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Paul Fox-Hughes

during the day. It is likely that the driest, high-momentum air was associated with the passage across Tasmania of a “dry band” ( Mills 2008 ) in the water vapor imagery. The 0426 UTC GOES WV image ( Fig. 7 ) shows the main frontal cloud band clearly visible as an area of white, and the clear space over Tasmania evident from the IR images is revealed as a significant, though narrow, dry band extending back across western Victoria to a broad region of very dry air aloft over the Great Australian Bight

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Thomas F. Lee, Susan Atwater, and Charles Samuels

scattering by ice results in a much smallerpolarization effect and smaller difference in brightnesstemperatures. In addition to sea ice, atmospheric factors such as water clouds, precipitation, water vapor,and surface wind stress can also produce low polarization differenc,es over water. Such signatures (such asclouds on Fig. 4d) sometimes mimic sea ice on 85.5GHz polarization difference images. However, mostanalysts who are already familiar with general ice coverage over a region will not mistake these

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David A. R. Kristovich and Neil F. Laird

1973 ; Chang and Braham 1991 ). The magnitudes of heat and moisture fluxes from the surface of the lakes greatly influence the growth rate of the convective boundary layer. These surface fluxes, in turn, are controlled largely by temperature and vapor pressure differences between the surface and overflowing air and low-level wind speeds. Satellite observations reveal the presence of complex spatial variations of wintertime surface water temperatures across each of the Great Lakes ( Schwab et al

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Qingyun Zhao, Thomas L. Black, and Michael E. Baldwin

the relative humidity at a point where cloud already exists drops below the critical value U 00 . All water vapor from evaporation is used to increase the relative humidity at this point. Evaporation will stop when U 00 is reached. Based on the above discussions, the evaporation equation for stratiform clouds is obtained by using the equation q = Uq s : where Δ t is the time step for the precipitation calculation. Since the large-scale precipitation is calculated at every four

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William H. Bauman III, Michael L. Kaplan, and Steven Businger

the 4 days investigated. However, it should be noted that the entire sounding should be examined closely by investigating multiple stability parameters in any convective situation. To infer more information about the water vapor distribution and static stability, vertical cross sections of relative humidity and equivalent potential temperature were produced. The cross sections are based on the combined observational and numerical model analysis grids constructed for this research. Each cross

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Kristen Kehrer, Brian Graf, and William P. Roeder

previous GPS PW lightning prediction model was not duplicated. However, the two new GPS PW models did show promise. 2. Introduction a. Description of GPS PW PW is traditionally calculated from data obtained by weather balloons. However, it was discovered over a decade ago that PW can be calculated from GPS satellites ( Bevis et al. 1992 , 1994 ). Previous researchers have called this the GPS integrated water vapor (GPS IWV), but the authors use the term precipitable water rather than IWV since the two

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Xiaodong Hong, Craig H. Bishop, Teddy Holt, and Larry O’Neill

1. Introduction The western North Pacific subtropical high (WNPSH) is one of the most difficult systems to forecast due to its nonlinear, complex, and highly variable characteristics. It is an important weather system for East Asia since the variation of its zonal position can greatly influence the transport of water vapor along its northwestern edge and the resultant rainfall ( Zhou and Yu 2005 ; Yang and Sun 2005 ). The WNPSH’s movement in the north–south direction is also strongly related

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Kenneth D. Lapenta, Barbara J. McNaught, Steven J. Capriola, Louis A. Giordano, Charles D. Little, Stephen D. Hrebenach, Gary M. Carter, Mario D. Valverde, and Derek S. Frey

south serve as sources of low-level moisture. Middleto upper-level moisture can be transported northwardfrom the Tropics. This often can be seen as a plumein the water vapor satellite imagery (6.7 t~m). It mustbe pointed out that the presence of the middle- toupper-level plume is not necessary for heavy rain, because moisture at those levels makes only a relativelysmall contribution to the precipitable water. Intenseconvection can develop within the "dry slot" zonesshown in the water vapor imagery

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Andrew W. Ellis and Daniel J. Leathers

conditions common in winter, including freeze–thaw cycles and a full range of precipitation types. The transport of liquid water and water vapor is included in the model for use in the heat balance equations. The governing equations for heat and mass balance are applied to horizontally infinite control volumes in order to obtain a numerical solution of the temperature profile of the snow pack. The boundary conditions for the model are determined by the meteorological conditions at the air

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Douglas K. Miller, David Hotz, Jessica Winton, and Lukas Stewart

extreme rainfall, particularly when the fast-flowing maritime tropical ARs encounter topography. Initial work focused on identifying ARs using satellite-observed estimates of integrated water vapor (IWV), locating IWV plume values of at least 2 cm, greater than 2000 km in length, and narrower than 1000 km in width ( Ralph et al. 2004 ). Examination of numerous swaths of passive microwave imagers showed that anomalously high composite IWV plumes intersecting the West Coast were often collocated with

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