National Weather Service Advanced Hydrologic Prediction Service

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This probabilistic forecast is issued by the Northwest River Forecast Center.

	Hydrograph			River at a Glance			Download			Probability Information Weekly Chance of Exceeding Levels Chance of Exceeding Levels During Entire Period Short-term Probabilistic Guidance (Experimental)

About this graph

Forecasts for the Chehalis River near Grand Mound are issued routinely year-round.

Return to Area Map

Upstream Gauge

Zoom Level:13

Flood Categories (in feet)

Major Flood Stage:	144
Moderate Flood Stage:	142.5
Flood Stage:	141
Action Stage:	138.5
Low Stage (in feet):	-9999

Historic Crests
(1) 147.26 ft on 12/04/2007
(2) 142.88 ft on 01/14/2021 (P)
(3) 142.68 ft on 12/22/2019 (P)
(4) 142.59 ft on 01/04/2021 (P)
(5) 142.41 ft on 01/08/2020 (P)
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 141.41 ft on 11/13/2021 (P)
(2) 142.88 ft on 01/14/2021 (P)
(3) 142.59 ft on 01/04/2021 (P)
(4) 142.41 ft on 01/08/2020 (P)
(5) 142.68 ft on 12/22/2019 (P)
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.

	Gauge Location	Disclaimer
Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.

Flood Impacts & Photos

If you notice any errors in the below information, please contact our Webmaster
146	the Chehalis River in Thurston County will cause severe near record flooding, with deep and swift flood waters inundating the Independence Valley. Flooding will occur all along the river including headwaters, tributaries, and other streams within and near the Chehalis River Basin.
144.5	the Chehalis River in Thurston County will cause major flooding, inundating roads and farm lands in Independence Valley. Deep and swift flood waters will cover SR-12 and James, Independence and Moon Roads. Flooding will occur all along the river including headwaters, tributaries, and other streams within and near the Chehalis River Basin.
142.5	the Chehalis River in Thurston County will flood several roads in Independence Valley with swiftly moving water including SR-12 and James, Independence, Moon and Anderson Roads. Flood waters will cut off access to and from Chehalis Reservation and inundate nearby farm lands. Some residential structures may be threatened.
141	the Chehalis River in Thurston County will flood several roads in Independence Valley including James Road, Independence Road, and Moon road. Flood waters will also cover nearby farm lands.
139.5	the Chehalis River in Thurston County will locally spill out of its banks into nearby fields and over a few roads.

Other Real-time and/or Archive Data Sources:

U.S. Geological Survey (USGS) Data and Site Info for Grand Mound

Additional Information

Chehalis River Basin Flood Authority's Early Warning System:http://lewiscountywa.gov/chehalis-river-basin-flood-authority

Collaborative Agencies

The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.

NWS Information

National Weather Service
Seattle Weather Forecast Office
7600 Sandpoint Way NE
Seattle, WA 98115-6349
(206) 526-6087
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Page last modified: 30-Oct-2020 4:07 PM

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