<span style=" font-size:10pt;font-family:sans-serif">Dear rNOMADS users,</span><br><br><span style=" font-size:10pt;font-family:sans-serif">I am relatively
new to GFS grib2 data processing. Need some help here. Thanks in advance.
</span><br><br><span style=" font-size:10pt;font-family:sans-serif">I ran into some
difficulty in extracting the 4 soil water content parameters from GFS reanalysis
files. </span><br><br><span style=" font-size:10pt;font-family:sans-serif">Here is the download
link for a specific file I am testing: </span><a href=https://nomads.ncdc.noaa.gov/data/gfsanl/201801/20180101/gfsanl_4_20180101_0000_006.grb2><span style=" font-size:10pt;color:blue;font-family:sans-serif">https://nomads.ncdc.noaa.gov/data/gfsanl/201801/20180101/gfsanl_4_20180101_0000_006.grb2</span></a><span style=" font-size:10pt;font-family:sans-serif"></span><br><br><span style=" font-size:10pt;font-family:sans-serif">I would like to
extract 4 parameters using this R package. I have the grb2 file downloaded
to my local computer. </span><br><br><span style=" font-size:10pt;font-family:sans-serif">library(rNOMADS)</span><br><span style=" font-size:10pt;font-family:sans-serif">fpath<-"gfsanl_4_20180101_0000_006.grb2"</span><br><span style=" font-size:10pt;font-family:sans-serif">variables<-c("SOILW")</span><br><span style=" font-size:10pt;font-family:sans-serif">levels<-c("0.1-0.4
m below ground") # I want to test one parameter first</span><br><span style=" font-size:10pt;font-family:sans-serif">export_data<-
ReadGrib(fpath,levels=levels,variables=variables)</span><br><br><span style=" font-size:10pt;color:blue;font-family:Lucida Console">>
str(export_data)<br></span><span style=" font-size:10pt;font-family:Lucida Console">List of
9<br> $ model.run.date: chr(0) <br> $ forecast.date : chr(0) <br> $ variables     : chr(0) <br> $ levels        : chr(0) <br> $ lon           : num(0) <br> $ lat           : num(0) <br> $ value         : chr(0) <br> $ meta.data     : chr "None - this field is used for grib1
files"<br> $ grib.type     : chr "grib2"</span><br><br><span style=" font-size:10pt;font-family:Lucida Console">What did I
do wrong here? </span><br><br><span style=" font-size:10pt;font-family:Lucida Console">There are
4 SOILW parameters at different levels: </span><br><span style=" font-size:10pt;font-family:Lucida Console">[271] "271:43400382:d=2018010100:SOILW:0-0.1
m below ground:6 hour fcst:"</span><br><span style=" font-size:10pt;font-family:Lucida Console">[273] "273:43583330:d=2018010100:SOILW:0.1-0.4
m below ground:6 hour fcst:"     </span><br><span style=" font-size:10pt;font-family:Lucida Console">[275] "275:43764744:d=2018010100:SOILW:0.4-1
m below ground:6 hour fcst:"       </span><br><span style=" font-size:10pt;font-family:Lucida Console">[277] "277:43943879:d=2018010100:SOILW:1-2
m below ground:6 hour fcst:"         </span><br><br><span style=" font-size:10pt;font-family:Lucida Console">When I change
the variables to the 4th layer above, then it returns some data. It also
works with the other 3 variables I am interested shown below: </span><br><span style=" font-size:10pt;font-family:Lucida Console">[286] "286:45186361:d=2018010100:TMAX:2
m above ground:0-6 hour max fcst:"      </span><br><span style=" font-size:10pt;font-family:Lucida Console">[287] "287:45421594:d=2018010100:TMIN:2
m above ground:0-6 hour min fcst:"      </span><br><span style=" font-size:10pt;font-family:Lucida Console">[293] "293:46556801:d=2018010100:APCP:surface:0-6
hour acc fcst:"        </span><br><br><span style=" font-size:10pt;font-family:Lucida Console">Also gdal_translate
will get the data out, for example temperature will be in C unit, but if
I use the above command for the TMAX and TMIN, the unit seems to be K?
</span><br><br><span style=" font-size:10pt;font-family:sans-serif">Thanks & Regards,<br>Cheyenne</span><BR>