Fraser Valley – A special weather statement from Environment Canada was put into effect Thursday afternoon for the Fraser Valley – east including Chilliwack and and Fraser Valley – west including Abbotsford.
Expect heavy rain over the South Coast this weekend. Completely the opposite of the past hot dry summer.
A major change in the weather pattern will develop on Friday. The high pressure system that has trapped wildfire smoke over Southern B.C. will finally shift east thanks to a pair of incoming storms. The storms will merge two jet streams into a single river of sub-tropical moisture that will bathe the South Coast with the first significant rainfall in months.
Weather models are indicating 80 to 120 mm of rain over the South Coast between Friday night and Monday morning. 20 to 30 mm of rain is expected to carry over into the mountainous regions of the interior during the same period.
Due to the drought conditions over these regions, the soil has a reduced capacity to absorb water. Heavy rainfall thus increases the risk of flash flooding. Additionally, given the recent prolonged dry period, road surfaces may become slippery resulting in poor driving conditions.
To mitigate the risk of flash flooding, make sure drain spouts and sewer covers are free of debris, so water can freely drain. During heavy rains, avoid roadway underpasses, drainage ditches, low lying areas and water collection areas. They can unexpectedly flood or overflow. Do not try to drive across a flooded road. You cannot tell the condition of the road under the water.
The public is advised to monitor future forecasts and warnings as warnings may be required or extended.
Please monitor the latest forecasts and warnings from Environment Canada at www.weather.gc.ca.