Data Sources

• Op40 (Operational 13-km RUC run at NCEP, interpolated to a 40-km grid for speed of loading.) This is generally the best data source to use, because it loads quickly.
• Bak40 (Backup 13-km RUC run at GSD, interpolated to a 40-km grid for speed of loading.) This is a good backup when Operational RUC soundings are not available.
• GFS (Global Forecast System, run at NCEP.) This provides soundings on a 0.5 degree grid worldwide. GFS runs every 6 hours, and forecasts are available from this site in 3 hour increments out to 180 hours. This is currently your only option for model soundings beyond the contiguous US.
• Dev1320 (Development 13-km RUC run at GSD, interpolated to a 20 km grid.) This is mostly for internal use, and like all the 20-km grids, loads more slowly than the above models.
• Op20 (Operational 13-km RUC run at NCEP, interpolated to a 20-km grid.) This is the same as Op40, but on a 20-km grid. It loads much more slowly than Op40, and places a considerable load on our server. The Op40 should be used in preference to this, unless there is a compelling reason for using 20-km grid data.
• Bak20 (Backup 13-km RUC run at GSD, interpolated to a 20-km grid.) This is the same as Bak40, but on a 20-km grid. It loads much more slowly than Bak40, and places a considerable load on our server. The Bak40 should be used in preference to this, unless there is a compelling reason for using 20-km grid data.
• dev and dev2 (Paired RUC cycles on a 20-km grid run at GSD.) These models have nearly all the properties of the Operational RUC, but are run natively at 20-km. dev2 includes TAMDAR data, and dev does not. Otherwise they are identical. These cycles are saved at many airports for 60 days, and are saved at RAOB sites since 23 Feb 2006. So, for soundings older than about 24 hours, these are good to use. dev2 has somewhat better skill than dev, particularly in the U.S. Midwest where TAMDAR flies. Both models have skill approximately equal to that of the Operational 13-km RUC.
• RAOBs (Radiosondes.) These are available worldwide, for approximately the past 60 years.