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NOUS41 KWBC 081425
PNSWSH
TECHNICAL IMPLEMENTATION NOTICE 08-09
NATIONAL WEATHER SERVICE HEADQUARTERS WASHINGTON DC
925 AM EST FRI FEB 8 2008
TO: SUBSCRIBERS:
-FAMILY OF SERVICES
-NOAA WEATHER WIRE SERVICE
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK
OTHER NWS PARTNERS...USERS AND EMPLOYEES
FROM: FIONA M. HORSFALL
ACTING CHIEF...CLIMATE SERVICES DIVISION
SUBJECT: NOAA UPDATES ITS LONG-TERM STATION EXTREMES OF DAILY
TEMPERATURE AND PRECIPITATION FOR DATA THROUGH 2007:
EFFECTIVE DECEMBER 31 2007
EFFECTIVE DECEMBER 31 2007 LONG-TERM STATION EXTREMES OF DAILY
TEMPERATURE AND PRECIPITATION FOR APROXIMATELY 268 KEY U.S.
WEATHER STATIONS WERE UPDATED FOR DATA THROUGH 2007. TO PROVIDE
THE LONGEST POSSIBLE PERIOD OF RECORD AT EACH STATION TO
DETERMINE EXTREMES...A PROJECT CALLED THREADEX /FOR THREADED
EXTREMES/ PIECES OR THREADS STATION DATA TOGETHER TO FORM A
SINGLE...LONG-TERM SET OF DAILY DATA. THE THREADEX PROJECT IS
OUTLINED AT: /USE LOWER CASE/
HTTP://THREADEX.RCC-ACIS.ORG/
NOAA HAS BUILT THREADS FOR THE APROXIMATELY 268 LOCATIONS THAT
ARE PUBLISHED IN THE NCDC LOCAL CLIMATOLOGICAL DATA /LCD/. THE
EXTREMES DERIVED FROM THE THREADS ARE USED IN THE NWS DAILY
CLIMATE REPORTS /CLI/.
THREADEX ADDRESSES THE ISSUE OF FRAGMENTED WEATHER DATA OVER
TIME DUE TO STATION RELOCATIONS...WHICH HAVE HISTORICALLY
INCLUDED INSTRUMENTATION MOVES FROM CITY LOCATIONS TO AIRPORTS
...AND MOVES AT AIRPORTS DUE TO EXPANSIONS. OBTAINING A LONG
TIME SERIES /I.E...100 YEARS OR MORE/ IS DIFFICULT UNLESS
RECORDS FROM THE VARIOUS LOCATIONS ARE THREADED TOGETHER.
THREADING A STATION RECORD INVOLVES A NUMBER OF STEPS. THE
RECORD OF A CURRENTLY ACTIVE STATION IS USED AS THE STARTING
POINT FOR A STATION THREAD. THIS STATION/S CURRENT RECORD IS
USED AS FAR BACK IN TIME AS POSSIBLE. OTHER LOCAL WEATHER
STATIONS NEARBY ARE THEN IDENTIFIED TO EXTEND THE THREAD FURTHER
BACK IN TIME... WITH PREFERENCE GIVEN TO NATIONAL WEATHER
SERVICE/WEATHER BUREAU STATIONS. THE THREAD IS EXTENDED BACK IN
TIME AS FAR AS POSSIBLE USING NOAA DAILY DATA AVAILABLE IN
DIGITAL FORM. INPUT FROM PARTNERS AND NWS WEATHER FORECAST
OFFICES WAS THEN SOLICITED AND THIS LOCAL EXPERTISE WAS USED TO
FINE-TUNE THE STATION THREADS.
THREADEX IS A COLLABORATIVE EFFORT BETWEEN NWS...NOAA/S NATIONAL
CLIMATIC DATA CENTER...THE NORTHEAST REGIONAL CLIMATE
CENTER...AND STATE CLIMATOLOGISTS.
FOR QUESTIONS REGARDING THE THREADEX PROJECT...CONTACT
MICHAEL J. BREWER
NWS/OS4
1325 EAST WEST HWY
SILVER SPRING MD 20910-3283
PHONE: 301-713-1970 EXT 123
NWS TECHNICAL IMPLEMENTATION NOTICES ARE ONLINE AT:
/USE LOWER CASE/
HTTP://WWW.NWS.NOAA/GOV/OM/NOTIF.HTM
$$