Wiegand, L, Twitchett, A, Schwierz, C et al. (1 more author) (2011) Heavy Precipitation at the Alpine South Side and Saharan Dust over Central Europe: A Predictability Study Using TIGGE. Weather and Forecasting, 26 (6). 957 - 974. ISSN 0882-8156
Abstract
Around 26 May 2008 a pronounced potential vorticity (PV) streamer penetrated from the North Atlantic into the western Mediterranean Sea followed by widespread dust mobilization over the Maghreb region of northwest Africa and a subsequent northward transport into central Europe. At the same time, strong southerly flow over the Mediterranean Sea caused heavy precipitation and flooding at the windward side of the European Alps. Using continuous and feature-based error measures, as well as ensemble correlation techniques, this study investigates the forecast quality and predictability of synoptic and mesoscale aspects of this high-impact event in operational ensemble predictions from nine meteorological centers participating in The Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) project. TIGGE is a recently established program providing ensemble forecasts in a standardized format, which allows for an exciting new multimodel approach to investigating the predictability of, for example, high-impact weather and its dynamics. The main conclusions from this study are that 1) the quality of the PV streamer forecasts degrades with lead time showing a general tendency toward too weak Rossby wave; 2) when focusing on the region around the streamer, most models show root-meansquare errors of the same magnitude or larger than the ensemble spread (underdispersive behavior); 3) errors are reduced by about 50% if the comparison is made to each center's own analysis instead of the ECMWF analysis; 4) peak wind speeds over the Sahara tend to be underpredicted, with differences in model formulation dominating over differences in the representation of the PV streamer; and 5) ensemble-mean multimodel forecasts of 4-day accumulated precipitation appear accurate enough for a successful severe-weather warning.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Copyright 2011 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org. |
Keywords: | Ensembles; Extreme events; Numerical weather prediction/forecasting; Precipitation; Rossby waves; Wind |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Oct 2013 11:58 |
Last Modified: | 29 Mar 2018 16:29 |
Published Version: | http://dx.doi.org/10.1175/WAF-D-10-05060.1 |
Status: | Published |
Publisher: | American Meteorological Society |
Identification Number: | 10.1175/WAF-D-10-05060.1 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76602 |