Atmospheric River on its Way Saturday and Tuesday – Prepare for the worst, hope for the best!

As expected, Thursday’s rain was only about as bad as an average November rain. Port Alberni Airport received just under 50mm from 9AM Wednesday to 11PM Thursday. Alberniweather received 41mm in town. Nothing too serious.

What is of interest, however is the snowpack. Below is the webcam image from the new satellite-linked camera on Mt. Arrowsmith in the Cameron River/Cameron Lake/Little Qualicum drainage.

The latest picture is from Thursday morning. There is definitely some fresh snow on the trees and on the ground and it’ll be below freezing up there now. The bad news is the next two Atmospheric Rivers will likely warm up the freezing level and we’ll have rain on top of this snow. That’s going to make river levels higher along with the extreme rain that is coming.

What to expect from Saturday:

Rain will start Saturday morning in most areas. By 4PM, there should be about 20-25mm already in the rain gauge in Port Alberni and the Fraser Valley. 40-50mm in Tofino and 40-50mm in the North Shore highlands overlooking the Fraser River.

Then we get to the totals from 4PM Saturday to Sunday 4PM:

Unfortunately, this is looking like a worst case scenario repeat. Once again, Port Alberni is going to be on the edge of the “River”. Points south on Vancouver Island and in the Fraser Valley are going to get extremely high 24hr totals Saturday/Sunday.

Port Alberni/Courtenay/Parksville/Nanaimo: 20-25mm

Tofino/Cowichan Lake/Victoria (particularly western communities): 40-70mm

Fraser Valley, including the high elevations: 70-100mm or more.

There are even some yellow areas in the image above for the North Shore mountains suggesting over 200mm. Add up to the two images above and you get to totals similar to those of the original storm. The only bright spot is that the rain will again be short-lived compared to the big storm, but that is tempered by the fact there is likely going to be more snowmelt in this event. Rain should end by Sunday afternoon or Sunday night for the extreme Eastern part of the Fraser Valley.

Thankfully, we get a break on Monday. And there is some good news.

Looking ahead to Tuesday – A Glimmer of Hope.

The rain returns yet again with the 3rd atmospheric river in 6 days. Rain will begin again Tuesday morning. Below is the 24hr picture from 4AM Tuesday to 4AM Wednesday. Another bout of heavy rain on the West Coast with lighter amounts starting by Wednesday morning on southern Vancouver Island and the Fraser Valley.

Here’s the good news. The model has backed off on the atmospheric river coming down the coast. Instead it appears to expect it to be focused more on the North Island and Central Coast areas. Not good for them, but better for the Southern Coastal areas. Here is the 24hr accumulation Tuesday 4AM-Wednesday 4AM.

A much lighter load. Only another 40mm or so for most of the hard hit areas. Let’s hope this is the forecast that comes true.

Take care out there everyone and stay dry.

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