High Resolution Rapid Refresh”— A 2-3 kilometer, very high resolution weather model, the HRRR re-run and updated every hour. The forecasts for the HRRR extend out 18 hours, but the 00z, 06z, 12z and 18z model runs extend forecasts out to 48 hours The HRRR is one of several new “CAM” models. CAM is “Convection Allowing Model”.