HYSPLIT Forum: hysplitbbs.arl.noaa.gov

I am trying to run a backwards cluster analysis but I am unsure how to do so. Currently I am using the GUI to setup the run (control file attached) if I use a negative time in the setup and then run daily (12hrs 29 days 0hrs after the start) clustering I get the error:

Model started ... it is slower at the beginning
Started Cluster (Version: April 2015)
ERROR - <Hours to cluster> must be greater than 0
-48
998

If I run with a positive time gives the attached plot where the source location located far from the spread. I'm not sure where my error is

Thanks

Hi,
Time steps in clustering specifies how many endpoints lines you like to use in clustering calculation (always positive). It is different from the time step in trajectory runs where negative time step indicates the backward simulation.