P. Jimenez, RAL/NCAR

This presentation will provide an overview of two recent extensions of the WRF-Solar model: the WRF-Solar Ensemble Prediction System (WRF-Solar EPS) and the MAD-WRF short-term prediction component. These components build on top of the original upgrades of the WRF-Solar model focused on the cloud-radiation-aerosol physics. The upgrades introduced in WRF-Solar EPS focused on providing a probabilistic system tailored for solar energy applications. To this end, we identified the most relevant variables for solar irradiance predictions from selected parameterizations to subsequently introduce stochastic perturbations in these variables. The characteristics of the perturbations and variables to perturb are controlled via a configuration file and the WRF namelist allowing for flexibility to configure the ensemble. The other extension, MAD-WRF, focuses on improving the short-term irradiance predictions. To this end, we added a cloud initialization module that can incorporate Earth observations of the cloud mask and the cloud top/base height to initialize the hydrometeors. Once, the hydrometeors are initialized, MAD-WRF can be run in two modes, both designed to sustain the analyzed clouds. The first one is referred as the passive mode and advects and diffuses the hydrometeors as tracers with no cloud microphysics. This is a good approximation for very short-term predictions. In order to extend the value of the predictions, the active mode nudges the resolved hydrometeors towards these tracers at the beginning of the simulation in an effort to develop an appropriate thermodynamic environment to support the clouds. Both models, MAD-WRF and WRF-Solar EPS, bring added value to the original WRF-Solar developments, and the added value of these models will be described based on multi-year forecasts over CONUS.