Incessant heavy rain will pile into the Pacific Northwest, USA 🇺🇸 & British Columbia, Canada 🇨🇦 in the next 72 hours due to a significant atmospheric river event.
Flooding & landslides are highly likely. The atmospheric warmth & moisture can be traced all the way to the tropics.
A strong meander in the jet stream allows Alaska to cool under Arctic air but also helps lift Tropical warmth & moisture into British Columbia & the Pacific Northwest.
Notice how the atmospheric moisture aligns and focuses on the same area. This is like nature's firehose. Extreme rain and locally very high freezing levels expected. Meteorologists call this an atmospheric river.
Some refer to this atmospheric river as 'the Pineapple Express'.
A warmer atmosphere can hold more moisture. As the tropical air crashes into the terrain of North America, air is forced upwards and enhances rainfall amounts further.
This is called orographic lift.
Speaking of temperature...
The thermal contrast between Alaska and California is extremely impressive for November.
More about that in this previous thread...
Public weather alerts & warnings for British Columbia can be tracked here: weather.gc.ca/warnings/index…
Pacific Northwest of the USA public warnings can be accessed here: weather.gov
#bcstorm #wawx #orwx
This thread and all the animations summarised on Instagram in a single post ⬇️
instagram.com/p/CWOgFHfsBFh/…
A month's worth of rain in 48 hours is possible. Not surprising in this setup to be honest, the source of air is very rich in moisture.
Certainly a significant atmospheric river (AR).
The freezing levels will also shoot to very high levels for a time (melting snow and adding to flood threat).
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