<div dir="ltr"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hi,</div><div><br></div><div>I'm not sure if this is an ncl question. You should have directed your questions to the ncep help page (<a href="https://www.ncep.noaa.gov/mail_dataquestions/">https://www.ncep.noaa.gov/mail_dataquestions/</a>)</div><div><br></div><div><b>[1] </b>As far as I know, the .anl files are analyses files and were already assimilated with observations.</div></div></div></div></div></div></div></div></div></div></div><br><div><b>[2]</b> If you want to use the forecast, then use the files with the following format (<a href="https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.20210308/12/">https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.20210308/12/</a>):</div><div><br></div><div><pre style="color:rgb(0,0,0)"><a href="https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.20210308/12/gfs.t12z.pgrb2.0p25.f000">gfs.t12z.pgrb2.0p25.f000</a></pre><pre style="color:rgb(0,0,0)"><pre><a href="https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.20210308/12/gfs.t12z.pgrb2.0p25.f001">gfs.t12z.pgrb2.0p25.f001</a></pre><pre>etc..</pre><pre><font face="arial, sans-serif">No need to download the other files!</font></pre><pre><font face="arial, sans-serif">ncl_filedump </font>gfs.t12z.pgrb2.0p25.f000.grb <font face="arial, sans-serif">will give you the contents of the file. </font></pre><pre><font face="arial, sans-serif">If you want temperature, then look for the keyword "Temperature". This will give u information about the variables such as below:</font></pre><pre><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">float </span><span class="gmail-s2" style="font-variant-ligatures:no-common-ligatures;color:rgb(255,255,255);background-color:rgb(0,0,0)">TMP_P0_L102_GL</span><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">L0 ( lv_AMSL1, lat_0, lon_0 )</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>center : <span class="gmail-Apple-converted-space"> </span>US National Weather Service - NCEP (WMC)</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>production_status :<span class="gmail-Apple-converted-space"> </span>Operational products</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>long_name :<span class="gmail-Apple-converted-space"> </span>Temperature</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>units :<span class="gmail-Apple-converted-space"> </span>K</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>_FillValue : <span class="gmail-Apple-converted-space"> </span>1e+20</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>grid_type :<span class="gmail-Apple-converted-space"> </span>Latitude/longitude</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>parameter_discipline_and_category :<span class="gmail-Apple-converted-space"> </span>Meteorological products, Temperature</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>parameter_template_discipline_category_number :<span class="gmail-Apple-converted-space"> </span>( 0, 0, 0, 0 )</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>level_type : <span class="gmail-Apple-converted-space"> </span>Specific altitude above mean sea level (m)</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>forecast_time :<span class="gmail-Apple-converted-space"> </span>72</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>forecast_time_units :<span class="gmail-Apple-converted-space"> </span>hours</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>initial_time : 03/08/2021 (00:00)</span></p></pre><pre><font face="arial, sans-serif">The variable name is the same for other GFS files, regardless of resolution.</font></pre><pre><font face="arial, sans-serif"><b>[3]</b> For documentation, check this: </font><a href="https://www.emc.ncep.noaa.gov/emc/pages/numerical_forecast_systems/gfs/documentation.php">https://www.emc.ncep.noaa.gov/emc/pages/numerical_forecast_systems/gfs/documentation.php</a></pre></pre><pre style="color:rgb(0,0,0)"><font face="arial, sans-serif"><b>[4] </b>The files are archived in <a href="http://rda.ucar.edu">rda.ucar.edu</a>. For the 25km GFS, for example, see this link:</font></pre><pre style="color:rgb(0,0,0)"><a href="https://rda.ucar.edu/datasets/ds084.1/#!docs">https://rda.ucar.edu/datasets/ds084.1/#!docs</a><font face="arial, sans-serif"><br></font></pre><pre style="color:rgb(0,0,0)"><font face="arial, sans-serif"><br></font></pre><pre style="color:rgb(0,0,0)"><font face="arial, sans-serif"><br></font></pre><pre style="color:rgb(0,0,0)"><font face="arial, sans-serif">Hope this helps.</font></pre><pre style="color:rgb(0,0,0)"><font face="arial, sans-serif">--Lyndz</font></pre><pre style="color:rgb(0,0,0)"><br></pre></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Mar 8, 2021 at 8:05 PM dr.hieronymus--- via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><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>
I am trying to dig through GFS files in GRIB2 format on NCEP's FTP <br>
server (<a href="https://www.nco.ncep.noaa.gov/pmb/products/gfs/" rel="noreferrer" target="_blank">https://www.nco.ncep.noaa.gov/pmb/products/gfs/</a>).<br>
<br>
Unfortunately, it is not very easy to get a proper overview. Therefore, <br>
my first question is whether there is documentation somewhere that <br>
describes the different formats/variants in detail.<br>
<br>
What one quickly notice and easy understand is that the GFS files are <br>
available in different resolutions (0.25°, 0.50°, 1.00°) and each GFS <br>
file is described by an index file. The GFS files with 0.25° resolution <br>
have an hourly granularity and the GFS files with 0.50° and 1.00° <br>
resolution have a three-hourly granularity.<br>
<br>
Then, there are the .anl and .f000 GFS files. I don't understand the <br>
difference between .anl and .f000. Is .f000 not a forecast? Furthermore, <br>
I noticed that the index files are different regarding .f000 and <br>
.f001-384 (0.25°) and .f000 and .f003-384 (0.50°, 1.00°).<br>
<br>
What also confuses me are the different GFS files, namely pgrb2, pgrb2b, <br>
pgrb2full and sfluxgrbfFFF. What are the differences exactly? According <br>
to the corresponding index files, the same physical variables are <br>
available in all different GFS files. Do these variables always have the <br>
same values in all GFS files? Doesn't it matter which file I use when <br>
I have decided on a resolution?<br>
<br>
I am actually only interested in the temperature 2 meters above the <br>
ground. Which file should I simply use?<br>
<br>
In addition, I also wanted to know if the initial values for each model <br>
run (00, 06, 12, 18) are published somewhere.<br>
<br>
Thank you in advance for your help.<br>
_______________________________________________<br>
ncl-talk mailing list<br>
<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a><br>
List instructions, subscriber options, unsubscribe:<br>
<a href="https://mailman.ucar.edu/mailman/listinfo/ncl-talk" rel="noreferrer" target="_blank">https://mailman.ucar.edu/mailman/listinfo/ncl-talk</a></blockquote></div>