Intensified Flood Risks from Continuous Atmospheric Rivers in Northwest
The Pacific Northwest is enduring an escalated weather crisis with back-to-back atmospheric rivers, resulting in over 9 inches of rain and heightened flood dangers. This has led to road closures in Washington and disrupted Amtrak services between Seattle and Portland.
Flood watches are in effect until Wednesday evening across Washington and Oregon, with an additional 2 to 4 inches of rain expected in parts of Oregon. The region is advised to prepare for potential flooding and to seek safety as needed.
The weather will improve slightly by late Thursday and Friday, but another atmospheric river may hit the region by the weekend, prolonging the severe weather conditions. The consecutive atmospheric rivers have significantly increased the flooding risk, with the first bringing 7 to 9 inches of rain and the second reaching Level 5 intensity in northwestern Oregon. Warmer temperatures have also contributed to snowmelt, further exacerbating the flood risks.
Intensified Flood Risks from Continuous Atmospheric Rivers : Actionable Insights On EigenPrism
Report Templates
For all EigenPrism users, the forecast impact report template for the December floods is available. The pages of this report template get auto-updated with the latest available footprints:
US Flood Dec 2023 Forecast Impact Summary Report – Template
Subscribers of ICEYE can use this report template containing footprints from ICEYE on EigenPrism®, to quickly assess the impact of flooding:
US Flood Dec 2023 ICEYE Impact Summary Report -Template
Alternatively, users can also run analyses on the individual footprints mentioned below. Please note that these footprints are also present in the report templates mentioned above.
Event Footprints
All EigenPrism® users can assess the forecast using the following quick links:
- 72-Hr Forecast Freezing Rain Accumulation (90th Percentile) as of 2023-12-07
- 72-Hr Forecast Snow Accumulation (90th Percentile) as of 2023-12-07
- US Flood Outlook as of 2023-12-07
- WPC 3-Day Excessive Rainfall Outlook valid from 2023-12-06
- Landslide Potential as of 2023-12-06
- 5-day Flood Potential as of 2023-12-06
EigenPrism® users can assess the post-event impact using the following quick links:
- 72-hour observed snow accumulation as of 2023-12-07
Subscribers of ICEYE can use these real-time footprints on EigenPrism®, to quickly assess the impact of flooding:
ICEYE
- HeavyRain – Pacific Northwest (USA) 2023 – Flood Extent Footprint from ICEYE as of 2023-12-06
- HeavyRain – Pacific Northwesti (USA) 2023 – Flood Inundation Footprint from ICEYE as of 2023-12-06
Don’t have access to EigenPrism®?
Sign up for a trial account and access full impact reports of all events. Contact us and we’ll set up a trial account for you.
December 6 | Atmospheric River Continues to Impact Pacific Northwest
The Pacific Northwest is currently facing a severe weather crisis, with a powerful atmospheric river putting over 10 million people on flood alert. From Monday morning to Tuesday morning, this system has delivered over 8 inches of rain, significantly increasing flood risks in an already waterlogged region.
A landslide, triggered by the torrential downpour, triggered by the torrential downpour has disrupted critical Amtrak services between Seattle and Portland, underscoring the extensive infrastructure damage. Flood watches extend across the region, with the Olympic mountains in Washington expected to receive over a foot of rain and the Cascades bracing for 5 to 9 inches.
In Washington, the Skagit, Snoqualmie, and Stillaguamish rivers have reached major flood stages as of Tuesday morning, with forecasts predicting impacts on roads, farms, and homes. The Stillaguamish River has set a new record high at 21.34 feet, surpassing its 2010 record; notably, the threshold for major flood stage is 19 feet. The Weather Prediction Centre has issued a Level 2 of 4 slight risk for excessive rainfall on Tuesday, which will decrease to a Level 1 of 4 marginal risk by Wednesday.
Coastal areas are bracing for 3 to 5 inches of rain, while interior lowlands anticipate 1 to 3 inches. The latest forecast indicates continued heavy rainfall, with Oregon’s Cascade mountains, parts of southern Washington, and northwest California being particularly affected. The Weather Prediction Centre has issued a Level 2 of 4 slight risk for excessive rainfall on Tuesday, which will decrease to a Level 1 of 4 marginal risk by Wednesday.
Storm activity will diminish by Thursday, yet the region may face another atmospheric river by the weekend. This relentless series of atmospheric rivers, offering little respite, significantly contributes to the heightened risk of flooding and property damage throughout the Pacific Northwest.
Atmospheric River Continues to Impact Pacific Northwest: Actionable Insights on EigenPrism
To make timely decisions about this event, EigenPrism® users can assess the forecast using the following quick links:
- 72-Hr Forecast Freezing Rain Accumulation (90th Percentile) as of 2023-12-06
- 72-Hr Forecast Snow Accumulation (90th Percentile) as of 2023-12-06
- US Flood Outlook as of 2023-12-06
- WPC 3-Day Excessive Rainfall Outlook as of 2023-12-05
- 5-day Flood Potential as of 2023-12-05
- Landslide Potential as of 2023-12-05
EigenPrism® users can assess the post-event impact using the following quick links:
- 72-hour observed snow accumulation as of 2023-12-06
Don’t have access to EigenPrism®?
Sign up for a trial account and access full impact reports of all events. Contact us and we’ll set up a trial account for you.
