This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
>From: address@hidden >Organization: . >Keywords: 199909132120.PAA07611 > >Steve, > >Thanks for the information you sent me about the trajectory program. >We have all the executables but for some reason they were never >copied to $GEMEXE so I did not know they were there. Do you think >the package would work with RUC model analysis? I would like to >try this since I could get an analysis every 3 hours and would not >have to worry about forecast errors (just analysis errors!) > >Donna Tucker http://chinook.phsx.ukans.edu/tucker.html >address@hidden Department of Physics and Astronomy >(785) 864-4738 (new area code!) University of Kansas >(785) 864-5262 (fax) Lawrence, KS 66045-2151 > > Donna, The basic program will work for RUC grids, but is currently hardwired to step through forecast times of a single run rather than multiple analysis times. I can modify the program accordingly, as well as the scripts which currently dump out the model fields for each forecast time and then the program uses f000 for steps 0-2 hours, f006 for 3-8 hours, f012 for 9-14 hours etc. Actually, thr program really doesn't care about what is in the gdlist output files, but the ETA and AVN both use a 6 hour time step. To use 3 hourly RUC analyses, the case statement in trajectory_gem.c and back_traj.c will have to be updated to know at what time step to open the next set of grids for a given model time. If you will have 3 hourly run analyses (actually you can get hourly RUC2 analyses from: ftp://140.90.88.142/ncepe/pggrib) how many runs do you think you would be using- and are you planning on doing this for a particular case or in real time for some last xxx hours? Steve Chiswell