Atlantic Coast at Chatham Harbor (IN MLLW)
Future / Actual / Minor
OWP 2.0 WWA Modal Title
01/11/2021, 10:04 PM UTC through 01/11/2021, 10:04 PM UTC
Sender
Sent
- Upstream gauge unavailableDownstream gauge unavailableWarning: no valid ratings curve available. Transformations to and from FEET/CFS/KCFS will not happen.No secondary data available. Transformations for Flow data and a secondary Y axis cannot be made at this time.
Traces and Thresholds Click to turn on/off display
Observed (OBS) 06/14/2025 12:06 AM EDTOfficial Forecast (FCST) 06/13/2025 4:08 PM EDTCATEGORY STAGE 
Major Flooding 13 ft Moderate Flooding 11.5 ft Minor Flooding 9 ft Action 8 ft Reliability of the Forecast:
NOTE: Forecasts are issued routinely year-round.
Stage may be affected by ice.
Please refer to our Coastal Hazard Message for specific information regarding Coastal Flood Watches, Warnings and Advisories. Actual impacts from any coastal 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 here for additional storm surge information.
During a Tropical Storm or Hurricane Watch or Warning, inundation mapping provided by the National Hurricane Center (go to the web site and select the storm of interest) reflects a reasonable worst case scenario. The forecast above is the total water forecast that is most likely to occur.
National Water Model Hydrograph
Official NWS streamflow forecasts are produced by NWS hydrologic forecasters for river gauge locations using hydrologic models which are calibrated to that location. This process considers additional guidance and information, including local expertise and experience, to produce the best forecast possible. The NWM output provides supplemental guidance to NWS forecasters and should not be considered an official NWS river forecast.
Flood Impacts
- 13 - Significant flooding of low lying coastal areas is expected from Chatham northward along the east shore of the Cape. Immediate coastal roads will be flooded for a time near high tide and significant beach erosion is likely. Localized evacuations of the most vulnerable coastal areas may be required.
- 9 - Flooding of lowest lying coastal areas is likely. Some immediate coastal roads may be flooded nearest the time of high tide. Large swells may also produce some localized beach erosion.
Gauge Info
| Coordinates | 41.6885, -69.9510 |
| RFC | NERFC |
| State | MA |
| WFO | BOX |
| County | Barnstable |
| Data Provider(s) | |
| US Geological Survey | USGS--Water Resources of the United States |
Gauge Location
Recent Crests
| 1. | 8.54 ft | on 12-23-2022 |
| 2. | 8.81 ft | on 01-30-2018 |
| 3. | 8.63 ft | on 02-08-2016 |
| 4. | 9.76 ft | on 01-03-2014 |
| 5. | 8.80 ft | on 03-08-2013 |
Recent Crests
| 1. | 8.54 ft | on 12-23-2022 |
| 2. | 8.81 ft | on 01-30-2018 |
| 3. | 8.63 ft | on 02-08-2016 |
| 4. | 9.76 ft | on 01-03-2014 |
| 5. | 8.80 ft | on 03-08-2013 |
| 6. | 8.78 ft | on 03-07-2013 |
| 7. | 9.69 ft | on 02-09-2013 |
| 8. | 8.73 ft | on 12-27-2010 |
| 9. | 8.75 ft | on 03-01-2010 |
| 10. | 8.78 ft | on 02-26-2010 |
| 11. | 8.77 ft | on 01-02-2010 |
Historic Crests
| 1. | 9.76 ft | on 01-03-2014 |
| 2. | 9.69 ft | on 02-09-2013 |
| 3. | 8.81 ft | on 01-30-2018 |
| 4. | 8.80 ft | on 03-08-2013 |
| 5. | 8.78 ft | on 03-07-2013 |
Historic Crests
| 1. | 9.76 ft | on 01-03-2014 |
| 2. | 9.69 ft | on 02-09-2013 |
| 3. | 8.81 ft | on 01-30-2018 |
| 4. | 8.80 ft | on 03-08-2013 |
| 5. | 8.78 ft | on 03-07-2013 |
| 6. | 8.78 ft | on 02-26-2010 |
| 7. | 8.77 ft | on 01-02-2010 |
| 8. | 8.75 ft | on 03-01-2010 |
| 9. | 8.73 ft | on 12-27-2010 |
| 10. | 8.63 ft | on 02-08-2016 |
| 11. | 8.54 ft | on 12-23-2022 |
Gauge Photos
No Images Found
Probability Information
No Images Available
Unique Local Info
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Potential Tide Levels Used to Estimate the Chance of Flooding and the Range of Possible Tide Levels |
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| GFS Based Guidance (ETSS) | GEFS Based Guidance (P-ETSS) | NAEFS Based Guidance (P-ETSS) |
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Note: Use the official hydrograph at the top of this web page for tide levels within the next 72 hours.
The Potential Tide Level graphics above are from an EXPERIMENTAL web site. It is supported on an 8x5 basis, and has no guarantee of availability in the future. Please see information HERE to understand the strengths and weakness of the Potential Tide Level graphics. Click individual graphics to enlarge.
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.