A special weather alert from Environment Canada is in effect for much of the south-central Interior, including the Revelstoke area.
Rain, with embedded thunderstorms, are expect on Thursday over the Southern Interior and combined with spring snow melt it could lead to rising river levels which may increase the risk of flooding.
“Given the fact rivers are already flowing quite high, any additional rainfall will create the potential of flooding,” said Matt MacDonald, meteorologist. “Tomorrow we will see a big change in the weather pattern, a return somewhat to last weeks showers.”
MacDonald said some areas could receive anywhere from 15 to 25 mm of rainfall. Last Friday Penticton received almost half of its average rainfall for the month of May in one day. Flooding was more rampant in the central and north Okanagan with some of the higher elevations in Kelowna receiving up to 40 mm of rain in that same period said MacDonald.
The River Forecast Centre issued a high-stream flow advisory for region and they are expecting potentially similar types of issues that communities faced last week after the heavy rainfall.
Quickly flowing water and the adjacent riverbanks are potentially unsafe. The weather statement warns to not approach washouts near rivers, creeks and culverts and to keep away from creek and river banks.
“This current weather pattern is very similar to the one last week that resulted in significant flooding throughout the region. Similar conditions, or potentially more severe conditions, are possible later this week and weekend,” states the advisory. “Rivers are expected to start rising in response to rain late-Thursday, with high flows on Friday and into Saturday, or later in rivers with longer response times.
According to Environment Canada, a developing cold front will stall over the Southern Interior and begin to transition out of the area on Friday. However, they are warning those living in vulnerable areas to be on alert.
The warning comes a few days after a weekend in which much of the Okanagan and Shuswap battled flooding.
“They should be prepared and realize that the heavy conditions we had last weekend might not end just yet. The rivers are very dynamic and there is really saturated soils out there. As well the riverbanks are loosened and unstable, so using caution is really important,” said Dave Campbell from the River Forescast Centre.
So far, the Revelstoke area hasn’t experienced any flooding. According to Environment Canada, Illecillewaet River flows peaked at about 215 cubic metres per second on May 7. In comparison, last year, when flows hit their peak in June, they reached well over 300 cubic-metres per second.
BC Hydro expects runoff in the Columbia Basin to be between 105 and 133 per cent of average. The Arrow Lakes Reservoir is expected to fill to within 1.5 metres of full pool by mid July. Summer levels are expected to be significantly higher than last year.
The River Forecast Centre issues streamflow advisories and warnings when necessary to provide alerts to potential flood conditions in the stream systems of the province. Please refer to the River Forecast Centre website for updated streamflow advisories or warnings.