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Local weather forecast by
What is AHPS?
Weather Forecast Office Philadelphia/Mount Holly, NJ
Middle Atlantic River Forecast Center
Winter Storm Watch
River at a Glance
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About this graph
Tabular Data (UTC)
Tabular Data (EST)
Datum: Not Available
Coastal Hazard Message
for specific information regarding Coastal Flood Watches, Warnings and Advisories. Flood impacts are based on long-term averages. Actual impacts from any tidal flooding event may vary due to factors such as rainfall, wave action, and the number of tide cycles during which there is an onshore flow. During tropical cyclones, please refer
for additional storm surge information.
National Hurricane Center
reflects a plausible worst case scenario. The experimental forecast above is the total water forecast that is expected to occur.
Forecasts for the Delaware Bay at Reedy Point are issued routinely year-round.
Vertical Datum references a tidal datum (MLLW)...for more information see
Tides and Currents
Scale to Flood Categories
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Flood Categories (in feet)
Major Flood Stage:
Moderate Flood Stage:
Low Stage (in feet):
(1) 9.24 ft on 04/16/2011
(2) 9.19 ft on 12/21/2012
(3) 9.10 ft on 10/30/2012
(4) 8.88 ft on 10/25/1980
(5) 8.66 ft on 09/19/2003
Show More Historic Crests
: Preliminary values subject to further review.
(1) 8.62 ft on 09/10/2018
(2) 8.25 ft on 05/01/2014
(3) 9.19 ft on 12/21/2012
(4) 9.10 ft on 10/30/2012
(5) 9.24 ft on 04/16/2011
Show More Recent Crests
: Preliminary values subject to further review.
Low Water Records
(1) -4.01 ft on 04/07/1982
(2) -3.83 ft on 11/21/1989
(3) -3.76 ft on 03/02/2018
(4) -3.60 ft on 03/08/1986
(5) -3.54 ft on 02/25/1990
Show More Low Water Records
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
(Mean Lower Low Water (MLLW)) The level reached on April 16, 2011.
(MLLW) MAJOR FLOODING. At this level, widespread roadway flooding begins near the bay, the river and the tidal tributaries in New Castle County DE and Salem County NJ. Vulnerable homes and businesses may be damaged as water levels rise further above this threshold. Numerous roads become impassable and some neighborhoods may be isolated. The flood waters become a danger to anyone who attempts to cross on foot or in a vehicle.
(MLLW) MODERATE FLOODING. At this level, additional roadways near the bay, the river and the tidal tributaries in New Castle County DE and Salem County NJ begin to flood. Lives may be at risk when people put themselves in harm's way. Some damage to vulnerable structures may begin to occur. COASTAL FLOOD WARNING LEVEL.
(MLLW) Flooding begins along East 12th Street and along the south bank of the Christina River in Wilmington DE. Flooding begins where the Red Clay Creek, the White Clay Creek and the Christina River meet. The area is just to the west and northwest of the New Castle Airport and it includes the communities of Christiana, Glenville and Stanton DE. Flooding begins along the Appoquinimink River in Odessa DE. Flooding begins along NJ Route 49 and along Quinton-Alloway Road in Quinton Township NJ.
(MLLW) Flooding begins along Oldmans Creek at US Route 130 and near Pedrickton NJ. Flooding begins along Delaware Ave and South Broad Street in Penns Grove NJ and along Delaware Ave, Spring Street and Briar Ave in Carneys Point NJ. Flooding begins along Riviera Drive and Hook Road in Pennsville Township NJ. Flooding begins along Pointers-Auburn Road and NJ Route 45 in Mannington Township NJ. Flooding begins along Sinnicksons Landing Road in Elsinboro Township NJ and along NJ Routes 45 and 49 in Salem.
(MLLW) COASTAL FLOOD ADVISORY LEVEL.
(MLLW) Flooding begins in New Castle DE along the Strand and in the Dobbinsville section. Flooding begins along the section of DE Route 9 just to the south of New Castle DE and around the approaches to the DE Route 9 bridge over the Red Lion Creek. Flooding begins in Delaware City DE including the area around the 5th Street bridge. Flooding begins in Port Penn, Augustine Beach and Bay View Beach DE. Flooding begins around the approaches to the DE Route 9 bridge over the Appoquinimink River.
(MLLW) MINOR FLOODING.
About This Location
Latitude: 39.551389° N, Longitude: 75.567778° W, Horizontal Datum: NAD83/WGS84
Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
(gauge height = 0)
(gauge height = flood stage)
Elevation information source
Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps
Older USGS topographic maps, NGVD29 benchmarks
Older USGS topographic maps, MSL benchmarks
NAVD88 to MHHW conversion from NOAA Vertical Datum Transformation (VDatum)
All gage data is referenced in MLLW. During winter months, cold and ice may result in inaccurate real-time stages. Adjustments or deletions of this data can only be done after detailed analysis.
River Forecast Centers
River Stage Summary
Automated Flood Warning Systems
Inundation Mapping Locations
NWS Precipitation and River Forecasting
AHPS Iframes for Developers
Mobile iNWS for emergency management
Flood Damage Costs/Fatalities in the US, 1903 - 2014
AHPS Web Brochure
Ensemble River Forecasts
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
National Weather Service
Philadelphia/Mount Holly Weather Forecast Office
732 Woodlane Road
Mount Holly, NJ 08060-9615
Page last modified: 21-Dec-2016 10:38 PM