Look into using pcp_combine, a tool that comes with the MET package that includes MODE. (<a href="http://www.dtcenter.org/met/users/support/online_tutorial/METv2.0/pcp_combine/index.php">http://www.dtcenter.org/met/users/support/online_tutorial/METv2.0/pcp_combine/index.php</a>) I use it to change the run-total accumulated precip in my WRF runs into 1-hr accumulated precip using the argument pcp_combine -subtract (WRF file 1) (hour of the run) (WRF file 2) (hour of the run) (name of output file)<br>
<br>Jeff Duda<br><br><div class="gmail_quote">On Thu, Feb 11, 2010 at 10:43 AM, Chris Hayes <span dir="ltr"><<a href="mailto:c.hayes@weeronline.nl">c.hayes@weeronline.nl</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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<p class="MsoNormal"><span lang="EN-US">Dear group</span></p>
<p class="MsoNormal"><span lang="EN-US">I would like to use grib files (grib 1) to create
new grib (grib 1) files, with hourly change values instead of accumulated
values.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">E.g. grib_03:00 contains
accumulative_precipitation value 12</span></p>
<p class="MsoNormal"><span lang="EN-US">And grib_04:00 contains accumulative_precipitation
value 15</span></p>
<p class="MsoNormal"><span lang="EN-US">Then I would like to create a new grib file
with hourly_precipitation value 3 (15-12).</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">The reason I do not just open them both
and do the math to create a map (I asked that question earlier) is that we
would like to use the new grib file for other purposes as well.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">An example of this would be very helpful.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">Sincerely,</span></p>
<p class="MsoNormal"><span lang="EN-US">Chris</span></p>
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</blockquote></div><br><br clear="all"><br>-- <br>Jeff Duda<br>Iowa State University<br>Meteorology Graduate Student<br>3134 Agronomy Hall<br><a href="http://www.meteor.iastate.edu/~jdduda">www.meteor.iastate.edu/~jdduda</a><br>