J. H. Keller, S. C. Jones, J. L. Evans, and P. A. Harr
Geophysical Research Letters (1 June 2011)
The characteristics of the extratropical transition (ET) of tropical cyclones and its impact on the midlatitude flow are examined in the THORPEX Interactive Grand Global Ensemble (TIGGE) multimodel ensemble prediction system (EPS). Ten ensemble forecasts initialized prior to ET for five tropical cyclones in 2008 are investigated using an empirical orthogonal function analysis and fuzzy clustering methodology. Each forecast contains 231 members from eight different global EPS. The EPS contributing to TIGGE differ in their spread and their contributions to the different scenarios. Some of the individual EPS are generally confined to only a few scenarios, whereas others contribute regularly to almost all. TIGGE contains more development scenarios than European Centre for Medium Range Weather Forecast (ECMWF) EPS but the full range of development scenarios is only found with the ECMWF included in the multimodel EPS.
keywords: TIGGE; ensemble forecasts; extratropical transition; tropical cyclones; 3235 Persistence, memory, correlations, clustering; 3245 Probabilistic forecasting; 3364 Synoptic-scale meteorology; 3372 Tropical cyclones; 4315 Monitoring, forecasting, prediction