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Another look at the contingency tables: scores based on Manhattan distances in the phase space

✍ Scribed by Joël Stein


Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
261 KB
Volume
18
Category
Article
ISSN
1350-4827

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✦ Synopsis


Abstract

This alternative presentation of scores is based on the Manhattan distance in the phase space of forecasts. The key factor is represented by the ratio of the weights assigned to misses and false alarms. This ratio is 1 for the Heidke skill score and is equal to the ratio of the number of non‐events to the number of events for the Pierce skill score. A score based on the deterministic limit leads to assign this ratio to either 2 or 0.5 as a function of the base rate. It can also be determined as a function of parameters of a cost‐loss economical model.

Applied to the Finley tornadoes and to two quantitative precipitation forecasts, the geographical representation of the phase space is quite invaluable as it points out the good points and the drawbacks of the forecast. The skill scores deduced from these distances help to summarize the quality of a forecast. Copyright © 2010 Royal Meteorological Society