A monster of an atmospheric river.

My view for the next ten days or so.

We are settling in for one of the biggest rainfall events in years. Today it started raining and the expectation is that a series of increasingly intense atmospheric rivers will be delivering rain to the west coast in increasing amounts over the next couple of weeks. In some places there will be 300-400 millimetres of rain falling, some of it as snow on the mountains. It won’t be very windy, which is a good thing.

The atmospheric beast responsible for this is a set of stable systems out in the Pacific, a low to the north the north and a high to the south of us that are generating a trough of moisture between them and extruding it right at us. By the time what Cliff Mass calls the Godzilla Atmospheric River arrives next week, the flow of moisture will be almost 5000 kms long, originating in a part of the Pacific Northwest of the Hawaiian Islands, near Midway. It’s amazing to look at the modelling.

This kind of pattern produces lots of flooding, so we’ll have to be on the look out for that. The land is saturated with water now, so everything will run off. Waterfalls will be spectacular, gullies and culverts will overflow, our reservoirs will be full, and probably a little murky with the tannins and suspended particulates. There may be landslides in some places. It’s gong to make for some very wet events here on Bowen Island, like Light Up The Cove on Saturday.