get heavy rainfall on top of that melting snow, that’s where it can trigger some flash flood events especially in maybe smaller river systems, not necessarily as dramatic in the Quesnel River which is coming out of Quesnel Lake, but maybe some of the smaller tributaries of the Quesnel.”

Overall, Boyd says he feels the risk of flooding this year is lower than last year, although he says the potential is still there.