NOUS41 KWBC 291545



Service Change Notice 16-35

National Ocean Service Office of Coast Survey Silver Spring MD

Relayed by the National Weather Service

1145 AM EDT Thu Sep 29, 2016


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS and NOS Partners and NOAA Employees


From:     Edward Myers

          Chief, Coastal Marine Modeling Branch

          Coast Survey Development Laboratory

          NOS/Office of Coast Survey


Subject:  Amended: Addition of a map service to NOAA's nowCOAST(tm) to

          provide access to NWS/National Hurricane Center's

          Potential Storm Surge Flooding Map Effective

          Wednesday, September 28, 2016


Amended to change date from Oct. 5 to Sept. 28, 2016 due to possible Critical Weather Day next week


As of 3 PM EDT Wednesday, September 28, 2016, the NOAA nowCOAST(tm)

( provides access to the NWS/National Hurricane Center

Potential Storm Surge Flooding Map via web mapping services. Users can access the Potential Storm

Surge Flooding Map using two different protocols: ArcGIS Representational State Transfer (REST)

Map Service and OGC Web Map Service (WMS).  This service will allow NOAA users to integrate

this map with their own map layers such as coastal evacuation routes and critical infrastructure

on client- or server-based Geographic Information Systems or other mapping applications. In addition,

users will also be able to view the NHC map via the nowCOAST map viewer.


The Potential Storm Surge Flooding Map was developed by the NHC over the

course of several years in consultation with social scientists, emergency

managers, broadcast meteorologists, and others. The map is intended to depict the risk

associated with coastal flooding from storm surge associated with tropical cyclones. 

On June 1, 2016 it became an operational product, issued on demand for certain tropical

cyclones that are expected to affect the Atlantic or Gulf Coasts of the United States.


The nowCOAST map service will provide access to the latest official NWS

Potential Storm Surge Flooding Map which depicts the geographical areas where inundation

from storm surge could occur along with the heights, above ground, that water could reach

in those areas. These potential heights are represented with different colors based on water level:


Greater than 1 foot above ground (blue)

Greater than 3 feet above ground (yellow)

Greater than 6 feet above ground (orange)

Greater than 9 feet above ground (red) 


Two versions of this graphic are provided in this map--one with a mask

(depicted in gray) identifying Intertidal Zone/Estuarine Wetland areas and another version

without the Intertidal Zone/Estuarine Wetland mask.  Two additional layers are provided

to depict first, the full geographic extent for which the map is presently valid

(the "map boundary"), and second, Levee Areas, if any, within the affected area

(symbolized with a black-and-white diagonal hatch pattern). If the map is not presently active,

all layers will be blank except for the Map Boundary layer, which will display a gray shaded

region indicating the coverage area for any potential future graphics along with a text label

indicating that the map is not presently available.


The nowCOAST map service will be updated approximately every  10 minutes to ensure the latest

information is provided to the user as soon as it becomes available. Once issued, the Potential

Storm Surge Flooding Map will be updated by NHC every 6 hours alongside each new NHC Forecast

Advisory for the associated tropical cyclone. Due to processing requirements, however,

during the creation of this product, the map will be available approximately 60 to 90 minutes

following the release of the associated Forecast Advisory, at which point nowCOAST will acquire

it and update this map service within the next 10 to  20 minutes (i.e., this product will be

updated on nowCOAST within approximately 70 to 110 minutes after the associated forecast advisory

is released).


This new nowCOAST map service can be found at


Additional information about NHC’s Potential Storm Surge

Flooding Map can be found at


nowCOAST provides coastal intelligence on present and future

environmental conditions for coastal and maritime users by

integrating data and information from across NOAA and other

federal and state agencies.  nowCOAST was developed by NOS’

Coast Survey Development Laboratory, and is hosted on NOAA’s

Integrated Dissemination Program (IDP) infrastructure where it

is monitored 24 x 7 by NWS/NCEP Central Operations.


For questions concerning this new map service, please contact:


John G.W. Kelley

NOS Co-Project Manager


Silver Spring, MD



Nipa Parikh

NWS Co-Project Manager


Silver Spring, MD



For questions concerning the NHC Potential Storm Surge Flooding

Map, please contact:


Jamie Rhome

Storm Surge Specialist and Team Lead

NWS/NCEP/NHC Storm Surge Unit

Miami, FL



For information about NOAA/IDP, please contact:


Michelle M. Mainelli

NOAA Integrated Dissemination Program Manager

NWS Office of Dissemination

Silver Spring, MD



National Service Change Notices are online at: