<div dir="ltr"><div><div><div><div>Hi,<br><br></div>The GFS will have hourly output up to 120 hours. However, to remain<br></div>compatible with the older forecast files, the precip is accumulated for<br></div>6 hours before resetting the bucket. You can get the hourly (or 3 hourly<br></div><div>for the forecast hour > 120) by<br><br></div><div> cat gfs.t06z.pgrb2.0p25.f??? | \<br> wgrib2 - -match APCP -set_grib_type c1 -ncep_norm apcp.grb<br><br></div><div>Line 1: takes all the hourly gfs forecasts: gfs.t06z.pgrb2.0p25.f000, gfs.t06z.pgrb2.0p25.f001<br>,.., gfs.t06z.pgrb2.0p25.fNNN and writes it stdout<br><br></div><div>Line2: wgrib2 - (read grib file from stdin)<br></div><div> -match APCP (only process APCP)<br></div><div> -set_grib_type c1 (write out in complex1 packing)<br></div><div> -ncep_norm apcp.grb (make hourly and write to apcp.grb).<br><br></div>Wesley<br><br><a href="http://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/ncep_norm.html">http://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/ncep_norm.html</a><div class="gmail_extra"><br><div class="gmail_quote">On Mon, May 2, 2016 at 6:33 AM, Ivan Toman <span dir="ltr"><<a href="mailto:ivtoman@inet.hr" target="_blank">ivtoman@inet.hr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello,<br>
<br>
As new GFS has 1hr output step, it would be nice to normalize<br>
precipitation amount in grib files to 1h. To do this I tried, after<br>
downloading gribs in 1h step:<br>
cat *.gfs.* > gfs.grib2<br>
wgrib2 gfs.grib2 -set_grib_type c1 -ncep_norm normalized_gfs.grib2<br></blockquote><div><br></div><div>The problem is that -ncep_norm takes a specific format. All the APCP<br></div><div>have to be grouped together.<br></div><div><br> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
g2ctl -verf normalized_gfs.grib2 >n_gfs.ctl<br>
gribmap -i n_gfs.ctl<br>
<br>
Then open n_gfs.ctl in GrADS, however, it seems to me that precipitation<br>
is not being normalized correctly.<br>
<br>
Am I missing something?<br>
<br>
Is there any other way to get nice 1h precipitation steps in grib files<br>
or can you suggest GrADS way to do 1h precipitation without normalizing<br>
gribs first?<br>
<br>
Thank you,<br>
Ivan Toman<br>
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</blockquote></div><br></div></div>