High Resolution Rapid Refresh”— The HRRR model is a very high resolution weather model (2-3 kilometers). It is run every hour and it takes about 1.3 -2 hours to for each model run to be computed and become available. The HRRR models the weather for the Continental US, Hawaii, Alaska and its territories.

The HRRR forecasts out to 18 hours in the future , but the 00z, 06z, 12z, and 18z model runs now forecast out to 48 hours.

The HRRR is one of several new “Convection Allowing Models”. (referred to as CAM models). It includes physics specific for the parameterization of convection-type rain (thunderstorms).