## the QPF project from the "user" perspective

#### or: a subjective search for the best parameterization

CoSMo General Meeting, Athens 2007

HNMS run all the proposed experiments and compared the results with "actual" observations. Since HNMS had no radar data, the forecasts were compared against the 24hrs synoptic observations of 60 stations, for three dates in 2005:

15-Sept | exceptionally heavy precipitation north of Athens
23-Nov | precipitation over nearly all of Greece, heavier along the SW-NE axis, especially over Athens
26-Nov | precipitation along the E-W axis (rather light), with two heavier concentrations (SW and E-NE)

In order to have a first indication of the "best" parameterization, we produced charts of the synoptic data and full-field model forecasts. Such results were presented in the QPF Workshop of 8 March 2007.
Unfortunately, we saw no clear hint then, possibly because the contours created by the 60 synoptic-points and the 30,000 model-points were NOT comparable!

So we tried a different approach: we redraw the model-forecasts using only the total precipitation values over the 60 synoptic stations. Now the results are directly comparable and each model forecast was given a score by a forecaster:

| Failed: the forecast is unrealistic
| Indifferent: the forecast is not (overtly) wrong, yet it does not give a clear indication
| Succeeded: The forecast matches enough (as models go) the actual weather

Here are the revised comparisons and their scores