Mesoscale modeling and plans for DTC Ensemble Testbed (DET) development activities within ESRL/GSD

Isidora Jankov


Forecast Applications Branch (FAB) of ESRL’s Global System Division in Boulder, Colorado has been part of multiple projects involving ensemble forecasting approach. These projects have addressed forecasting of various mesosacle phenomenon such as, orographically induced precipitation in California during the winter season and the spring season convective weather in Midwest. Recently a decision has been made to organize the DTC Ensemble Testbed (DET), in which planning and development the FAB will be heavily involved.

The National Oceanic and Atmospheric Administration (NOAA) established the Hydrometeorological Testbed (HMT) to design and support a series of field experiments to better understand and forecast precipitation in the Central Valley. The main goal of the FAB has been to provide real time ensemble Quantitative Precipitation Forecast (QPF) and Probabilistic QPF (PQPF). Also, FAB scientists collaborated with researchers from ESRL Physical Sciences Division (PSD) on several studies involving mesoscale modeling and ensemble simulations related to the HMT project. These studies focused on atmospheric river events. One study’s objective was to improve QPF by estimating the impact that various microphysical schemes, Planetary Boundary Layer (PBL) schemes, and initialization methods have on cold season, primarily orographically-induced precipitation. Other research highlighted the evaluation of various microphysical schemes’ performance (e.g. Lin, WSM6, Ferrier, Thompson and Morrison) by using available observational data sets. Relevant mesoscale attributes for simulated storms were evaluated based on observations from 915-MHz wind profilers, vertically pointing S-band radars and collocated GPS water-vapor sensors, and surface meteorological instrumentation. The value of using synthetic satellite imagery to evaluate the performance of various microphysical schemes was assessed. For this purpose, synthetic GOES-10 imagery at 10.7 nm was produced.

FAB has also worked on development of high resolution, frequent update analyses and forecasts of QPF associated with Mesoscale Convective Systems (MCSs) affecting the Midwest during the spring and early summer. Presently the model simulations are initialized by using high resolution diabatic initialization from Local Analysis and Prediction System (LAPS). In the future for this purpose a new generation of LAPS analysis, variational and multi-scale Space-Time Mesoscale Analysis System (STMAS) will be used.