October 19, 2010

MEMORANDUM TO:  Record
FROM:           Dennis A. Keyser -- NP22
Subject:        Changes to IBM-CCS Data Preprocessor (PREPDATA)
                (September 9, 2004 Version -- UPDATE # 10)


The September 9, 2004 data preprocessor program (PREPDATA) was updated for the
tenth time.  UPDATE #10 was implemented on the IBM-CCS machines at 12Z on
October 19, 2010.  Except where noted, the changes below affect all eight
versions: NAM, NDAS, GFS, GDAS, RUC, CDAS, RTMA and AFOSPLT.

*************** I B M - C C S   U P D A T E   # 10 *************


I. OPERATIONAL CHANGES SPECIFIC TO A DATA TYPE

  A. CHANGES TO SURFACE LAND METAR DATA PROCESSING

     1) Stores the quality mark for reported altimeter setting in code figure 20
of category 8, but only if the METAR pressure quality mark was given a purge or
reject flag in the SDMEDIT file.  In this case, the altimeter quality mark is
set to the same value as the pressure quality mark from SDMEDIT  (either 12 or
14).  This will allow SDMEDIT rejected or purged pressure quality marks to be
honored when station pressure is calculated from altimeter setting (before it
was not honored resulting in purged or rejected surface pressure obs possibly
being assimilated).  If station pressure or sea-level pressure are missing, will
still store quality mark read in from SDMEDIT file from them.  [IW3UNPBF, MAIN,
SFCDTA]


  B. CHANGES TO SURFACE MESONET DATA PROCESSING

     1) Corrected bug which was not properly interpreting altimeter quality mark
in code figure 20 of category 8.  Many mesonet pressure quality marks were being
set to 2 or 15 when they should have been set to 3 or 13, respectively.
Mesonets do not report pressure, so the altimeter setting is used to calculate
pressure and the altimeter quality mark is transferred to pressure. [MAIN,
SFCDTA]


  C. CHANGES TO SURFACE MARINE DATA PROCESSING

     1)  Recognizes new, or soon-to-be new, unrestricted ship tank NC001013.
[IW3UNPBF]


  D. CHANGES TO SATELLITE-DERIVED WIND DATA PROCESSING

     1) Changes the first character of the report id from "?" (if so found) to
"R" for MTSAT-2 (satellite id  172) reports from JMA.  This is necessary so that
they will be properly recognized for historical reruns, etc. because from ~ 11
August to 30 September 2010, the dump processing code BUFR_DUPSAT incorrectly
placed "?" in the first character of these ids. [IW3UNPBF]

     2) Recognozes new AVHRR POES satellite-derived wind tank NC005080.
[IW3UNPBF]