792
NOUS41 KWBC 191450
PNSWSH
SERVICE CHANGE NOTICE 25-96
NATIONAL WEATHER SERVICE HEADQUARTERS SILVER SPRING MD
950 AM EST FRI DEC 19 2025
TO: SUBSCRIBERS:
-NOAA WEATHER WIRE SERVICE
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
-NOAAPORT
NOAA WEATHER RADIO ALL HAZARDS LISTENERS
EAS PARTICIPANTS
OTHER NWS PARTNERS, USERS AND EMPLOYEES
FROM: MARY MULLUSKY, CHIEF
OPERATIONS SERVICES DIVISION
SUBJECT: IMPLEMENTATION OF PARTIAL COUNTY ALERTING VIA NOAA
WEATHER RADIO ALL HAZARDS (NWR) AND THE EMERGENCY ALERT SYSTEM
(EAS)FOR ARAPAHOE COUNTY, COLORADO EFFECTIVE ON MARCH 3, 2026
EFFECTIVE ON TUE, MARCH 3, 2026,AT 2:00 PM MOUNTAIN STANDARD
TIME (MST), 2100 COORDINATED UNIVERSAL TIME (UTC), NWS
DENVER/BOULDER (BOU) WILL IMPLEMENT PARTIAL COUNTY ALERTING
(PCA) FOR ARAPAHOE COUNTY, COLORADO. THIS IS BASED ON POSITIVE
FEEDBACK FROM THE BROADCAST COMMUNITY, LOCAL OFFICIALS AND THE
PUBLIC.
IF MARCH 3, 2026 IS DECLARED A CRITICAL WEATHER DAY, THIS
IMPLEMENTATION WILL BE POSTPONED TO MARCH 4, 2026 AT 2100 UTC.
THE FOLLOWING WEATHER WARNINGS FROM WFO BOU ARE IMPACTED FOR
THIS PCA IMPLEMENTATION:
PRODUCT NAME WMO HEADING AWIPS ID
------------ ----------- --------
DUST STORM WARNING WWUS55 KBOU DSWBOU
FLASH FLOOD WARNING WGUS55 KBOU FFWBOU
SEVERE THUNDERSTORM WARNING WUUS55 KBOU SVRBOU
SNOW SQUALL WARNING WWUS55 KBOU SQWBOU
TORNADO WARNING WFUS55 KBOU TORBOU
NWS DISSEMINATES WEATHER WARNINGS VIA NWR AND THE EAS. WHILE
MANY NWS WARNINGS HAVE BECOME MORE REFINED IN AREAL EXTENT USING
FORECASTER-DEFINED POLYGONS, THESE WARNINGS ARE GENERALLY
CONVEYED VIA NWR AND EAS ON A WHOLE (ENTIRE) COUNTY BASIS.
HOWEVER, NWS HAS THE CAPABILITY TO DISSEMINATE THESE WARNINGS
VIA NWR AND EAS FOR SMALLER AREAL SECTIONS OF COUNTIES. NWS
REFERS TO THESE AREAS AS COUNTY PARTITIONS; THE FEDERAL
COMMUNICATIONS COMMISSION (FCC) REFERS TO THEM AS SUBDIVISIONS.
DISSEMINATING WARNINGS THROUGH NWR AND EAS USING PARTITIONS IS
REFERRED TO AS PCA.
PCA REDUCES THE GEOGRAPHICAL OVER-ALERTING OF WARNINGS BY MORE
CLOSELY ASSOCIATING POLYGON-DEFINED WARNINGS AND POLYGON-DEFINED
NWEMS WITH COUNTY PARTITIONS. WITH PCA, NWR SPECIFIC AREA
MESSAGE ENCODING (SAME)-EQUIPPED USERS MAY SELECT THE COUNTY
PARTITION(S) FOR WHICH THEY WILL RECEIVE AUTOMATED ALERTS.
SIMILARLY, PCA ALLOWS BROADCASTERS TO SELECT THE COUNTY
PARTITION(S) THEY WILL CONVEY NWS WARNINGS THROUGH THE EAS. PCA
IMPLEMENTATION MAY HELP LIMIT AND BETTER TARGET EAS ACTIVATION
IN A GIVEN MEDIA MARKET.
WFO BOULDER HAS CONFERRED WITH LOCAL EMERGENCY MANAGERS, STATE
AND LOCAL GOVERNMENT OFFICIALS AND BROADCASTERS SERVING ARAPAHOE
COUNTY AND WILL IMPLEMENT 3 PARTIAL COUNTY ZONES FOR ARAPAHOE
COUNTY. A COMPREHENSIVE DESCRIPTION WITH MAPS AND THE NEW SAME
AND EAS LOCATION CODES ASSOCIATED WITH EACH ARAPAHOE COUNTY
PARTIAL COUNTY ZONE IS PROVIDED ONLINE AT:
HTTPS://WWW.WEATHER.GOV/BOU/ARAPAHOECNTYEASCHANGE
THE SHAPEFILES WITH THE ARAPAHOE COUNTY PARTIAL COUNTY
BOUNDARIES FOR NWR AND EAS ARE POSTED ONLINE AT:
HTTPS://WWW.WEATHER.GOV/GIS/AWIPSSHAPEFILES
INSTRUCTIONS FOR PROGRAMMING YOUR SAME-EQUIPPED NWR RECEIVER
WITH THE NEW PARTIAL COUNTY SAME LOCATION CODES ARE ONLINE AT:
HTTPS://WWW.WEATHER.GOV/PCA/NWR
ONCE ESTABLISHED IN OPERATIONS, THE BOUNDARIES OF THE ARAPAHOE
COUNTY PARTITIONS ARE FIXED, UNLESS MODIFIED AT A LATER DATE
THROUGH A FORMAL CHANGE PROCESS.
A COMPREHENSIVE DESCRIPTION OF PCA AND THE EXPANSION OF PCA TO
SELECT US COUNTIES IS ONLINE AT:
HTTPS://WWW.WEATHER.GOV/PCA
WFO BOULDER ANTICIPATES THAT ADDITIONAL NWS WARNINGS WILL USE
PCA IN THE FUTURE. ANY SERVICE ENHANCEMENTS WILL BE PRECEDED BY
A FUTURE SERVICE CHANGE NOTICE.
FOR QUESTIONS OR CONCERNS ON THE PCA IMPLEMENTATION FOR ARAPAHOE
COUNTY, PLEASE CONTACT:
GREG HEAVENER
WARNING COORDINATION METEOROLOGIST
WFO DENVER/BOULDER
BOULDER, CO
TELEPHONE: 303-494-3210 X 726
EMAIL: GREG.HEAVENER@NOAA.GOV
FOR COMMENTS OR QUESTIONS ON THE NATIONAL LEVEL PCA INITIATIVE,
PLEASE CONTACT:
BRIAN MIRETZKY
METEOROLOGIST, NWS DISSEMINATION SERVICES
NWS HEADQUARTERS
SILVER SPRING, MD
301-427-9315
BRIAN.MIRETZKY@NOAA.GOV
NATIONAL SERVICE CHANGE NOTICES ARE ONLINE AT:
HTTPS://WWW.WEATHER.GOV/NOTIFICATION
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