Since 2003, the MMM division at NCAR has been experimenting cloud-permitting
scale weather forecasting using Weather Research and Forecasting (WRF) model.
Over the years, we've tested different
model physics, and tried different initial and boundary conditions.
Not surprisingly, we found that the model's forecasts are more sensitive
to the initial conditions than model physics. In 2012 real-time experiment,
WRF-DART (Data Assimilation Research Testbed) at 15 km was employed to
produce initial conditions for twice-a-day forecast at 3 km.
On June 29, this forecast system captured one of the most destructive
derecho event on record. In this presentation, we will examine forecast
sensitivity to different model initial conditions, and try to understand
the important features that may contribute to the success of the forecast. |