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<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009>Hello!</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>in our institution,
in order to speed up some operational tasks, we are starting to work with
regional subsets of global 0.5-GFS GRIB2 files as inital/boundary conditions for
WRF (we are using "small_grib" option of wgrib2 to generate our regional subset)
as you can observe in the attached document</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>We have found some
significant differences in WRF results due to use of those regional files
instead of global files. We've contacted with people at NCEP related to grib2
processing, and they said that this is normal, wgrib2 just "generates" some
truncation errors, and the differences in WRF results are similar to those
obtained using the same initial conditions in differente
machines/compilers.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>Even though, it
seems that the differences are really important (non-negligible)... does anyone
has faced with this kind of problem? any suggestions?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>Thanks in
advance!</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=194425509-26032009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>Eduardo
Penabad</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=194425509-26032009>MeteoGalicia. NWP
Department</SPAN></FONT></DIV></BODY></HTML>