The Center for Operational Products and Services (CO-OPS) Storm QuickLook product provides a synopsis of near real-time oceanographic and meteorological observations at locations affected by a tropical cyclone. It is initiated when a National Weather Service (NWS) storm center issues a tropical storm or hurricane warning for the U.S. or its island possessions. Advisories may be initiated sooner if oceanographic conditions warrant. The product is updated four times per day (approximately one hour after standard NWS public advisories are issued) unless special circumstances, such as storm landfall, dictate otherwise. When active, a link to the Storm QuickLook product is displayed on CO-OPS web pages and is frequently linked on other NOAA websites and NOAA social media pages.
The Storm QuickLook product contains 3 main sections. A map is displayed, highlighting the location of NOS tide gauges in reference to storm information such as track and intensity and current satellite imagery. The storm analysis section provides a brief overview of present oceanographic and meteorological conditions, links to additional CO-OPS products and the latest NWS public advisory. Below the map and storm analysis, time-series plots of water level and meteorological data at selected locations are updated in near real-time every 6 minutes. These data undergo continuous review by the CO-OPS quality control system, CORMS. The primary vertical reference datum for water level data is Mean Higher High Water (MHHW); however, users can change the reference datum to Mean Lower Low Water (MLLW); Mean Sea Level (MSL) or the North American Vertical Datum of 1988 (NAVD88), where available. Water level plots contain a line denoting Mean Higher High Water to provide an approximate level at which flooding inundation may occur. The Historical Maximum Water Level and peak water level observed over the past 24 are also displayed. Meteorological data highlighted include winds, barometric pressure, and in some instances air and water temperature.
In addition to generating the Storm QuickLook product, following significant storms, CO-OPS will also issue post-storm data reports displaying verified water level measurements during the storm and highlighting maximum storm tide and storm surge at locations affected by the storm. The below graphic highlights the difference between storm tide and storm surge. The National Hurricane Center provides a detailed description of storm surge and storm tide at http://www.nhc.noaa.gov/ssurge/index.shtml.
Storm tides are a combination of storm surge and astronomical tides together with wind driven wave setup and any anomalies due to regional atmospheric conditions.
Storm Surge: The onshore rush of sea or lake water caused by the high wind and the low pressure centers associated with a landfalling hurricane or other intense storm. The amplitude of the storm surge at any given location is dependent upon the orientation of the coast line with the storm track, the intensity, size and speed of the storm, and the local bathymetry. In practice, storm surge is usually estimated by subtracting the normal or astronomical tide from the observed storm tide at tide stations (see Residual on QuickLook plots). This difference between observed storm tides and astronomical tide can have other components such as regional elevated mean sea levels in the Gulf of Mexico due to the Loop Current, elevated sea levels on the West Coast due to El Niño Southern Oscillation (ENSO), or local elevated sea levels due to river runoff in tidal rivers.
Storm Tide:
The maximum water level elevation measured by a water level station during storm events. Depending on location, the storm tide is the potential combination of storm surge, local astronomical tide, regional sea level variations and river runoff during storm events. Since wind generated waves ride on top of the storm surge (and are not included in the definition), the total instantaneous elevation may greatly exceed the predicted storm surge plus astronomical tide. It is potentially catastrophic, especially on low lying coasts with gently sloping offshore topography. NOAA measures storm tide elevations from a common reference datum of Mean Lower Low Water (MLLW) which is the U.S Nautical Chart Datum.
