======================================================================= readme_gfs0p25_info_pre-20161201.txt 03 Nov 2017 ======================================================================= Change in text below, folder (directory) from archives-1 to archives ======================================================================= readme_gfs0p25_info_pre-20161201.txt ?? ======================================================================= Change filename of this file from readme_gfs0p25_missings.txt to readme_gfs0p25_info_pre-20161201.txt ======================================================================= readme_gfs0p25_info.txt 13 May 2016 ======================================================================= Begin archive of concatenated short-term NCEP Global Forecast System (GFS) forecast model output having a quarter-degree latitude-longitude grid on native model (hybrid) levels. The zero and three hour (+0, +3) forecasts from successive (6-hourly) GFS runs are concatenated to make the pseudo-analysis. 21 hours of model output are in a single file. Model output is at 3-hour intervals. The notation "0p25" means 0.25 degrees resolution. These files are created on an NCEP development-access computer which is sometimes unavailable because of maintenance or NCEP operations testing, or there may be other reasons which can cause files to be 'missing', These are not able to be re-created. Data: ftp://ftp.arl.noaa.gov/archives/gfs0p25/ This file: ftp://ftp.arl.noaa.gov/archives/gfs0p25/readme_gfs0p25_info_pre-20161201.txt Missings: ftp://ftp.arl.noaa.gov/archives/gfs0p25/readme_gfs0p25_missings.txt Description of other archived data in this format for HYSPLIT: http://www.ready.noaa.gov/archives.php *********************************************************************** ----------------------------------------------------------------------- Data fields, 4-character identifier, units ----------------------------------------------------------------------- Surface or single level: PRSS hPa surface pressure MSLE hPa mean sea level pressure UMOF N/m2 u-component of momentum flux VMOF N/m2 v-component of momentum flux TPP6 m precipitation, 6-hourly accumulation SHTF W/m2 sensible heat net flux DSWF W/m2 downward short wave radiation flux SPH2 kg/kg specific humidity at 2 meters AGL U10M m/s u wind component at 2 meters AGL V10M m/s v wind conponent at 2 meters AGL T02M K temperature at 2 meters AGL TCLD % total cloud cover PBLH m planetary boundary layer height LHTF W/m2 latent heat net flux USTR m/s friction velocity RGHS m surface roughness PTRO hPa pressure at the tropopause 3-dimensional: TEMP K temperature UWND m/s u wind component VWND m/s v wind component WWND hPa/h w wind component SPHU kg/kg specific humidity PRES hPa pressure *********************************************************************** ----------------------------------------------------------------------- File creation ----------------------------------------------------------------------- NOAA NWS NCEP runs numerical weather prediction (NWP) models. This archive contains output from the NCEP GFS model (http://www.emc.ncep.noaa.gov/index.php?branch=GFS). NOAA OAR ARL processes the NCEP output into the HYSPLIT-compatible format. Since NCEP runs the GFS 4 times a day, at 00, 06, 12, and 18 UTC, each day's file is a concatenation of successive 0-hour initialization and 3-hour forecasts from the 4 daily runs. In addition some 6-hour forecast fields are written to the 0-hour valid times (00, 06, 12, 18 UTC) because they are not output by NCEP at the the 0-hour initialation time. ----------------------------------------------------------------------- These files are not created in a 24x7 operational environment. ----------------------------------------------------------------------- A missing file can result when ARL's processing job fails. Failures can be caused by computer outages, file transfer failures, or other reasons. If files are missing please use the GDAS0P5 (half-degree). See http://ready.arl.noaa.gov/archives.php ----------------------------------------------------------------------- 55 hybrid sigma-pressure Levels ----------------------------------------------------------------------- 0.9999, 0.9947, 0.9886, 0.9817, 0.9739, 1.9648, 1.9544, 2.9425, 4.9288, 6.9132, 8.8954, 11.875, 16.853, 21.827, 26.799, 33.769, 41.735, 49.699, 59.660, 69.619, 80.576, 91.531, 102.49, 113.44, 123.39, 133.35, 143.30, 151.26, 157.22, 162.18, 165.15, 166.12, 165.09, 162.07, 157.05, 150.04, 142.02, 132.01, 122.01, 111.00, 99.002, 88.000, 78.000, 68.000, 59.000, 52.000, 45.000, 39.000, 34.000, 29.000, 25.000, 21.000, 18.000, 15.000, 13.000 The pressure level is defined as: P = A + .B*PRSS, where PRSS is the surface pressure and A.B is defined as the level (ie., 16.853 = 869 hPa when the surface pressure is 1000 hPa [P=16+0.853*1000]) ----------------------------------------------------------------------- quarter-degree horizontal grid ----------------------------------------------------------------------- 1440 x 721 gridpoints ----------------------------------------------------------------------- Acronyms - Web sites ----------------------------------------------------------------------- ARL - Air Resources Laboratory - http://www.arl.noaa.gov/ NCEP - National Centers for Environmental Prediction - http://www.ncep.noaa.gov/ NOAA - National Oceanic and Atmospheric Administration - http://www.noaa.gov/ NWS - National Weather Service - http://www.weather.gov/ OAR - Office of Oceanic and Atmospheric Administration - http://www.oar.noaa.gov/ -----------------------------------------------------------------------