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NOUS41 KWBC 191840

Service Change Notice 17-110
National Weather Service Headquarters Washington DC
240 PM EDT Thu Oct 19 2017

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

FROM:  Ben Kyger
  Director, NCEP Central Operations (NCO)

SUBJECT:  Update on Changes to Access, Planned Termination of
  Common Alerting Protocol version 1.1, and Operational
  Implementation of Common Alerting Protocol Version 1.2

Reference: NWS Service Change Notice (SCN) 17-35

SCN 17-35 announced the operational NWS implementation of
Watches/ Warnings/ Advisories (WWA) in Common Alerting Protocol
(CAP) version 1.2 (v1.2) format effective on April 30, 2017. The
notice identified a planned termination of CAP version 1.1
(v1.1) no sooner than September 1, 2017. Today`s notice updates
users that NWS termination of CAP v1.1 will be no sooner than
March 1, 2018, and reminds users of the dissemination channels
and detailed documentation for CAP v1.2.

NWS will continue providing CAP v1.1 until at least March 1,
2018 at

On or after March 1, 2018, NWS will permanently cease production
of CAP v1.1 in any form or on any NWS dissemination channel. A
future SCN will specify the exact effective date of these
service terminations. On the effective date, the documentation
for accessing CAP v1.2 and the 7 day archive of NWS CAP v1.2
messages currently located at

will be moved to

CAP v1.2 messages are provided through multiple dissemination
channels, including the NWS Application Programming Interface
(API), http and ftp file listings, and NOAAPORT satellite
broadcast as summarized in sections 1-3 below. More details are
provided on the above web page.

1) The NWS API endpoint at

provides access to CAP v1.2 messages, a digest of active CAP
v1.2 messages in Atomic Syndication Format (ATOM), and CAP
content in JavaScript Object Notation (JSON) format. Users of
the API have reported issues with the availability, timeliness,
and time stamps in the ATOM and JSON formatted outputs via the
API. These issues are being addressed and further updates to
these issues will be provided on the Change Log tab at

2) CAP v1.2 messages are available via http and ftp file
listings at

These file listings provide a traditional directory listing of
all CAP alerts issued for the past 7 days as well as directory
lists (ls-l and ls-lt) for CAP consumers wishing to frequently
check for any new CAP messages in the directory.

3) CAP v1.2 messages are available via NOAAPORT satellite
broadcast under the WMO Heading XOaa5i KWBC, where aa
corresponds to US, AK, CA, GM, HW, or ZS, and i is equal to 0
(zero) to 9.

As a reflection of continued improvements to NWS service
delivery, NWS CAP v1.2 messages may periodically undergo minor
changes or updates to the CAP elements or parameters. Since CAP
is eXtensible Markup Language (XML)-based, these minor changes
or updates should not impact the ability of NWS partners and
users to properly parse the CAP messages; however, partners and
users are encouraged to monitor the continuously updated Change
Log tab reference above for all changes or updates to the CAP
v1.2 elements and parameters that might impact use of NWS CAP or
provide additional value.

For any operational issues, including CAP access and
connectivity, contact:

Senior Duty Meteorologist
National Centers for Environmental Prediction (NCEP) Central

For other non-operational technical questions, contact:

Software Development Branch
NCEP Central Operations

For questions or suggestions about meteorological or hydrologic
content within CAP messages and CAP documentation, contact:

Mike Gerber
Office of Dissemination

National Service Change Notices are online at: is the U.S. government's official web portal to all federal, state and local government web resources and services.