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F. M. Ralph, T. Coleman, P. J. Neiman, R. J. Zamora, and M. D. Dettinger

conducted, nor has the modulating role of precursor soil moisture on streamflow in AR events been documented. Because ARs usually move across a given location in less than a day and because it is winds at roughly 1 km above ground that are critical to identifying AR conditions ( Ralph et al. 2006 ), neither the standard surface observing network nor the standard 12-hourly upper-air balloon sounding network is capable of monitoring the onset and cessation of AR conditions. Hourly observations aloft are

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Youcun Qi, Jian Zhang, Brian Kaney, Carrie Langston, and Kenneth Howard

layer of air arises over a mountain barrier, precipitation amounts tend to increase sharply along the windward slope of the mountain ( Hill 1881 ; Henry 1902 , 1919 ; Peck and Brown 1962 ; Kitchen et al. 1994 ; Frei and Schär 1998 ; Houze and Medina 2005 ; Houze 2012 ). The increase in precipitation intensities at the lower slopes of mountains often seems surprisingly sharp because condensed moisture requires time to accumulate on particles and make them heavy enough to fall out. As pointed

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Masamichi Ohba, Shinji Kadokura, Yoshikatsu Yoshida, Daisuke Nohara, and Yasushi Toyoda

) for the baiu front suggest that advection of an equivalent potential temperature that consists of a poleward moisture flux by the low-level jet and cold air advection by the upper-level jet are important to the active baiu rainband. In addition, Yoshikane et al. (2001) reported that the baiu rainband is quite sensitive to not only the low-level jet, but also the positions (and meandering) of the upper-level jet stream, which is significantly influenced by 200-hPa GH. The analyses are conducted

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Sandra E. Yuter, David A. Stark, Justin A. Crouch, M. Jordan Payne, and Brian A. Colle

precipitation proportional to the combination of terrain slope, cross-barrier flow, and column-integrated moisture with modifications by advective processes and wave dynamics. Smith et al. (2005) used this model to reproduce the east–west pattern of precipitation gradients across Oregon. Hughes et al. (2009) found that such linear models agree closely with observations for unblocked flow but degrade in performance for blocked-flow cases. The enhancement of precipitation above or near local peaks in

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H. Leijnse, R. Uijlenhoet, C. Z. van de Beek, A. Overeem, T. Otto, C. M. H. Unal, Y. Dufournet, H. W. J. Russchenberg, J. Figueras i Ventura, H. Klein Baltink, and I. Holleman

, and soil moisture) of the catchment around the CESAR site are also available (see Brauer et al. 2009 ). The availability of these other atmospheric and hydrological data means that precipitation can easily be linked to other atmospheric and hydrological processes. The CESAR site is a regular host to large measurement campaigns (see, e.g., Crewell et al. 2004 ; Su et al. 2009 ; Kulmala et al. 2009 ), which occasionally bring many additional instruments to the site. The instruments at the CESAR

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James A. Smith, Gabriele Villarini, and Mary Lynn Baeck

). Extratropical systems during the fall, which can produce comparable rainfall to winter–spring systems, are much less important as flood agents in the eastern United States ( Fig. 1c ) because of the climatological minimum in antecedent soil moisture. We use October–November peaks (that are not tropical cyclones) as a surrogate for fall extratropical flood peaks. October–November flood peaks, that are not tropical cyclone events, account for less than 15% of annual flood peaks throughout the eastern United

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Dusanka Zupanski, Sara Q. Zhang, Milija Zupanski, Arthur Y. Hou, and Samson H. Cheung

, such as realistic and well-tuned error statistics, unbiased model forecasts, and observations; and the ultimate validations need to be done with independent observations and statistical verifications in atmospheric states such as precipitation, moisture, temperature, and dynamical variables in longer periods and broader ranges of conditions. Nevertheless, within the limit of a case study, we will examine how the assimilation of precipitation radiance influences the short-term (3 h) forecasts, and

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F. M. Ralph, E. Sukovich, D. Reynolds, M. Dettinger, S. Weagle, W. Clark, and P. J. Neiman

model microphysics are also important and can be amplified by mountains; for example, if the microphysics packages cause too much rain out in one place, then the downwind mountains will have less moisture or vice versa ( Colle et al. 1999 ). Partly to determine if the difference between the number of extreme events was an outlier (i.e., would the Pacific Northwest states normally have more extreme precipitation events), COOP daily precipitation totals were examined going back decades at roughly 400

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Jonathan J. Gourley, Scott E. Giangrande, Yang Hong, Zachary L. Flamig, Terry Schuur, and Jasper A. Vrugt

-RDHM The model concepts used in this study originate from the Sacramento model ( Burnash et al. 1973 ). This model was subdivided into grid cells having 4.76-km resolution, in accordance with the NWS Hydrologic Rainfall Analysis Project (HRAP) grid. Each grid cell has a water balance component as well as kinematic overland and channel routing components ( Koren et al. 2004 ). The water balance component of the model, referred to as the Sacramento Soil Moisture Accounting model (SAC-SMA), considers

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