Meteorology / ARL Data FTP / Archive

The ARL web server contains several meteorological model data sets already converted into a HYSPLIT compatible format on the public directories. Direct access via FTP to these data files is "hardwired" into the GUI. Only an email address is required for the password to access the server. The "FTP menu" is locked until the FTP process is completed, at which point a message box will appear indicating the file name that was just transferred.

The ARL analysis data archive consists of output from the Global Data Analysis System (GDAS/GFS) and the North AMerican (EDAS/NAM) Data Analysis System. Data archives are available at various temporal and spatial resolutions. See notes below for a more detailed discussion of each file.

• EDAS :: 40 km 3P (>=2004 SM 650 Mb) Semi-Monthly (1-15; 16-end) data files at three hour intervals on pressure surfaces
• GDAS :: 1-deg 3P (>=2005 WK 600 Mb) Weekly files (W1=1-7; W2=8-14; W3=15-21; W4=22-28; W5=29-end) every three hours on pressure surfaces
• GDAS :: 0.5-deg 3S (September 1, 2007 - June 11, 2019 DA 500 Mb) Daily files every three hours on the native GFS hybrid sigma coordinate system.
• GFS.v1 :: 0.25-deg 3S (May 13, 2016 - June 12, 2019 DA 2500 Mb) Daily files every three hours on the native GFS hybrid sigma coordinate system. NCEP GFS.v14
• GFS :: 0.25-deg 3S (>= June 13, 2019 DA 2500 Mb) Daily files every three hours on the native GFS hybrid sigma coordinate system. NCEP GFS.v15(fv3)
• HRRR.v1 :: 3 km 1S (June 15, 2015 - July 23, 2019 DA 3500 Mb) Hourly HRRR output on sigma surfaces in four files per day (00-05, 06-11, 12-17, and 18-23). The forecast hour is +1 for all times.
• HRRR :: 3 km 1S (>=June 13, 2019 DA 3500 Mb) Hourly HRRR output on sigma surfaces in four files per day (00-05, 06-11, 12-17, and 18-23). The forecast hour is +0 for all times.
• NAM12 :: 12-km 3P (>=2007 DA 450 Mb) Composite archive 0 to +6 hour forecasts appended into daily files for the CONUS at three hour intervals on pressure surfaces
• NAMs :: 12 km 1S (>=2010 DA 1300 Mb) Composite archive 0 to +6 hour forecasts appended into daily files for the CONUS at one hour intervals on sigma surfaces
• NAMs-AK :: 12 km 1S (>=2010 DA 750 Mb) Composite archive 0 to +6 hour forecasts appended into daily files for Alaska at one hour intervals on sigma surfaces
• NAMs-HI :: 2 km 1S (>=2010 DA 500 Mb) Composite archive 0 to +6 hour forecasts appended into daily files for Hawaii at one hour intervals on sigma surfaces
• NARR :: 32 km 3P (>=1979 MO 3000 Mb) North American Regional Reanalysis on pressure surfaces at three hour intervals in monthly files
• WRF :: 2.5 deg 6P (>=1948 DA 220 Mb) NCAR/NCEP global reanalysis on pressure surfaces at six hour intervals in monthly files
• WRF :: 27 km 3S (>=1980 DA 220 Mb) Houly WRF output in daily files on sigma surfaces where initial and boundary conditions were taken from the NARR

Depending upon how the data is archived, from the GUI it is necessary to enter at least the year and month. For other data sets the day and hour (HRRR only) may be required. The file names are created automatically.

Global NOAA-NCEP/NCAR pressure level reanalysis data archives were reprocessed into the HYSPLIT compatible format and are available on ARL's web site from 1948. More information about the reanalysis project and data can be found at the CDC web site.

A comparable data set is also available from ECMWF's 40 year reanalysis project. The GRIB files must be downloaded independently from the GUI through a web browser. Although cost free, registration with ECMWF is required. The downloaded ECMWF GRIB data files may be converted through the GUI to the ARL format.

Additional information about the data archives on the ARL server can be found at the ARL web page.