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Extreme Water Levels from CO-OPS

Published by Center for Operational Oceanographic Products and Services | National Oceanic and Atmospheric Administration, Department of Commerce | Catalog Last Checked: May 10, 2026 at 09:08 AM | Dataset Last Updated: January 01, 2013 at 12:00 AM
Extremely high or low water levels at coastal locations are an important public concern and a factor in coastal hazard assessment, navigational safety, and ecosystem management. The probability that water levels will exceed a given elevation is based on a statistical analysis of historical extremely high and low water levels. This product provides annual exceedance probability levels for select Center for Operational Oceanographic Products and Services (CO-OPS) water level stations with at least 30 years of data. When used in conjunction with real-time station data, exceedance probability levels can be used to evaluate current conditions and determine whether a rare event is occurring. This information may also be instrumental in planning for the possibility of dangerously high or low water events at a local level. The extreme levels measured by the CO-OPS tide gauges during storms are called storm tides, which are the total observed seawater level during a storm, resulting from the combination of storm surge and the astronomical tide. They do not include wave runup, the movement of water up a slope. Therefore, the 1% annual exceedance probability levels do not necessarily correspond to the Base Flood Elevations (BFE) defined by the Federal Emergency Management Administration (FEMA), which are the basis for the National Flood Insurance Program. The 1% annual exceedance probability levels more closely correspond to FEMA's Still Water Flood Elevations (SWEL). The peak levels from tsunamis, which can cause high-frequency fluctuations at some locations, have not been included in this statistical analysis due to their infrequency during the periods of historic record.

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EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > COMPOUND EXTREME EVENTS EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > EXTREME WEATHER EARTH SCIENCE > LAND SURFACE > GEOMORPHIC LANDFORMS/PROCESSES > COASTAL PROCESSES > FLOODING EARTH SCIENCE > OCEANS EARTH SCIENCE > OCEANS > COASTAL PROCESSES > SEA SURFACE HEIGHT EARTH SCIENCE > OCEANS > COASTAL PROCESSES > TIDAL HEIGHT EARTH SCIENCE > OCEANS > MARINE ENVIRONMENT MONITORING EARTH SCIENCE > OCEANS > TIDES

Complete Metadata
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describedBy https://tidesandcurrents.noaa.gov/publications/CO-OPS_Measurement_Spec.pdf
describedByType application/octet-steam
description Extremely high or low water levels at coastal locations are an important public concern and a factor in coastal hazard assessment, navigational safety, and ecosystem management. The probability that water levels will exceed a given elevation is based on a statistical analysis of historical extremely high and low water levels. This product provides annual exceedance probability levels for select Center for Operational Oceanographic Products and Services (CO-OPS) water level stations with at least 30 years of data. When used in conjunction with real-time station data, exceedance probability levels can be used to evaluate current conditions and determine whether a rare event is occurring. This information may also be instrumental in planning for the possibility of dangerously high or low water events at a local level. The extreme levels measured by the CO-OPS tide gauges during storms are called storm tides, which are the total observed seawater level during a storm, resulting from the combination of storm surge and the astronomical tide. They do not include wave runup, the movement of water up a slope. Therefore, the 1% annual exceedance probability levels do not necessarily correspond to the Base Flood Elevations (BFE) defined by the Federal Emergency Management Administration (FEMA), which are the basis for the National Flood Insurance Program. The 1% annual exceedance probability levels more closely correspond to FEMA's Still Water Flood Elevations (SWEL). The peak levels from tsunamis, which can cause high-frequency fluctuations at some locations, have not been included in this statistical analysis due to their infrequency during the periods of historic record.
distribution 
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identifier https://data.noaa.gov/waf/NOAA/nos/coops/iso/xml/69876.xml
issued 2013-01-01T00:00:00.000+00:00
keyword 
                                            [
  "EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > COMPOUND EXTREME EVENTS",
  "EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > EXTREME WEATHER",
  "EARTH SCIENCE > LAND SURFACE > GEOMORPHIC LANDFORMS/PROCESSES > COASTAL PROCESSES > FLOODING",
  "EARTH SCIENCE > OCEANS",
  "EARTH SCIENCE > OCEANS > COASTAL PROCESSES > SEA SURFACE HEIGHT",
  "EARTH SCIENCE > OCEANS > COASTAL PROCESSES > TIDAL HEIGHT",
  "EARTH SCIENCE > OCEANS > MARINE ENVIRONMENT MONITORING",
  "EARTH SCIENCE > OCEANS > TIDES",
  "EARTH SCIENCE > OCEANS > TIDES > STORM SURGE",
  "EARTH SCIENCE > OCEANS > TIDES > TIDAL HEIGHT",
  "EARTH SCIENCE > OCEANS > TIDES > TIDAL RANGE",
  "CONTINENT",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALABAMA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > CALIFORNIA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > CONNECTICUT",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > DELAWARE",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > DISTRICT OF COLUMBIA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > FLORIDA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > GEORGIA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > HAWAII",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > LOUISIANA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MAINE",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MARYLAND",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MASSACHUSETTS",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MISSISSIPPI",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NEW HAMPSHIRE",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NEW JERSEY",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NEW YORK",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NORTH CAROLINA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > OREGON",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > PENNSYLVANIA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > RHODE ISLAND",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > SOUTH CAROLINA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > TEXAS",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > VIRGINIA",
  "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > WASHINGTON",
  "OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > BERMUDA",
  "OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA",
  "OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA > PUERTO RICO",
  "OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA > VIRGIN ISLANDS",
  "OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > GULF OF AMERICA",
  "OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > AMERICAN SAMOA",
  "OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > HAWAIIAN ISLANDS",
  "OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > JOHNSTON ATOLL",
  "OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > MIDWAY ATOLL",
  "OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > WAKE ISLAND",
  "OCEAN > PACIFIC OCEAN > WESTERN PACIFIC OCEAN > MICRONESIA > GUAM",
  "OCEAN > PACIFIC OCEAN > WESTERN PACIFIC OCEAN > MICRONESIA > MARSHALL ISLANDS",
  "ACOUSTIC SOUNDERS",
  "PRESSURE SENSORS > PRESSURE SENSORS",
  "TIDE GAUGES > TIDE GAUGES",
  "WATER LEVEL GAUGES > WATER LEVEL GAUGES",
  "GOES > NOAA Geostationary Operational Environmental Satellites",
  "Coastal Sea LevelStations",
  "NWLON > National Water Level Observation Network",
  "NWLON station",
  "PORTS > Physical Oceanographic Real-Time System",
  "coastal monitoring",
  "storm tide",
  "tides and currents",
  "water level predictions",
  "Coastal U.S. territories",
  "Coastal United States",
  "Gulf of Mexico",
  "Microwave Water Level (MWWL) Sensor",
  "DOC/NOAA/NOS/CO-OPS > Center for Operational Oceanographic Products and Services, National Ocean Service, NOAA, U.S. Department of Commerce",
  "CO-OPS Metadata Library"
]
landingPage https://www.fisheries.noaa.gov/inport/item/69876
language 
                                            []
license https://creativecommons.org/publicdomain/zero/1.0/
modified 2013-01-01T00:00:00.000+00:00
publisher 
                                            {
  "name": "Center for Operational Oceanographic Products and Services",
  "@type": "org:Organization"
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rights otherRestrictions, unclassified
spatial 180.0,-14.3,-180.0,61.3
temporal 2013-01-01T00:00:00+00:00/2013-01-01T00:00:00+00:00
title Extreme Water Levels from CO-OPS

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