A Look at the Performance of the Next Version of the HRRR Model for Some Recent Heavy Precipitation/High Impact Events

The second-generation operational version of the High Resolution Rapid Refresh (HRRR) model, developed at NOAA/ESRL/GSD and run operationally at NCEP, is on track to be updated to its next version (HRRRv3) in May 2018. The HRRR is the only operational NCEP convection-allowing model with a new run every hour. The HRRR became an operational model at NCEP on 30 September 2014, after being available to forecasters for several years previously on an experimental basis from GSD in Boulder. Currently the HRRR is run once per hour at NCEP out to 18 h at a horizontal grid resolution of 3 km. It is initialized with the RAP (Rapid Refresh model) model, which is run at NCEP at a resolution of 13 km once per hour out to 21 hours, but the HRRR assimilates radar and other data on the 3-km scale. A number of improvements to the RAP (which is scheduled to be updated at NCEP at the same time) and HRRR will be in the next version. In addition to the model upgrades, the HRRRv3 forecasts run at NCEP will be extended to 36 h in length at 6-h intervals (00, 06, 12 and 18 UTC). As a test of these longer forecasts this next version of the HRRR has been run at ESRL (HRRRX) for some time, with forecasts out to 36 h at 06 UTC and 18 UTC and to 48 h at 12 UTC and 00 UTC. In this talk we will focus on the performance of these longer-range forecasts from the next version of the HRRR for a variety of recent high impact/significant precipitation events, including those producing heavy rainfall and others that mainly produced significant snowfall and/or icing. Events across a variety of areas in the CONUS will be examined and discussed in this presentation.