National Weather Service Advanced Hydrologic Prediction Service

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Web Portal Changes: The Advanced Hydrologic Prediction Service (AHPS) hosted at https://water.weather.gov will be replaced by the National Water Prediction Service (NWPS), with a target of March 2024. Existing AHPS content and features will be preserved and expanded within NWPS.

Experimental National Water Center Products: Flood Inundation Mapping services are now available for 10% of the U.S. population. Please visit https://www.weather.gov/owp/operations for more information. The National Hydrologic Discussion, Area Hydrologic Discussion, Flood Hazard Outlook, and real-time geospatial services depicting River Forecast Center and National Water Model forecasts, continue to be accessible via the URL above, as described in the StoryMap here.

Weather Forecast Office Seattle, WA

Northwest River Forecast Center

Hydrograph

River at a Glance

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About this graph

Tabular Data (UTC)

Tabular Data (PDT)

Datum: NGVD29

Metadata

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 Snoqualmie River at Snoqualmie Falls are issued routinely year-round.

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Upstream Gauge

Downstream Gauge

Flood Categories (in KCFS)

Major Flood Flow:	41
Moderate Flood Flow:	31
Flood Flow:	20
Action Flow:	15
Low Stage (in feet):	-9999

Historic Crests
(1) 78,800 cfs on 11/24/1990
(2) 61,000 cfs on 11/23/1959
(3) 60,700 cfs on 01/07/2009
(4) 58,100 cfs on 11/24/1986
(5) 54,900 cfs on 11/07/2006 (P)
(6) 53,800 cfs on 12/02/1977
(7) 51,800 cfs on 12/03/1975
(8) 51,700 cfs on 02/09/1996
(9) 50,200 cfs on 11/29/1995 (P)
(10) 50,100 cfs on 01/05/2015
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 36,700 cfs on 11/05/2022 (P)
(2) 25,800 cfs on 01/12/2022 (P)
(3) 22,000 cfs on 01/13/2021 (P)
(4) 37,500 cfs on 02/01/2020 (P)
(5) 19,700 cfs on 12/30/2018 (P)
(6) 28,100 cfs on 11/23/2017 (P)
(7) 23,580 cfs on 11/22/2017 (P)
(8) 33,880 cfs on 10/22/2017 (P)
(9) 21,900 cfs on 10/20/2016 (P)
(10) 24,800 cfs on 02/15/2016 (P)
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.

Zoom Level:16

	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
70000	the Snoqualmie River will cause severe near record flooding from the town of Snoqualmie downstream through Fall City. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Snoqualmie River Basin. This river level on the Snoqualmie corresponds to a phase 4 flood in the King County flood system.
55000	the Snoqualmie River will cause major flooding from the town of Snoqualmie downstream through Fall City...inundating most of the farm land in the flood plain...some residential areas...and many roads. Flood waters will be deep and swift in some areas. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Snoqualmie River Basin. This river level on the Snoqualmie corresponds roughly to a phase 4 flood in the King County flood system.
41000	the Snoqualmie River will cause major flooding from the town of Snoqualmie downstream through Fall City...inundating most of the farm land in the flood plain...some residential areas...and many roads. Flood waters will be deep and swift in some areas. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Snoqualmie River Basin. This river level on the Snoqualmie corresponds roughly to a phase 4 flood in the King County flood system.
30000	the Snoqualmie River will cause widespread flooding of pasture lands and roads along the river from the town of Snoqualmie downstream through Fall City. Roads that may become flooded include Fall City-Carnation...Tolt Hill...and Novelty Flats Roads. This river level on the Snoqualmie corresponds roughly to a phase 3 flood in the King County flood system.
20000	the Snoqualmie River will cause widespread flooding of pasture lands and roads along the river from the town of Snoqualmie downstream through Fall City. Roads that may become flooded include Fall City-Carnation...Tolt Hill...and Novelty Flats Roads. This river level on the Snoqualmie corresponds roughly to a phase 3 flood in the King County flood system.
12000	the Snoqualmie River will spill over its banks between the town of Snoqualmie and Fall City...covering pasture lands and several roads along the river. This river level on the Snoqualmie corresponds roughly to a phase 2 flood in the King County flood system.

About This Location

Latitude: 47.545012° N, Longitude: 121.842336° W, Horizontal Datum: NAD27

River Stage Reference Frame	Gauge Height	Flood Stage	Uses
NWS flow	Not Available	Not Available	Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum	Elevation (gauge height = 0)	Elevation (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	120 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:

U.S. Geological Survey (USGS) Data and Site Info for Snoqualmie Falls

Resources

Hydrologic Resources

Additional Resources

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: 2-Nov-2020 7:27 PM

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