Can an ensemble give anything more than Gaussian probabilities?

Autor: J. C. W. Denholm-Price
Jazyk: angličtina
Rok vydání: 2003
Předmět:
Zdroj: Nonlinear Processes in Geophysics, Vol 10, Iss 6, Pp 469-475 (2003)
Druh dokumentu: article
ISSN: 1023-5809
1607-7946
Popis: Can a relatively small numerical weather prediction ensemble produce any more forecast information than can be reproduced by a Gaussian probability density function (PDF)? This question is examined using site-specific probability forecasts from the UK Met Office. These forecasts are based on the 51-member Ensemble Prediction System of the European Centre for Medium-range Weather Forecasts. Verification using Brier skill scores suggests that there can be statistically-significant skill in the ensemble forecast PDF compared with a Gaussian fit to the ensemble. The most significant increases in skill were achieved from bias-corrected, calibrated forecasts and for probability forecasts of thresholds that are located well inside the climatological limits at the examined sites. Forecast probabilities for more climatologically-extreme thresholds, where the verification more often lies within the tails or outside of the PDF, showed little difference in skill between the forecast PDF and the Gaussian forecast.
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