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Weather Forecast Office (Baltimore/Washington) Sterling, VA

Middle Atlantic River Forecast Center

Coastal Flood Advisory

Hydrograph

River at a Glance

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Inundation Mapping

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Printable Image About this graph Tabular Data (UTC) Tabular Data (EDT) Datum: NAVD88 Metadata

NOTE:  Please refer to Coastal Flood Advisories and Warnings for official water level forecasts during periods of coastal flooding.  During tropical cyclones, please refer here for additional storm surge information. NOTE: Forecasts for the Potomac River at Alexandria are issued routinely year-round.

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Upstream Gauge

Downstream Gauge

Flood Categories (in feet) Major Flood Stage: 6.6 Moderate Flood Stage: 4.2 Flood Stage: 3.3 Action Stage: 2.5 Low Stage (in feet): -9999 Historic Crests (1) 8.66 ft on 09/19/2003 (2) 7.40 ft on 03/19/1936 (3) 5.99 ft on 10/29/2021 (P) (4) 5.06 ft on 04/16/2011 (5) 5.04 ft on 09/10/2018 Show More Historic Crests (P): Preliminary values subject to further review. Recent Crests (1) 4.44 ft on 09/24/2023 (P) (2) 4.53 ft on 04/07/2023 (P) (3) 4.27 ft on 01/17/2022 (P) (4) 5.99 ft on 10/29/2021 (P) (5) 3.87 ft on 05/01/2020 (P) Show More Recent Crests (P): Preliminary values subject to further review. Low Water Records Currently none available. For more information on your flood risk go to www.floodsmart.gov. Show FEMA's National Flood Hazard Layers FEMA's National Flood Hazard Layers not showing? Why aren't the FEMA National Flood Hazard Layers showing on the ESRI Map? Possible reasons: There are no FEMA National Flood Hazard Layers for the location which you are viewing on ESRI Maps. The FEMA Web Mapping Service (WMS) is down. Note: Your zoom level may have changed. ESRI's zoom levels must be between 14 and 16 to show National Flood Hazard layers.

Zoom Level:14 Legend FEMA Layer 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

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9	Flooding is occurring nearshore at Joint Base Anacostia Bolling near the marina and at the Naval Research Lab. Daingerfield Island is completely flooded. Union Street is flooded for almost its entire length in Alexandria. Dozens of structures are impacted. Widespread backwater flooding is affecting Huntington and Belle View.
7.5	On Joint Base Anacostia Bolling, floodwaters cross Giovanni Way with structures affected. Daingerfield Island is almost totally underwater. In Alexandria, flooding reaches the east end of Madison Street with structures flooded. Union Street is flooded between Queen Street and Duke Street with numerous structures impacted. A large section of the George Washington Parkway is flooded and closed both north and south of Old Town Alexandria.
6.5	Water approaches the George Washington Parkway near Daingerfield Island and Belle Haven. Flooding is occurring near the Joint Base Anacostia Bolling marina. Significant flooding is occurring along Union Street in Old Town Alexandria, along with nearby streets. Flooding is also occurring further south at Jones Point.
5.5	Floodwaters reach about a block and a half inland at King Street and cover several blocks of Union Street in Alexandria.
5	Flooding begins in the vicinity of the Joint Base Anacostia Bolling marina. Access to the Daingerfield Island area is cut off due to flooding. Several parks along the Alexandria waterfront are flooded. Union Street is flooded between Wales Alley and Thompson Alley. Lower portions of King Street, Prince Street, and Strand Street are flooded. Water approaches the southern tip of Lee Street.
4.5	Flooding is ongoing at several businesses near the intersection of King Street and Union Street.
4	Water approaches buildings near the intersection of King Street and Union Street. This flooding will be slightly more widespread in a tidal flood than a freshwater flood.
3.75	Union Street is covered by water near King Street.
3.25	Water covers the easternmost end of King Street.
3.1	Water reaches the curb near the intersection of King Street and Strand Street.
2.7	Water begins to pool near the corner of Strand Street and Wales Alley in Alexandria.

About This Location

Latitude: 38.805278° N, Longitude: 77.038333° W, Horizontal Datum: NAD83/WGS84 River Stage Reference Frame Gauge Height Flood Stage Uses NWS stage 0 ft 3.3 ft 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 0.00 3.10 Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps NGVD 29 0.75 3.85 Older USGS topographic maps, NGVD29 benchmarks MSL -0.18 2.92 Older USGS topographic maps, MSL benchmarks Other 1.40 4.50   Current/Historical Observations: U.S. Geological Survey (USGS) Data and Site Info for Alexandria

Resources

Hydrologic Resources Text Products Past Precipitation Forecast Precipitation River Forecast Centers River Stage Summary Automated Flood Warning Systems Inundation Mapping Locations

Additional Resources Area Hydrographs NWS Precipitation and River Forecasting AHPS Iframes for Developers Mobile iNWS for emergency management Snow Information Ensemble River Forecasts Hourly Precipitation

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 (Baltimore/Washington) Sterling Weather Forecast Office 43858 Weather Service Rd. Sterling, VA 20166 (571) 888-3500 Ask Questions/Webmaster Page last modified: 2-Nov-2020 7:30 PM Disclaimer Credits Glossary Privacy Policy About Us Career Opportunities