With rainstorms approaching and weeks of low-elevation snow destined to melt with the rain and warmer temperatures, experts in British Columbia say the south coast is facing a new flooding risk this week.
The River Forecast Centre, a provincial agency that monitors waterways, issued a high streamflow advisory Sunday afternoon for creeks and rivers on Vancouver Island and the Lower Mainland including Metro Vancouver and the Fraser Valley
Rivers are expected to begin rising Tuesday and peak Wednesday or Thursday, resulting in minor to significant flooding due to a mixture of heavy rainfall and significant warming in temperature.
Jonathan Bau, a meteorologist with Environment Canada, says the low-pressure weather system will bring in even warmer air than when the province was hit with atmospheric river flooding in November.
“It’s too early to call the storm an atmospheric river. Rainstorms are typical this time of year. However, because of the previous flooding that compromised B.C. infrastructures, such as bridges and homes, what would have been a normal storm is now a problem.”
“Areas that experienced flooding last year may have added vulnerabilities due to erosion and higher baseflow conditions,” warns the River Centre advisory.
Although the flooding could potentially be significant, the forecasting centre defines a high streamflow advisory as one in which “no major flooding is expected.”
The public is being advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the high streamflow period.
The incoming storm system is several days away and the exact location and intensity of the heaviest rainfall is still uncertain.
The B.C. Ministry of Transportation and Infrastructure announced Sunday night that Highway 1 in the Fraser Canyon will be closed on Monday morning at 8 a.m. due to an avalanche risk caused by the recent warm weather, as well as the incoming storm system.
