Documentation of the Evaluation of CALPUFF and Other Long ...

experienced during the original ETEX exercise if forecast fields rather ECMWF analysis
fields had been employed. Additionally, the MM5 simulation has the added advantage of
data assimilation to constrain the growth of forecast error as a function of time.
• Second, since each of the five LRT model platforms evaluated in this project are presented
with the same meteorological database; a systemic degradation of performance due to
advection error would have been observed if the meteorology was a primary source of
model error. However, since poor model performance was only noted in one of the five
models, meteorological error was not considered the primary cause of poor performance.
• Finally, since wind direction is likely one of the key meteorological parameters for LRT
simulations, the operational decision to use the existing MM5 forecasts was made
because the MM5 wind direction forecasts were within acceptable statistical limits.
2
1
0
‐1
‐2
6
5
4
3
2
1
0
23‐Oct
23‐Oct
24‐Oct
24‐Oct
WS Bias (m/s)
25‐Oct
Figure 6‐4a. ETEX MM5 model performance statistics of Bias (top) and RMSE (bottom) for
wind speed and comparison with benchmarks (purple lines).
108
26‐Oct
WS RMSE (m/s)
25‐Oct
26‐Oct
27‐Oct
27‐Oct
Avg
Avg