NOAA 50th Anniversary
Office of Coast Survey
National Oceanic and Atmospheric Administration
U.S. Department of Commerce

NOAA's nowCOAST® provides access to National Weather Service’s new storm surge watches and warnings

NOAA's nowCOAST®, a GIS-based online web mapping service that provides frequently updated weather and ocean observations, analyses, imagery, and ocean model forecast guidance, along with inland, coastal and marine weather warnings and forecasts, now provides access to the National Weather Service’s (NWS) new storm surge watches and warnings. The NWS storm surge watches and warnings highlight areas along the Gulf and Atlantic coasts of the continental United States that have a significant risk of life-threatening inundation from an ongoing or potential tropical cyclone, a subtropical cyclone, or a post-tropical cyclone.

Additionally, the depiction of NWS tropical cyclone forecast information on the nowCOAST map service, wwa_meteoceanhydro_longduration_hazards_time, changed. Changes include:

  • The 5-day cone of uncertainty representing the uncertainty in the probable forecast track of a tropical cyclone will be depicted in semi-transparent white.
  • The forecast positions for remnants, post tropical, tropical depression, tropical storms and hurricanes will be depicted with new symbols and in black.
  • The new symbol for hurricanes will contain the forecasted Saffir-Simpson Hurricane Wind Scale Category (i.e. 1, 2, 3, 4 or 5).
  • The observed (best track) positions for tropical cyclones will be depicted in white.
  • The forecast track for tropical cyclones will be depicted with a dashed blue line.
  • The tropical storm warnings along the immediate coastline will be depicted with a solid blue line.

nowCOAST is an ArcGIS-based web mapping application developed by the Office of Coast Survey’s Coast Survey Development Laboratory and is hosted on NOAA’s 24 x7 high availability Integrated Dissemination Program IT infrastructure operated the NWS National Centers for Environmental Prediction’s Central Operations.

Detailed information on the NWS Storm Surge Watches and Warnings can be found at and