NOUS41 KWBC DDHHHH PNSWSH Public Information Statement National Weather Service Headquarters Washington DC 820 AM EDT Tue Apr 17 2012 To: Subscribers: -Family of Services -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPORT Other NWS Partners and NWS Employees From: David Soroka Acting Chief, Marine and Coastal Services Branch Subject: Soliciting comments for Experimental Probabilistic Tropical Cyclone Inundation Guidance Products through November 30, 2012 As part of a long term effort to improve communications on storm surge and to reduce confusion among users with the various tidal and geodetic vertical datums, the NWS is providing storm surge information and guidance in terms of feet above ground level, i.e., inundation. Effective June 1, 2012, and continuing through November 30, 2012, NWS is seeking user feedback on Experimental Probabilistic Tropical Cyclone Inundation Guidance Products. The Experimental Tropical Cyclone Inundation Guidance products consist of two suites of probabilities for the Gulf of Mexico and Atlantic coastal areas: 1. Probabilities, in percent, of inundation exceeding 0 through 20 feet above ground level, at 1 foot intervals(e.g., the probabilities in percent, of inundation exceeding 0 feet, 1 feet, 2 feet, ... 20 feet). 2. Probabilities of inundation heights (above ground level) being exceeded. The suite of products range from 10 to 50 percent, at 10 percent intervals. Each of the probabilities mentioned above will be provided out to 78 hours as a cumulative probability, defined as the overall probability the event will occur at each grid cell from the start of the run until some specified time (e.g., 0-6 hours, 0-12, 0-18, etc.) and as an incremental probability, defined as the probability the event will occur sometime during the specified forecast period (e.g., 0-6 hours, 6-12, 12-18, etc.,) at each grid cell. The current series of probabilistic inundation products do not account for tide, waves, and fresh water, i.e., precipitation runoff and river inflow. The products are based upon an ensemble of Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model runs using the National Hurricane Center (NHC) official advisory and accounts for track, size, and intensity errors based on historical errors. NWS is also developing a next generation of probabilistic tropical cyclone inundation guidance products, which will incorporate tide. A Technical Information Notice will be sent before the commencement of these products. The probabilistic inundation products will only be generated when hurricane watches and/or warnings are in effect for the Atlantic and Gulf Coasts of the continental United States. When produced, graphical versions of the products will be posted online at: http://www.weather.gov/mdl/phish ESRI shape files, KMZ and GRIB2 formats will also be available for download from the above website. Users are encouraged to provide feedback on these experimental products by using the brief survey form available on line at: http://www.weather.gov/survey/nws-survey.php?code=phss Planning is underway to provide the Probabilistic Tropical Cyclone Inundation Guidance Products in GRIB2 format via the NWS Telecommunication Gateway in the future. If you have questions regarding this notice, please contact: John Kuhn National Weather Service Marine and Coastal Services Branch Silver Spring Maryland 20910 301-713-1677 X121 John.F.Kuhn@noaa.gov National Public Information Statements are online at: http://www.weather.gov/os/notif.htm $$