CW3E Event Summary: 18-20 October 2024
25 October 2024
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Strong Atmospheric River Produced Heavy Rain in Southeast Alaska and British Columbia
- An atmospheric river (AR) brought heavy precipitation to southwestern British Columbia and northwestern WA during 18–20 October.
The AR:
- The AR formed within a plume of subtropical moisture over the central North Pacific Ocean and made landfall in British Columbia on Fri 18 Oct.
- AR3–4 conditions (based on the Ralph et al. 2019 AR Scale) were observed in southern Vancouver Island and coastal WA.
Impacts:
- At least 5-10 inches of precipitation fell over much of southwestern British Columbia, the Olympic Peninsula, and the North Cascades.
- Heavy rain caused significant flooding on the Coquitlam River in Port Coquitlam, BC, with streamflow exceeding the previous record from March 2007.
- Minor riverine flooding also occurred in northwestern WA.
MIMIC-TPW2 Total Precipitable Water
Valid: 1200 UTC 17 October – 1200 UTC 21 October 2024
Click images to see loops of GFS IVT/IWV analyses Valid 1200 UTC 17 October – 1200 UTC 21 October 2024 |
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Summary provided by C. Castellano J. Kalansky; 25 Oct 2024
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