Lower Mainland residents can expect to get drenched if they go outside later today (March 14).

Environment Canada has issued an alert forecasting 50 to 80 millimetres of rain in Metro Vancouver through tonight.

The storm will also hit Howe Sound and the western Fraser Valley before it eases by Tuesday (March 15) morning.

The heaviest rain will occur near the mountains.

"Heavy downpours can cause flash floods and water pooling on roads," Environment Canada says. "Localized flooding in low-lying areas is possible."