794
NOUS41 KWBC 012105
PNSWSH
PUBLIC INFORMATION STATEMENT 24-64
NATIONAL WEATHER SERVICE HEADQUARTERS SILVER SPRING MD
505 PM EDT TUE SEP 1 2026
TO: SUBSCRIBERS:
-NOAA WEATHER WIRE SERVICE
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
-NOAAPORT
OTHER NWS PARTNERS, USERS AND EMPLOYEES
FROM: DAVID NOVAK, PH.D,
DIRECTOR, NCEP WEATHER PREDICTION CENTER
SUBJECT: SOLICITING COMMENTS THROUGH OCTOBER 1, 2026 ON THE
PROPOSAL TO TRANSITION THE WEATHER PREDICTION CENTER SUPER
ENSEMBLE PROBABILISTIC WINTER AND QUANTITATIVE PRECIPITATION
FORECAST DATA TO THE PROBABILISTIC PRECIPITATION PORTAL DATA
THROUGH OCTOBER 1, 2026, THE NATIONAL WEATHER SERVICE (NWS) IS
SOLICITING COMMENTS TO ASSESS THE PROPOSED TRANSITION OF THE
WEATHER PREDICTION CENTER (WPC) SUPER ENSEMBLE (WSE)
PROBABILISTIC WINTER PRECIPITATION FORECAST (PWPF) DATA AND
PROBABILISTIC QUANTITATIVE PRECIPITATION FORECAST (PQPF) DATA TO
THE PROBABILISTIC PRECIPITATION PORTAL (PPP), WHICH IS SCHEDULED
FOR OPERATIONAL IMPLEMENTATION ON OR ABOUT OCTOBER 1, 2026. THE
LEGACY PWPF AND PQPF WEBPAGE WILL BE DISCONTINUED AT THE SAME
TIME.
THE PPP WEBSITE CAN BE VIEWED HERE:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/PROB_PRECIP/
PWPF AND PQPF DATA THAT IS CURRENTLY AVAILABLE ON THE SATELLITE
BROADCAST NETWORK (SBN), IS DERIVED FROM THE WSE, WHEREAS THE
PWPF AND PQPF DATA ON THE PPP IS DERIVED FROM THE NATIONAL BLEND
OF MODELS (NBM) AND ADJUSTED BY OPERATIONAL FORECASTERS. DATA
FROM THE PPP WILL MATCH THE EXISTING PWPF AND PQPF IN FILE
FORMAT AND TIMEFRAME EXTENT. THIS INCLUDES BOTH THE EXCEEDANCE
PROBABILITIES FOR SPECIFIC AMOUNTS OF SNOW, ICE, AND QPF, AS
WELL AS THE PERCENTILE DATA. THE STANDARD DEVIATION INFORMATION
WILL NO LONGER BE CREATED DUE TO FUNDAMENTAL DIFFERENCES IN HOW
THESE PROBABILITIES ARE CALCULATED IN THE PPP WHEN COMPARED TO
THE WSE.
THE PPP PROBABILISTIC DATA WILL BE AVAILABLE IN GRIB2 FORMAT ON
A PUBLIC-FACING FILE TRANSFER PROTOCOL (FTP) WEBSITE THAT WILL
BE AVAILABLE WHEN THE PPP BECOMES OPERATIONAL.IT WILL ALSO BE
AVAILABLE FOR DOWNLOAD IN KML AND SHAPEFILE FORMAT AT THE 24-,
36-, 48-, AND 72-HOUR PERIODS OUT TO 72 HOURS.THE PPP-DERIVED
DATA WILL NOT BE AVAILABLE ON THE SBN, AND THE WSE-DERIVED DATA
WILL CEASE FLOWING OVER THE SBN.
PROBABILISTIC SNOW AND ICE PRODUCTS THAT WILL BE AFFECTED BY
THIS CHANGE AND THEIR ASSOCIATED WMO HEADERS ARE LISTED IN THIS
SHEET:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/PWPF/WPC_PWPF_WMO_HEADERS.PDF
PROBABILISTIC QPF PRODUCTS THAT WILL BE AFFECTED BY THIS CHANGE
AND THEIR ASSOCIATED WMO HEADERS ARE LISTED IN THIS SHEET:
HTTPS://WWW.WEATHER.GOV/MEDIA/NOTIFICATION/REF/PQPF_WMO_HEADERS.
THE FOLLOWING PWPF REDBOOK GRAPHIC PRODUCTS WILL BE TERMINATED
BY THIS CHANGE IN FAVOR OF CUSTOMIZABLE GRAPHICS THAT CAN BE
CREATED BY THE USER ON THE PPP WEBSITE:
PRODUCT NAME WMO HEADING AWIPS ID
----------------- ----------- --------
DAY 1 PROBABILITY OF SNOW >4 PSBB04 KWNH NMCGPHB4S
DAY 1 PROBABILITY OF SNOW >8 PSBB08 KWNH NMCGPHB8S
DAY 1 PROBABILITY OF SNOW >12 PSBB12 KWNH NMCGPHB2S
DAY 1 PROBABILITY OF ICE >0.25 PSBB25 KWNH NMCGPHB5Z
DAY 2 PROBABILITY OF SNOW >4 PSBC04 KWNH NMCGPHC4S
DAY 2 PROBABILITY OF SNOW >8 PSBC08 KWNH NMCGPHC8S
DAY 2 PROBABILITY OF SNOW >12 PSBC12 KWNH NMCGPHC2S
DAY 2 PROBABILITY OF ICE >0.25 PSBC25 KWNH NMCGPHC5Z
DAY 3 PROBABILITY OF SNOW >4 PSBD04 KWNH NMCGPHD4S
DAY 3 PROBABILITY OF SNOW >8 PSBD08 KWNH NMCGPHD8S
DAY 3 PROBABILITY OF SNOW >12 PSBD12 KWNH NMCGPHD2S
DAY 3 PROBABILITY OF ICE >0.25 PSBD25 KWNH NMCGPHD5Z
THE CURRENT PWPF DATA CAN BE VIEWED AT THIS WEBSITE:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/PWPF/WWD_ACCUM_PROBS.PHP
THE CURRENT PQPF DATA CAN BE VIEWED AT THIS WEBSITE:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/PQPF/CONUS_HPC_PQPF.PHP
THESE TWO WEBSITES WILL BE RETIRED IN FAVOR OF THE PPP WEBSITE.
A DESCRIPTION OF THE CURRENT PWPF PRODUCTS CAN BE FOUND IN THE
NATIONAL WINTER WEATHER PRODUCTS SPECIFICATION NWSI 10-514
DIRECTIVE HERE:
HTTPS://WWW.WEATHER.GOV/MEDIA/DIRECTIVES/010_PDFS/PD01005014CURR
A DESCRIPTION OF THE CURRENT PQPF PRODUCTS CAN BE FOUND IN THE
PQPF PRODUCT DESCRIPTION DOCUMENT HERE:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/PQPF/PDD_WPC_PQPF.PDF
A DESCRIPTION OF THE PPP CAN BE FOUND IN THE PPP SERVICE
DESCRIPTION DOCUMENT HERE:
HTTPS://NSDESK.SERVICENOWSERVICES.COM/API/G_NOA/NWSPC/RES2/CD79B
82D1B4072500D690F67624BCB15
COMMENTS ON THE PROPOSAL TO TRANSITION THE WPC WSE-BASED
PROBABILISTIC PWPF AND PQPF DATA THE NBM-BASED PPP DATA CAN BE
ADDRESSED TO:
WPC SERVICES
WEATHER PREDICTION CENTER
RIVERDALE PARK, MD
WPCSERVICES@NOAA.GOV
NATIONAL PUBLIC INFORMATION STATEMENTS ARE ONLINE AT:
HTTPS://WWW.WEATHER.GOV/NOTIFICATION/
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