Online HYSPLIT for registered users (at https://www.ready.noaa.gov/HYSPLIT_disp.php) supports the modeling of chemical dispersion and produces plume concentrations in parts per million (ppm). Both the NAM CONUS Nest (CNEST) and HRRR provide meteorological data at 3 km resolution. HRRR is updated every hour, whereas NAM CNEST is updated every six hours. HRRR should therefore be the first choice, followed by NAM CNEST.
Statistics: Posted by sonny.zinn — November 25th, 2025, 6:38 am