Public Information Statement
Issued by NWS National HQ

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000
NOUS41 KWBC 171905
PNSWSH

Service Change Notice 17-16
National Weather Service Headquarters Silver Spring MD
305 PM EST Fri Feb 17 2017

To:   Subscribers:
   -NOAA Weather Wire Service
   -Emergency Managers Weather Information Network
   -NOAAPORT
   Other NWS Partners and NWS Employees

From:   Allison Allen
   Chief, Marine, Tropical and Tsunami Services Branch

Subject:   Addition of Tropical Cyclone Storm Surge Watches
   and Warnings for the Atlantic and Gulf Coasts of
   the Contiguous United States effective on or around
   June 1, 2017

Reference PNS16-21 Amended:

http://www.nws.noaa.gov/om/notification/pns16-
21tcvhlschangesforsswwaaa.htm

Effective on or around June 1, 2017, NWS will implement new
Storm Surge Watches and Warnings in association with Atlantic
basin tropical cyclones (i.e., hurricanes, tropical storms and
tropical depressions), subtropical cyclones or post-tropical
cyclones affecting the contiguous United States. The new Storm
Surge Watch/Warning will be integrated into the current NWS
product suite, including all applicable tropical cyclone
graphical and textual advisory products. Definitions for the
Storm Surge Watch and Warning are provided below:

Storm Surge Watch: The possibility of life-threatening
inundation from rising water moving inland from the shoreline
somewhere within the specified area, generally within 48 hours,
in association with a tropical cyclone, a subtropical cyclone or
a post-tropical cyclone.  The watch may be issued earlier when
other conditions, such as the onset of tropical-storm-force
winds, are expected to limit the time available to take
protective actions for surge (e.g., evacuations). The watch may
also be issued for locations not expected to receive life-
threatening inundation but which could potentially be isolated
by inundation in adjacent areas.

Storm Surge Warning:  The danger of life-threatening inundation
from rising water moving inland from the shoreline somewhere
within the specified area, generally within 36 hours, in
association with a tropical cyclone, a subtropical cyclone or a
post-tropical cyclone. The warning may be issued earlier when
other conditions, such as the onset of tropical-storm-force
winds, are expected to limit the time available to take
protective actions for surge (e.g., evacuations).  The warning
may also be issued for locations not expected to receive life-
threatening inundation, but which could potentially be isolated
by inundation in adjacent areas.

Storm Surge Watches or Warnings will not be issued for the
Pacific hurricane basin or Weather Forecast Office (WFO) San
Juan`s area of responsibility at this time.

NWS will continue to issue Coastal Flood Watches, Warnings, and
Advisories for flooding of coastal areas associated with storms
that are not tropical cyclones, subtropical cyclones, or post-
tropical cyclones. Most frequently, they will be issued for
winter storms, unusually high tides, or prolonged periods of
strong onshore winds that have pushed water into places it does
not normally go. NWS may issue Coastal Flood Advisories in areas
adjacent to Tropical Cyclone Wind or Storm Surge Watches or
Warnings to alert for potentially dangerous coastal flooding
that is below the threshold established by the NWS for life-
threatening inundation.

Changes to the Hurricane Local Statement (HLS) product to
reflect Storm Surge Watches or Warnings issued by WFOs will be
limited to the "NEW INFORMATION" section of the product.  The
subsections for "CHANGES TO THE WATCHES AND WARNINGS" and
"CURRENT WATCHES AND WARNINGS" will include Storm Surge Watches
or Warnings when condition warrant.

National Hurricane Center (NHC) Tropical Cyclone Public Advisory
(TCP) products will now list Storm Surge Watches and Warnings,
as applicable, under the "WATCHES AND WARNINGS" section. More
detailed information about the storm surge hazard will be
provided in the "HAZARDS AFFECTING LAND" section.  Storm Surge
Watches and Warnings will be listed in the "SUMMARY OF WATCHES
AND WARNINGS IN EFFECT" section of the Tropical Cyclone
Forecast/Advisory (TCM) product.

In addition, the Storm Surge Watch/Warning graphic previously
issued by NHC as a prototype will become operational at the
start of the 2017 Atlantic hurricane season.  Because Storm
Surge Watches and Warnings are issued on a grid rather than for
entire NWS zones or for entire counties, users are highly
encouraged to use the Keyhole Markup Language (KML) files
available on the NHC website, rather than the Valid Time Event
Code (VTEC), to obtain the most timely and accurate depiction
of the area under a Storm Surge Watch or Warning. This
information is also available in the NWS National Digital
Forecast Database (NDFD).

All Tropical Cyclone Watch/Warning (TCV) products issued by NHC
and WFOs for tropical cyclones, subtropical cyclone and post-
tropical cyclones affecting the Atlantic and Gulf coasts of the
contiguous United States will include VTEC for Storm Surge
Watches and/or Warnings when conditions warrant.  The following
VTEC phenomenon and significance codes will be used:

    SS.A - Storm Surge Watch
    SS.W - Storm Surge Warning

Examples of the WFO and NHC issued TCV products with the new
Storm Surge Watches and Warnings can be viewed at:

www.nhc.noaa.gov/experimental/tcv

VTEC will continue to be used to activate some dissemination
systems, such as NOAA Weather Radio All-Hazards (NWR). While
users are highly encouraged to use the KML files to display
Storm Surge Watches and Warnings, the NWS recognizes many users
rely on VTEC to parse and disseminate information. VTEC users
should be aware the geographical area associated with a Storm
Surge Watch or Warning using VTEC will be larger than the actual
area of the gridded-based watch or warning as seen in the Storm
Surge Watch/Warning Graphic KML file or the NDFD.

Common Alerting Protocol (CAP) formatted WFO TCV products will
be produced and available through a number of dissemination
sources including the NWS website and NOAAport under the header
XOUS5x. The CAP messages will be used to activate Wireless
Emergency Alerts (WEA) and to populate NWS WFO
watch/warning/advisory maps and point forecast pages. Users of
these products and direct users of the CAP messages should be
aware that the geographical area associated with a Storm Surge
Watch or Warning using CAP will be larger than the actual grid-
based area of the watch or warning as depicted by the NDFD grids
or KML file. The CAP-associated geographical watch/warning areas
will, however, more closely match the true gridded watch/warning
than the areas identified by VTEC, as the CAP-associated areas
will be limited to the portions of zones known to be susceptible
to tropical cyclone storm surge flooding.

Beginning in the 2017 hurricane season, the NWS may request
Emergency Alert System (EAS) and WEA activation for the Storm
Surge Warning. In most jurisdictions, the NWS will not request
EAS or WEA activation for the Storm Surge Watch. Specific
details about changes to the EAS for your area will be provided
by your local WFO in Public Information Statements, on WFO web
pages, and over NWR. Broadcasters should note that if EAS
equipment is not updated and the WFO requests EAS activation
with the new event code(s), EAS encoder/decoder equipment will
usually decode the information received as an "UNKNOWN"
event code.

Storm Surge Watches and Warnings will be broadcast over NWR.
Current NWR receivers providing a limited, caption-like message
display will likely show wording such as "UNKNOWN WATCH" or
"UNKNOWN WARNING."  Receivers equipped with Special Area Message
Encoding (SAME) capability, and properly programmed, should
automatically turn on for counties affected by a Storm Surge
Watch or Warning. The 1050-Hz Warning Alarm Tone (WAT) will
generally be used for the Storm Surge Warning but will not be
used for the Storm Surge Watch.

The NWS is seeking comments now through March 4, 2017, on
changing the criteria for issuing tropical cyclone watches and
warnings to include certain land-threatening disturbances that
are not yet tropical cyclones. If this change is adopted, the
NWS would have the option to issue Storm Surge Watches and
Warnings for such disturbances. Please see NWS Public
Information Statement 17-04 linked below for more details:

http://www.nws.noaa.gov/om/notification/pns17-
04potential_cyclones.htm

For more information, please contact:
Jessica Schauer
NWS Marine, Tropical and Tsunami Services Branch
Miami, FL 33165
Telephone: 305-229-4476
Email: jessica.schauer@noaa.gov
or
Wayne Presnell
NWS Marine, Tropical and Tsunami Services Branch
Silver Spring, MD 20910
Telephone: 301-427-9390
Email: wayne.presnell@noaa.gov

National Public Information Statements are online at:

http://www.weather.gov/os/notif.htm



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