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Baoqiang Xiang, Ming Zhao, Xianan Jiang, Shian-Jiann Lin, Tim Li, Xiouhua Fu, and Gabriel Vecchi

)] are equally important for a skillful MJO prediction ( Waliser 2006 ). In this study, initial conditions for atmosphere and ocean were obtained through a nudging technique toward the observations. The atmospheric nudging fields include winds, temperature, geopotential height, and surface pressure using the NCEP Global Forecast System (GFS) analysis data (6-hourly interval). The SST is nudged to the National Oceanic and Atmospheric Administration (NOAA) optimum interpolation ¼° daily SST analysis

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Samuel S. Bell, Savin S. Chand, Kevin J. Tory, and Christopher Turville

section 3a ). Altogether, seven TC basins are defined ( Fig. 1 ) and for cases where a TC crosses two basins, the first track point of that TC determines its basin. b. ERA-Interim ERA-Interim ( Dee et al. 2011 ) is a global atmospheric reanalysis product generated by the European Centre for Medium-Range Weather Forecasts (ECMWF) available at a variety of horizontal resolutions and a vertical resolution of 50 hPa in the lower troposphere. For this study, the required atmospheric data for the OWZ-D were

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Philippe P. Papin, Lance F. Bosart, and Ryan D. Torn

present a more detailed climatological view of PVS activity in the NATL basin, which incorporates previously neglected differences in their size, intensity, and tilt in order to investigate linkages to TC activity. To accomplish this goal, a new PVS algorithm is introduced that builds upon previous work used to identify RWB and PVS events. We will also apply this new PVS algorithm to three reanalysis datasets—ERA-Interim (ERAI), the Climate Forecast System Reanalysis (CFSR), and the Japan

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Prashant D. Sardeshmukh and Brant Liebmann

Medium-Range Weather Forecasts (ECMWF)in Reading, England. In particular, the authors' focus is on the change in the circulation between 1988 and1989 as estimated by these two sets of analyses, especially the change in the 200-mb wind divergence associatedwith organized deep convection. The authors find that in many regions the discrepancy between these estimatesis of the order of the change itself. A comparison with maps of the outgoing longwave radiation (OLR) is notquantitatively useful in this

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Gan Zhang, Hiroyuki Murakami, Xiaosong Yang, Kirsten L. Findell, Andrew T. Wittenberg, and Liwei Jia

activity, this study examines retrospective seasonal predictions (“hindcasts”) from a state-of-the-art operational model at GFDL and proposes an evaluation framework for coupled climate models. We use a “nudging” technique to relax model solutions toward specified observations of the climate system (e.g., the atmosphere or the ocean) while retaining relatively realistic interactions among model components. This technique helps to address the following research questions: How do errors in individual

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Amir Shabbar, Barrie Bonsal, and Madhav Khandekar

(1996) employed the canonical correlation analysis (CCA) technique to examine the skill of seasonal temperature and precipitation forecasts in Canada. Their leading CCA loading pattern for winter precipitation shows a dipole pattern that is very similar to the precipitation anomaly pattern shown in Fig. 3a (see their Fig. 18). They indicated that the warm phase of the SO plays a dominant role in these Canadian precipitation anomalies during winter. Figure 3b shows the precipitation pattern

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Carl Fortelius and Eero Holopainen

, where monthlyaverages over large land areas agree to within 10 W m-2. Elsewhere, differences of up to 60 W m-2 occur forcorresponding averages. Over low httitude continents, the residuals are generally too small over convectivelyactive regions and too large over subsidence regions. A reason for this may be known deficiencies in the radiationparameterizations of the forecast model used in the data assimilation. The distribution of latent heat sources, obtained from the circulation data, is

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Julien P. Nicolas and David H. Bromwich

) Climate Forecast System Reanalysis (CFSR; Saha et al. 2010 ). When evaluated in high southern latitudes, the three reanalyses have shown significantly greater reliability than earlier-generation reanalyses ( Bromwich et al. 2011 , 2013 ; Bracegirdle and Marshall 2012 ; Bracegirdle 2013 ; Screen and Simmonds 2012 ). This improvement comes mainly as a result of improved model physics, more advanced bias correction and data assimilation techniques, and higher horizontal and vertical model resolution

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Amir Shabbar and Walter Skinner

– Southern Oscillation (ENSO) phenomenon in the tropical Pacific Ocean (i.e., Cole and Cook 1998 ; Nigam et al. 1999 ; Trenberth and Barnstator 1992 ). The role of ENSO in the initiation of North American drought is further supported in a study by Rajagopalan et al. (2000) . Using partial correlation analysis and the singular value decomposition (SVD) technique, they identified the changing relationship between ENSO and the United States drought patterns during the twentieth century. By employing a

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Raúl E. López and Ronald L. Holle

satellite information and numerical model results. This has been accompanied in the1980s by advanced workstation techniques for the simultaneous display, analysis, and animation of different meteorological fields. This effort at improvementhas culminated in the vast modernization of the National Weather Service starting in the late 1980s andcontinuing into the present. In addition to producingbetter forecasts and warnings, the Weather Service hasincreased their efforts to disseminate these productsand

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