The forecast of an intense series of subtropical storms aimed at B.C.’s South Coast has led Environment Canada to issue an extended rainfall warning for the Metro Vancouver region. The storm parade is expected to last for three or four days, until Thursday morning, and is influenced by the jet stream gathering warm moist air from the subtropical southern latitudes.
The mountains of Vancouver Island and the Lower Mainland’s North Shore will be bombarded with up to 100 mm of rainfall by Tuesday morning. Within Vancouver, lesser but still significant accumulations can be expected in addition to periods of strong and gusty winds.
However, that is only the expected accumulation from the first two storms, which far exceeds the rainfall warning criteria for a 24-hour period. Consecutive incoming storm systems will likely prompt the extension of rainfall warnings through much of the week.
The inflooding warm air will drive the freezing level to nearly 2500 metres. In some areas, additional water from snow-melt will add more water to drainage basins, creeks, rivers and already saturated soil, which could lead to localized flash flooding and water pooling on roads.
Feature Image: Rain clouds via Shutterstock