Lots of snow left to melt and run off

Forecasts are for more than the average amount of snow to run into Okanagan Lake this year, but more from the east than west side.

None of the forecasts suggest this year there will flooding in the Okanagan similar to last year, but it’s all dependent on the weather at this point, say forecasters from around the province.

Although inflow from snow melt to Okanagan Lake is expected to be slightly above normal, more of that will come from the Mission Creek watershed and less from the west side of the lake than usual.

David Campbell from the River Forecast Centre in Victoria said there’s a fair bit of “spatial variability” in snowpack depth, with well above normal and more than last year in the Mission Creek watershed, but less than average at the Brenda Mine snow course, which is a lower elevation snow pillow for automatic measuring of snowpack.

Overall in the Okanagan the snowpack is at seven per cent above normal, he said, similar to last year, except there were then record rains in June, which combined with late snow melt to cause some flooding in the Central Okanagan.

He said it’s expected there will be slightly above-average inflows to Okanagan Lake this year.

With a recent revision to what ‘normal’ is, based on recent data, he noted that in the Okanagan there’s been a trend of 17 per cent decline in the snowpack. However, he said some of that could be made up with more falling as rain rather than snow, because the melt is occurring earlier.

Low elevation snow measuring sites are showing more changes than high elevation ones, which fits in with Climate Change projections, he noted.

He warned it’s likely we will see the Spring freshet earlier in future so we will have to rely more on rainfall for summer water supplies.

Environment Canada forecaster Doug Lundquist pointed to a warming trend in the coming week that will consolidate the snowpack at upper elevations and begin the melt from there.

Although there will be ups and downs, overall, the outlook for the next two weeks is for above average temperatures, and a 50 per cent chance it will be drier than average.

That said, he said spring and fall are the dry seasons in the Okanagan, while mid-May to July is the monsoon season here.

Those June rains are needed to carry us through the dry summer, he added.

The long-range outlook for May is for drier than normal weather, but he said June is a really wet month in the interior.

 

jsteeves@kelownacapnews.com