Snowpack levels in the Okanagan-Similkameen are at record lows this year as a result of higher than usual temperatures and reduced precipitation.
The snow basin index for the Okanagan is only 57 per cent of normal and for the Similkameen it’s only 37 per cent, according to the May 1 snow survey and water supply bulletin released last week by the B.C. River Forecast Centre.
Both these figures are the lowest ever for the period from 1985 to 2015 and both are below the provincial average, which is 69 per cent of normal as of May 1.
On May 1, the Osoyoos Times found almost no snow on the road up Mount Kobau and only small patches at elevations above 1,800 metres. Only on shaded areas of the north slope near Testalinden Lake was substantial snow observed.
The snowpack in the Okanagan is considered below normal as it falls within the 50 to 80 per cent range. This indicates a lower than normal seasonal flood risk, although a combination of extreme precipitation or combined hot and wet weather could still cause flooding, the report said.
The snowpack in the Similkameen is considered “extremely low,” suggesting that low flows can be expected this summer unless significant rainfall occurs through the spring and summer.
While the level of Osoyoos Lake is still within the target range, at 911.39 feet above sea level on Monday, the flow of the Similkameen River at Nighthawk is well below normal levels, according to readings from the U.S. Geological Survey.
On Monday, discharge of the Similkameen was measured at 4,700 cubic feet per second. This compares to a high of 17,900 on that date in 2013 and an average of 6,630 based on 86 years of records.
The snow survey and water bulletin notes that temperatures throughout B.C. were above average through April and conditions were also drier in the southern interior.
Environment Canada is forecasting a very high likelihood of above normal temperatures across B.C. in the period of May to July.
RICHARD McGUIRE
Osoyoos Times
