An unusual Saharan dust outbreak into central Europe and heavy precipitation at the southern side of the Alps in May 2008: A TIGGE case study Lars Wiegand 1,2 , Arwen Twitchett 2 , Conny Schwierz 3 & Peter Knippertz 2 Third THORPEX International Science Symposium, Monterey: 14-18 Sept. 2009 1 2 3
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Lars Wiegand 1,2 , Arwen Twitchett 2 , Conny Schwierz 3 & Peter Knippertz 2
Third THORPEX International Science Symposium, Monterey: 14-18 Sept. 2009. An unusual Saharan dust outbreak into central Europe and heavy precipitation at the southern side of the Alps in May 2008: A TIGGE case study. Lars Wiegand 1,2 , Arwen Twitchett 2 , Conny Schwierz 3 & Peter Knippertz 2. - PowerPoint PPT Presentation
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An unusual Saharan dust outbreak into central Europe and heavy
precipitation at the southern side of the Alps in May 2008:A TIGGE case study
Lars Wiegand1,2, Arwen Twitchett2, Conny Schwierz3 & Peter Knippertz2
Third THORPEX International Science Symposium, Monterey: 14-18 Sept. 2009
1 2 3
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
Outline
Motivation
Upper-Level Development RMSE/SPREAD
analysis errors
position of forecasted streamers
High Impact Weather Saharan dust storm
heavy precipitation in Southern Switzerland
Conclusions
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
Motivation
2008/05/27 10UTC 2008/05/27 13UTC
article in newspaper „Süddeutsche“ 2008/05/29: „Die Sahara über Deutschland“
Gornergletscher 08/2008, dust from 05/2008
albedo increase ablation increase mass balance decrease
Motivation
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
Motivation
widespread heavy precipitation caused: flooding on the Alpine south side of Switzerland and Italy
Lake Maggiore rised by 10 cm in just 24 hours
Motivation
4-day sumof precipitation
(26th – 29th of May 2008)
mm
data: ENSEMBLE (gridded data set from rain gauges)
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
Analysis End of May 2008 (21st-26th)
Upper-Level Development
upper level PV
operational analysis ECMWF
region of interest (29-55N, 15W-2E)
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
RMSE of all models (Box: 29-55N, 15W-2E)
ECMWF_europe
BoM_australia
CMA_china
CMC_canada
CPTEC_brazil
JMA_japan
KMA_korea
NCEP_usa
UKMO_uk
RMSE calculated with Analysis from ECMWF
RMSE calculated with every Centers own Analysis
Upper-Level Development
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
0,22
(USA,
Interpolation)
0,44
(Korea,
3Dvar)
0,59
(China,
Interpolation)
0,23
(Brazil,
USA Interpolation)
0,26
(Japan,
4Dvar)
0,41
(Australia,
Interpolation)
0,23
(UK,
4Dvar)
0,25
(Canada,
4Dvar)
RMSE in box
-0.5 1.0 1.5-1.0-1.5 0.5
Upper-Level Development
(4Dvar)
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion
“non-dispersive”
CMA_china
CMC_canada
ECMWF_europe
JMA_japan
RMSE & SPREAD
RMSE
SPREAD
(slightly) overdispersiveunderdispersive
BoM_australia
CPTEC_brazil
NCEP_usa
UKMO_uk
KMA_korea
Upper-Level Development
Third THORPEX International Science Symposium, Monterey: 14-18 September 2009
Motivation Upper-Level Development High Impact Weather Conclusion