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Web Portal Changes: In Spring 2024, the Advanced Hydrologic Prediction Service (AHPS) hosted at will be replaced by the National Water Prediction Service (NWPS) at a repurposed A preview of NWPS is available here, where you can see your station hydrograph by replacing SSSSS with the station 5-character id:

Flood Inundation Mapping: Experimental real-time flood Inundation mapping services for 10% of the United States are now available via the NWS Map Viewer. Additional products and geospatial services depicting River Forecast Center and National Water Model forecasts continue to be accessible as described in the StoryMap here.

Please visit for more information.

Hydrograph River at a Glance Download
Green River (WA) at Howard Hanson Reservoir Inflow Discharge (kcfs)Stage (ft)Observed: 0.66 kcfs at 1:00AM Feb 25, 2024Observed: 0.68 kcfs at 2:00AM Feb 25, 2024Observed: 0.7 kcfs at 3:00AM Feb 25, 2024Observed: 0.73 kcfs at 4:00AM Feb 25, 2024Observed: 0.76 kcfs at 5:00AM Feb 25, 2024Observed: 0.79 kcfs at 6:00AM Feb 25, 2024Observed: 0.82 kcfs at 7:00AM Feb 25, 2024Observed: 0.87 kcfs at 8:00AM Feb 25, 2024Observed: 0.91 kcfs at 9:00AM Feb 25, 2024Observed: 0.94 kcfs at 10:00AM Feb 25, 2024Observed: 0.98 kcfs at 11:00AM Feb 25, 2024Observed: 1.02 kcfs at 12:00PM Feb 25, 2024Observed: 1.08 kcfs at 1:00PM Feb 25, 2024Observed: 1.13 kcfs at 2:00PM Feb 25, 2024Observed: 1.21 kcfs at 3:00PM Feb 25, 2024Observed: 1.27 kcfs at 4:00PM Feb 25, 2024Observed: 1.37 kcfs at 5:00PM Feb 25, 2024Observed: 1.46 kcfs at 6:00PM Feb 25, 2024Observed: 1.58 kcfs at 7:00PM Feb 25, 2024Observed: 1.69 kcfs at 8:00PM Feb 25, 2024Observed: 1.81 kcfs at 9:00PM Feb 25, 2024Observed: 1.9 kcfs at 10:00PM Feb 25, 2024Observed: 2.01 kcfs at 11:00PM Feb 25, 2024Observed: 2.1 kcfs at 11:59PM Feb 25, 2024Observed: 2.17 kcfs at 1:00AM Feb 26, 2024Observed: 2.22 kcfs at 2:00AM Feb 26, 2024Observed: 2.24 kcfs at 3:00AM Feb 26, 2024Highest Observation: 2.26 kcfs at 4:00AM Feb 26, 2024Highest Observation: 2.26 kcfs at 5:00AM Feb 26, 2024Highest Observation: 2.26 kcfs at 6:00AM Feb 26, 2024Observed: 2.23 kcfs at 7:00AM Feb 26, 2024Observed: 2.21 kcfs at 8:00AM Feb 26, 2024Observed: 2.17 kcfs at 9:00AM Feb 26, 2024Observed: 2.15 kcfs at 10:00AM Feb 26, 2024Observed: 2.12 kcfs at 11:00AM Feb 26, 2024Observed: 2.1 kcfs at 12:00PM Feb 26, 2024Observed: 2.06 kcfs at 1:00PM Feb 26, 2024Observed: 2.03 kcfs at 2:00PM Feb 26, 2024Observed: 2 kcfs at 3:00PM Feb 26, 2024Observed: 1.98 kcfs at 4:00PM Feb 26, 2024Observed: 1.95 kcfs at 5:00PM Feb 26, 2024Observed: 1.92 kcfs at 6:00PM Feb 26, 2024Observed: 1.88 kcfs at 7:00PM Feb 26, 2024Observed: 1.86 kcfs at 8:00PM Feb 26, 2024Observed: 1.84 kcfs at 9:00PM Feb 26, 2024Observed: 1.81 kcfs at 10:00PM Feb 26, 2024Observed: 1.78 kcfs at 11:00PM Feb 26, 2024Observed: 1.74 kcfs at 11:59PM Feb 26, 2024Observed: 1.72 kcfs at 1:00AM Feb 27, 2024Observed: 1.69 kcfs at 2:00AM Feb 27, 2024Observed: 1.68 kcfs at 3:00AM Feb 27, 2024Observed: 1.65 kcfs at 4:00AM Feb 27, 2024Observed: 1.62 kcfs at 5:00AM Feb 27, 2024Observed: 1.6 kcfs at 6:00AM Feb 27, 2024Observed: 1.58 kcfs at 7:00AM Feb 27, 2024Observed: 1.55 kcfs at 8:00AM Feb 27, 2024Observed: 1.54 kcfs at 9:00AM Feb 27, 2024Observed: 1.52 kcfs at 10:00AM Feb 27, 2024Observed: 1.51 kcfs at 11:00AM Feb 27, 2024Observed: 1.5 kcfs at 12:00PM Feb 27, 2024Observed: 1.47 kcfs at 1:00PM Feb 27, 2024Observed: 1.46 kcfs at 2:00PM Feb 27, 2024Observed: 1.46 kcfs at 3:00PM Feb 27, 2024Observed: 1.44 kcfs at 4:00PM Feb 27, 2024Observed: 1.43 kcfs at 5:00PM Feb 27, 2024Observed: 1.43 kcfs at 6:00PM Feb 27, 2024Observed: 1.41 kcfs at 7:00PM Feb 27, 2024Observed: 1.42 kcfs at 8:00PM Feb 27, 2024Observed: 1.41 kcfs at 9:00PM Feb 27, 2024Observed: 1.34 kcfs at 10:00PM Feb 27, 2024Observed: 1.48 kcfs at 11:00PM Feb 27, 2024USACEHHDW1(plotting QIIRZ) Graph Created (12:20AM Feb 28, 2024)ObservedLatest observed value: 1.48 kcfs at 11:00 PM PST 27-Feb-2024.
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Tabular Data (UTC)
Tabular Data (PST)
XML Data
RSS Files
Datum: Not Available
NOTE: River forecasts for this location take into account past and future precipitation. The stages/flows that will occur may be different if future rainfall is different than forecast.

Reliability of the Forecast: Based on current and forecast river, weather and reservoir conditions

NOTE: Forecasts for the Green River (WA) at Howard Hanson Reservoir are issued routinely year-round.

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Upstream Gauge - above Twin Camp Upstream Gauge Downstream Gauge Downstream Gauge - below Howard Hanson Dam
Flood Categories (in feet)
Not Available

Historic Crests
(1) 0.00 ft on 01/31/2003
(2) 0.00 ft on 01/18/2005
(3) 0.00 ft on 01/10/2006
(4) 0.00 ft on 11/12/2008
(5) 0.00 ft on 11/06/2006
(6) 0.00 ft on 01/07/2009

(P): Preliminary values subject to further review.

Recent Crests
(1) 0.00 ft on 01/07/2009
(2) 0.00 ft on 11/12/2008
(3) 0.00 ft on 11/06/2006
(4) 0.00 ft on 01/10/2006
(5) 0.00 ft on 01/18/2005
(6) 0.00 ft on 01/31/2003

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.
Zoom Level:16
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Gauge LocationGauge Map Marker
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.
About This Location Collapse

Latitude: 47.277048° N, Longitude: 121.785385° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame
Gauge Height Flood Stage Uses
NWS stage 0 ft Not Available Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)
(gauge height = flood stage)
Elevation information source
NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps
NGVD 29 0.0 ft Not Available Older USGS topographic maps, NGVD29 benchmarks
MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks
Other Not Available Not Available  

Current/Historical Observations:

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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.
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