NOUS41 KWBC 051643



Service Change Notice 12-25

National Weather Service Headquarters Washington DC

1243 PM EDT Thu Jul 5 2012


To:      Subscribers:

         -Family of Services

         -NOAA Weather Wire Service

         -Emergency Managers Weather Information Network


         Other NWS Partners and NWS Employees


 From:   Thomas Graziano

         Chief, Hydrologic Services Division

         National Weather Service Headquarters               


Subject: NWS to Establish New Methods to Collect Automated Flood

         Warning System Information by March 31, 2013


For over 30 years, the NWS has routinely collected raw Automated Local

Evaluation in Real Time (ALERT) messages.  NWS field offices make use

of these ALERT messages to support hydrologic forecast and warning

operations.  The NWS Automated Flood Warning System (AFWS) currently

collects and processes raw ALERT messages 24x7x365 from over 1700

rainfall and stream sensors in 12 states: Connecticut, Kentucky,

Maryland, North Carolina, New Jersey, New York, Ohio, Pennsylvania,

South Carolina, Tennessee, Virginia, and West Virginia.  These data

are used routinely to generate NWS river forecasts and flood

advisories, watches, and warnings. 


By March 31, 2013, to ensure ALERT data continue to be available for

forecast and warning operations, the NWS is engaging data partners and

requesting they provide ALERT messages to the NWS in a Standard

Hydrologic Exchange Format (SHEF).  


SHEF is a well-established and well-documented standard for data

exchange.  This request will increase the efficiency and extensibility

of the NWS AFWS and enable better integration of ALERT data into the

Advanced Hydrologic Prediction Service (AHPS) web portal.  The NWS

will work with data partners to effect a transition to this new AFWS

operational workflow. After March 31, 2013, NWS will no longer be able

to ingest raw ALERT messages. 


The NWS is requesting SHEF encoded ALERT messages from these 12 states

be sent to a central NWS server within the Office of Hydrologic

Development. The ALERT messages will then be encoded within OHD’s

Hydrometeorological Automated Data System and disseminated over the

Satellite Broadcast Network to assure the continued availability and

use by the NWS field offices in the watch, warning, and advisory

mission.  Additionally, the NWS will update our AHPS Web pages to

include the timely display of data from these AFWS rain and stream

sites. These AFWS data will be managed, integrated and displayed by

the NWS in the same manner as data for AHPS sites.


Detailed information on SHEF is available at:


The AHPS Web page portal is found at:


For questions or to access more information about the new methods to

collect AFWS data, please contact:


John Bradley

National Automated Flood Warning System Coordinator

National Weather Service Headquarters

301-713-0624 x154


National Service Change Notices are online at: