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Samantha L. Lynch and Russ S. Schumacher

) and Mullen and Buizza (2001) also found that the accuracy in precipitation forecasts decreases as the rainfall threshold increases. Hakim and Torn (2008) introduced the technique of ensemble synoptic analysis for an extratropical cyclone, finding the relationships between different synoptic features by computing statistical operators such as covariances and correlations within an ensemble of forecasts. Similarly, Torn (2010) used this method to examine the dynamical mechanisms that led to

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Manuel Gebetsberger, Jakob W. Messner, Georg J. Mayr, and Achim Zeileis

, and G. Brunet , 2015 : The quiet revolution of numerical weather prediction . Nature , 525 , 47 – 55 , doi: 10.1038/nature14956 . 10.1038/nature14956 Ben Bouallègue , Z. , and S. E. Theis , 2014 : Spatial techniques applied to precipitation ensemble forecasts: From verification results to probabilistic products . Meteor. Appl. , 21 , 922 – 929 , doi: 10.1002/met.1435 . 10.1002/met.1435 Bentzien , S. , and P. Friederichs , 2012 : Generating and calibrating probabilistic

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Gui-Ying Yang, Samantha Ferrett, Steve Woolnough, John Methven, and Chris Holloway

current analyses and forecasts. The methodology is used to identify horizontal winds, geopotential height and hence divergence and vorticity structures associated with distinct equatorial wave types. This paper is organized as follows. Section 2 details the data used, briefly introduces the equatorial wave theory that is the basis for the diagnostic technique, and describes the spatial projection methodology used to identify equatorial waves. Section 3 presents the new time-window technique

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Weihong Qian, Ning Jiang, and Jun Du

,” “no meteorological evidence is presented for why areas of moist vorticity and moist divergence should overlap with regions of 24-h accumulated rainfall,” and “all three quantities have not been verified against the output of precipitation directly from the model nor is the approach of combining meteorological quantities into a single parameter appropriate in an ingredients-based forecasting approach.” The first two points concern scientific justification mathematically and meteorologically, while

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J. Brotzge and S. Erickson

associated NWS warning; a list of those tornadoes without advance NWS warning was also provided. These reports contained the date and location of each tornado, the time of the event, the time the NWS warning was issued, the weather forecast office (WFO) that issued the warning, the county or parish location, the estimated F-scale rating, the number of fatalities and estimates of the damage. Additional information on each zero and negative lead-time event was obtained from the National Climatic Data

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Xingqin Fang and Ying-Hwa Kuo

produce excessive rainfall at the southern tip of the CMR (see Fang et al. 2011 ). Although the exact reason for this rainfall overprediction bias is still not clear, such a topographically locked rainfall bias will be amplified by the probability-matching technique. In this paper, we develop a modified probability-matching technique for ensemble forecasting of the topography-enhanced typhoon heavy rainfall over Taiwan. The basic idea is to collect the track and rainfall forecasts from a large

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Yong Wang, Martin Bellus, Jean-Francois Geleyn, Xulin Ma, Weihong Tian, and Florian Weidle

1. Introduction Ensemble prediction techniques have been applied in most numerical weather prediction (NWP) centers as a dynamical way of accounting for the forecast uncertainty. The optimal design of an ensemble prediction system (EPS) strongly depends on the quantification of uncertainties due to errors in initial conditions (ICs), model formulation, and physical parameterizations. Additional challenges posed for a skillful regional EPS include, for example, the problem of quantifying the

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Joshua M. Boustead, Barbara E. Mayes, William Gargan, Jared L. Leighton, George Phillips, and Philip N. Schumacher

Wilhelmson R. B. , 1994 : The role of midtropospheric winds in the evolution and maintenance of low-level mesocyclones . Mon. Wea. Rev. , 122 , 126 – 136 . Bunkers, M. J. , 2002 : Vertical wind shear associated with left-moving supercells . Wea. Forecasting , 17 , 845 – 855 . Bunkers, M. J. , Klimowski B. A. , Zeitler J. W. , Thompson R. L. , and Weisman M. L. , 2000 : Predicting supercell motion using a new hodograph technique . Wea. Forecasting , 15 , 61 – 79 . Bunkers, M. J

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Stefano Alessandrini, Simone Sperati, and Luca Delle Monache

1. Introduction The analog ensemble (AnEn) technique has been recently used to generate probabilistic predictions of 10-m wind speed and 2-m temperature ( Delle Monache et al. 2013 , hereafter DM13 ) starting from a deterministic meteorological forecast. The theoretical basis for the analog approach was provided by Hamill and Whitaker (2006) who used it to calibrate probabilistic predictions of 24-h accumulated precipitation from a numerical weather prediction (NWP) ensemble. The AnEn uses a

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Debra M. Ford, Russell L. Elsberry, Patrick A. Harr, and Paul H. Dobos

MAY 1993 FORD ET AL. 1279Forecasting Tropical Cyclone Recurvature. Part II: An Objective Technique Using an Empirical Orthogonal Function Representation of Vorticity FieldsDEBRA M. FORD,* RUSSELL L. ELSBERRY, PATRICK A. HARR, AND PAUL H. DOBOSDepartment of Meteorology, Naval Postgraduate School, Monterey, California(Manuscript received 9 March 1992, in final form 13 October 1992

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