B.C.’s coast is set to get completely drenched once again, with some areas expecting to receive more than 120 millimetres of rain in less than 48 hours.
Localized flooding, flash floods, and pooling water on roads are all possible. We will also experience a noted rise in river and creek levels, which will lead to an increased risk for washouts.
Plus, with this type of weather, we tend to see a devastating loss to the mountain snow pack.
So why are we getting so much rain? It’s all thanks to an intense atmospheric river.
An atmospheric river (AR) is a long, narrow feature in the atmosphere that can transport copious amounts of tropical or subtropical moisture in the form of water vapour. As the name suggests, it’s sort of like a river in the sky.
It dumps all of that water vapour as heavy rain or snow for high elevation mountains.
This isn’t the first time the B.C. coast has experienced something like this.
The region can experience more than 20 atmospheric rivers in a single year. According to the NOAA, on average the west coast receives between 30 to 50 per cent of its annual precipitation from atmospheric river events.
Some of you may be wondering, “I thought this was a Pineapple Express?”
And you’re right. An atmospheric river is the same thing as a Pineapple Express.
Those of us on the west coast have been using the term Pineapple Express for many years; perhaps it makes us feel a little better about getting soaked. But the term atmospheric river can be applied globally.
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