1B.3 Characteristics of Convective Initiation in High-Resolution Simulations: Object-Based Validation Using Geostationary Satellite Observations

Monday, 13 January 2020: 9:00 AM
257AB (Boston Convention and Exhibition Center)
D. Henderson, Univ. of Wisconsin–Madison, Madison, WI; and J. A. Otkin, J. Mecikalski, D. Haliczer, and X. Li

High-resolution NWP models are a useful tool for obtaining a better understanding of the processes related to cloud and precipitation formation; however, the spatial extent and life-cycle of simulated clouds are quite sensitive to the assumptions made by cloud microphysics parameterization schemes. These differences can lead to various outcomes on when the first occurrence of rainfall or convective initiation (CI) is observed. This study takes advantage of new high temporal resolution data from the GOES-16 Advanced Baseline Imager (ABI) to track and evaluate the life-cycle of CI events produced by high-resolution Weather Research and Forecasting (WRF) model simulations employing different parameterization schemes. Simulated GOES-16 ABI infrared brightness temperatures are generated for each forecast using the Community Radiative Transfer Model (CRTM) and then compared to real ABI observations to assess the accuracy of the simulated CI events. To validate, distinct cloud objects are constructed over time using the observed GOES-16 ABI and simulated IR brightness temperatures for several CI case studies across the eastern United States. Through composite analysis the spatial extent, occurrence, and life-cycle of CI events are analyzed using CI interest fields implemented in forecasts derived from geostationary satellite observations. The object-based comparisons aid in producing a robust evaluation of the simulated cloud properties for two related goals. The first goal is to use the real ABI observations to assess the accuracy of the cloud fields in the WRF model simulations, whereas the second goal is to use the high-resolution simulations to gain greater understanding regarding the cloud processes occurring deeper within the convective clouds that lead to various cloud-top signatures depicted in ABI imagery. The comparisons presented in this work represent an initial step toward assessing the ability of various cloud microphysics schemes to accurately forecast cumulus growth and convective initiation when used in high-resolution (~ 1 km) model simulations.
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