HYSPLIT Forum: hysplitbbs.arl.noaa.gov

Hello,

I had a question about the HRRR files you are archiving on the website: ftp://arlftp.arlhq.noaa.gov/archives/hrrr/.

I have started testing out running Hysplit using these files and I get the message (in the MESSAGE file) that:

Simulation Date (CCYYMMDD): 20170530
Simulation Time (HHMMSS.S): 084602.733
WARNING: metini - FLUXES not found in data (kg,kt) 1 1
Setting KBLS=2 to use the wind/temp profiles!

So it seems like heat and momentum fluxes are not part of the surface variables in the HRRR ARL files and since I had set KBLS=1, it is now going to KBLS=2 to use the wind/temp profiles instead. Is that correct?

From the readme.txt, the variables are:

Sfc Variables: 24 SHGT PRSS MSLP TPP1 DIFR T02M DP2M PBLH DSWF
ULWF U10M V10M VSBY CSNO CICE CFZR CRAI LIB4
CAPE CINH TCLD REFC CLDB CLDT
Upper Levels: 8 PRES TEMP UWND VWND WWND DIFW SPHU TKEN

I don’t know which variables it needs to use the fluxes. Is this a mistake I am making or is simply defaulting to KBLS=2 going to be the only way to run Hysplit with these files?

Thanks very much,
Anna Karion
NIST

Unfortunately, we are not extracting the heat or momentum fluxes from the HRRR datasets. The model will default to use the temperature/wind profile to determine the stability conditions (KBLS=2). KBLS defines how the stability is computed. Normally when turbulent fluxes (heat and momentum) are available from the meteorological data file, they are used to compute stability. Sometimes it may be desirable to force the stability to be computed from the wind and temperature profiles, especially if the fluxes represent long-time period averages rather than instantaneous values. If fluxes are not present, the profiles are used for the stability computation.