Why models have forecast problems
Initialization and quality control smoothes data fields. Some of the lost detail may be important.
Lack of data over the oceans and Mexico.
Atmospheric processes are non-linear; small changes in initial conditions can lead to large forecast variations (this is the basis for ensemble forecasting).
Terrain may not have sufficient resolution
Model physics are approximations
- for lower resolution models (OUR CURRENT OPERATIONAL MODELS) convection is parameterized
- for higher resolution models the micro-physical processes are parameterized .
How do we judge uncertainty?