                     Model Change Bulletin
              
                            MCB#2                             02/10/93

                     WRPLOT (dated 93036)
             

     This Model Change Bulletin describes revisions to the WRPLOT
program (dated 93036).  The new version corrects a few problems with
the earlier version, and includes a new tabular output option.  The
following problems have been fixed:

     1.  The new version will correctly read user-generated *.DAT files
         which only include station ID, date, wind direction and wind
         speed (out to column 21).  The earlier version required placing
         a character in column 28.

     2.  A problem encountered with using multiple years of *.ZIP data
         for NWS stations available from SCRAM has been fixed.

     3.  A minor error with the way wind directions were randomized has
         been fixed.  This will result in very slight differences in
         frequency distributions generated for non-leap years.  However,
         these differences will probably not be noticeable on plots
         generated by the two versions.

In addition to these corrections, a new option has been added to create
a table of the frequency distributions.  This option is accessed from
the same menu as the other graph output options.  The tabular results
are displayed by WRPLOT, saved in an ASCII file, and can also be
printed from within the program.

     The WRPLOT program available from the SCRAM bulletin board
is a PC compatible version that generates wind rose statistics
and plots for selected meteorological stations for user-specified
date and time ranges.  Wind roses can be used to depict graphically
the dominant transport direction of the winds for an area.

     The WRPLOT program should not be confused with the WINDROSE
utility program also available on the SCRAM BBS.  WRPLOT was developed
primarily to produce graphic plots of wind rose statistics, whereas the
WINDROSE utility determines tables of wind frequency statistics but has
no graphics capability.

     This program will henceforth be identified by its name and
a julian date, i.e.: WRPLOT (dated 93036).  Future changes to this
program will be identified by an updated julian date found on the
first line of the model source code and followed by a reference
to a SCRAM BBS Model Change Bulletin (MCB#n) which will explain
the nature and contents of the changes.  All Model Change
Bulletins for this program will always be available for back
reference on this BBS. In the future, notification of changes
(MCBs) to this model will be made in the SCRAM ALERTS section
of this BBS immediately following the LOGON procedure.

                       ******************
                       * Important Note *  
                       ******************
   
     New Model Change Bulletins will ONLY be issued when there
is a change to the source code for this program. Changes to test
cases and/or any pre and post processors that are included in the
archived file for this program will be addressed and
appropriately identified in an amendment to the program's latest
MCB with notification posted in the SCRAM ALERTS section of the
BBS. 

NOTE:  Current users of the WRPLOT program need ONLY download the WRPLOTE.ZIP
       file, which contains a new executable file named WRPLOT.EXE.  This
       should replace the previous WRPLOT.EXE.  This option is given due to
       the large size of the WRPLOT.ZIP (1MB) vs. the size of WRPLOTE.EXE
       (27K).  Download time for WRPLOTE.ZIP is significantly less than for
       the entire WRPLOT.ZIP file.

       New users should download the full set of files located in the
       WRPLOT.ZIP file.
                       
     Questions or comments on the WRPLOT program should be directed
to Dennis Atkinson, EPA-OAQPS, (919) 541-0518.

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