Landman, WABeraki, Asmerom F2012-03-292012-03-292012-02Landman, W.A. and Beraki, A.F. 2012. Multi-model forecast skill for mid-summer rainfall over southern Africa. International Journal of Climatology, vol. 32(2), pp 303-3140899-8418http://onlinelibrary.wiley.com/doi/10.1002/joc.2273/fullhttp://hdl.handle.net/10204/5701Copyright: 2012 Wiley. This is the post-print version of the work. The definitive version is published in International Journal of Climatology, vol. 32, pp 303–314. doi: 10.1002/joc.2273Southern African December-January-February (DJF) probabilistic rainfall forecast skill is assessed over a 22-year retroactive test period (1980/1981 to 2001/2002) by considering multi-model ensembles consisting of downscaled forecasts from three of the DEMETER models, the ECMWF, Meteo-France and UKMO coupled ocean-atmosphere general circulation models. These models are initialized in such a way that DJF forecasts are produced at an approximate 1-month lead time, i.e. forecasts made in early November. Multi-model forecasts are obtained by: i) downscaling each model’s 850 hPa geopotential height field forecast using canonical correlation analysis (CCA) and then simply averaging the rainfall forecasts; and ii) by combining the three models’ 850 hPa forecasts, and then downscaling them using CCA. Downscaling is performed onto the 0.5° × 0.5° resolution of the CRU rainfall data set south of 10° south over Africa. Forecast verification is performed using the relative operating characteristic (ROC) and the reliability diagram. The performance of the two multi-model combinations approaches are compared with the single-model downscaled forecasts and also with each other. It is shown that the multi-model forecasts outperform the single model forecasts, that the two multi-model schemes produce about equally skilful forecasts, and that the forecasts perform better during El Nino and La Nina seasons than during neutral years.enSouthern Africa rainfall forecastSeasonal forecastingClimatologyProbabilistic rainfall forecast skillEl Nino-Southern OscillationENSOArticleLandman, W., & Beraki, A. F. (2012). Multi-model forecast skill for mid-summer rainfall over southern Africa. http://hdl.handle.net/10204/5701Landman, WA, and Asmerom F Beraki "Multi-model forecast skill for mid-summer rainfall over southern Africa." (2012) http://hdl.handle.net/10204/5701Landman W, Beraki AF. Multi-model forecast skill for mid-summer rainfall over southern Africa. 2012; http://hdl.handle.net/10204/5701.TY - Article AU - Landman, WA AU - Beraki, Asmerom F AB - Southern African December-January-February (DJF) probabilistic rainfall forecast skill is assessed over a 22-year retroactive test period (1980/1981 to 2001/2002) by considering multi-model ensembles consisting of downscaled forecasts from three of the DEMETER models, the ECMWF, Meteo-France and UKMO coupled ocean-atmosphere general circulation models. These models are initialized in such a way that DJF forecasts are produced at an approximate 1-month lead time, i.e. forecasts made in early November. Multi-model forecasts are obtained by: i) downscaling each model’s 850 hPa geopotential height field forecast using canonical correlation analysis (CCA) and then simply averaging the rainfall forecasts; and ii) by combining the three models’ 850 hPa forecasts, and then downscaling them using CCA. Downscaling is performed onto the 0.5° × 0.5° resolution of the CRU rainfall data set south of 10° south over Africa. Forecast verification is performed using the relative operating characteristic (ROC) and the reliability diagram. The performance of the two multi-model combinations approaches are compared with the single-model downscaled forecasts and also with each other. It is shown that the multi-model forecasts outperform the single model forecasts, that the two multi-model schemes produce about equally skilful forecasts, and that the forecasts perform better during El Nino and La Nina seasons than during neutral years. DA - 2012-02 DB - ResearchSpace DP - CSIR KW - Southern Africa rainfall forecast KW - Seasonal forecasting KW - Climatology KW - Probabilistic rainfall forecast skill KW - El Nino-Southern Oscillation KW - ENSO LK - https://researchspace.csir.co.za PY - 2012 SM - 0899-8418 T1 - Multi-model forecast skill for mid-summer rainfall over southern Africa TI - Multi-model forecast skill for mid-summer rainfall over southern Africa UR - http://hdl.handle.net/10204/5701 ER -