Environment Canada issued the warning early this morning. It states:
“A long episode of rain, at times heavy, is expected.
A strong Pacific front being fueled with energy and moisture from the subtropics will spread heavy rain to the inner south coast this evening.
The front will stall tonight and Wednesday resulting in a prolonged period heavy rain.
In Metro Vancouver and the Fraser Valley the highest rainfall will be be near the mountains with 100 mm expected by Thursday morning.
Squamish will also have rainfall of 100 mm by Thursday morning.
The heavy rain will taper off on Thursday morning as the front finally moves eastward out of the area.
If visibility is reduced while driving, turn on your lights and maintain a safe following distance. Localized flooding in low-lying areas is possible.
Rainfall warnings are issued when significant rainfall is expected.