NOUS41 KWBC 171226
Public Information Statement
National Weather Service Headquarters Washington DC
830 AM EDT Tue Apr 17 2012
To:      Subscribers:
         -Family of Services
         -NOAA Weather Wire Service
         -Emergency Managers Weather Information Network
         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:
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:
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
National Public Information Statements are online at: