CAPS Storm Scale Ensemble Forecast System (SSEF)

SSEF is based upon the WRF-ARW modeling system. It is a 10 ensemble members (hybrid: initial perturbation + physics perturbation) with 4 km horizontal grid spacing and 51 vertical levels. Forecast is initiated at 00 and 12 UTC with run lengths of 30 h and 18 hr respectively. WSR-88D radar data are assimilated at 0000 UTC for all but c0 members. Eight members have  initial perturbations added. The 00 UTC initialization has a larger domain, while the 12 UTC run has a domain over the central US.

DTC will be evaluating two members of the SSEF; specifically, the c0 member (no radar assimilation) and the non-perturbed member containing radar assimilation.

High Resolution Rapid Refresh (HRRR)

The HRRR is a 3-km resolution, hourly updated, cloud-resolving atmospheric model, initialized by DFI-fields from the 13km radar-enhanced Rapid Update Cycle (RUC) run at NOAA/ESRL/GSD. (soon to be initialized similarly by the 13km radar-assimilating Rapid Refresh ).

The HRRR uses a configuration of the WRF-ARW model, similar to that used for the Rapid Refresh (i.e. Thompson microphysics, RUC-Smirnova land-surface model, etc., as defined on the NOAA Rapid Refresh website ). However, it does not use any convective parameterization.HRRR is initialized with latest 3-d radar reflectivity via 13km backup RUC at ESRL/GSD, which includes radar reflectivity assimilation via its radar-DFI (digital filter initialization) technique. It also now covers approximately the eastern 2/3 of the lower 48 US.

The DTC will be evaluating the forecasts from the 00 UTC and 12 UTC initializations.