February 20, 1996

MEMORANDUM TO:  Record
FROM:           Dennis A. Keyser -- W/NMC22
Subject:        Changes to OI/SSI-Data Preprocessor
                (July 12, 1995 Version -- UPDATE # 3)

The July 12, 1995 version of the data preprocessor program
(PREPDATA) was updated for the third time.  UPDATE #3 was
implemented on 1200 UTC 20 February 1996 on the CRAY (GLOBAL, ETA
versions).  All changes now affect only OBUFR = TRUE switch. 
Except where noted, the changes below affect both the GLOBAL and
ETA models.

*********************  U P D A T E   # 3  ***********************

 
I.  GENERAL CHANGES

     1) Namelist switches JSMASS and JSWIND now have more
possible values associated with them, other than only 0 or 9999
as before.  This allows certain combinations of satellite wind
producers/products and even certain GOES-EVEN and GOES-ODD
satellite numbers to be processed but flagged for non-use by the
analyses.

     2)  Program now recognizes that the suffix character of the
GOES satellite wind station id differs for every other odd ('A'
or 'C') or even (`B' or `D') satellite number.



II.  SPECIFIC OPERATIONAL CHANGES

   A. CHANGES TO ACARS AIRCRAFT PROCESSING 

     1) ETA: The namelist switch IACARL has been changed from
2296 to 0 in order to allow ACARS reports below 7500 feet to now
be passed on and used by the analyses.

  B. CHANGES TO UPPER-AIR DATA PROCESSING 

     1) ETA: The original tests used in the old REGIONAL PREPDA
for the processing of ON29 category 4 levels and for the
processing of ON29 category 3 winds on levels above the last non-
missing height and temperature level are again used for the
REGIONAL BUFR/PREPDA output.  This temporary fix will allow the
REGIONAL BUFR/PREPDA data to appear more like that in the old
REGIONAL PREPDA output.  The latter format is what is expected by
the ETA FERR and OI-analysis codes.