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David A. Short, James E. Sardonia, Winifred C. Lambert, and Mark M. Wheeler

, westerly shear being correlated with severe weather ( Hagemeyer and Schmocker 1991 ). Easterly shear can also result in high-level anvil clouds over the space launch and landing facilities of the John F. Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) on Florida's east coast, originating from convective systems over the Atlantic Ocean. Caniaux et al. (1994) used the term “forward anvil clouds” to describe the westward-propagating anvil of a tropical squall line in easterly

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Thomas M. Hamill, Robert P. D'Entremont, and James T. Buntin

February 1991, in final form 6 February 1992) The Air Force Global Weather Central (AFGWC) Real-Time Nephanalysis (RTNEPH) is an automatedcloud model that produces a 48-kin gridded analysis of cloud amount, cloud type, and cloud height. Its primaryinput is imagery from polar-orbiting satellites. Six main programs make up the RTNEPH. These are the satellite data mapper, the surface temperatureanalysis and forecast model, the satellite data processor, the conventional data processor, the merge

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Robert P. d’Entremont, Richard Lynch, Gennadi Uymin, Jean-Luc Moncet, Ryan B. Aschbrenner, Mark Conner, and Gary B. Gustafson

thresholds are adapted to pixel-specific atmospheric, earth surface, and view-illumination geometry conditions using cloud-free radiative transfer model simulations. Statistical techniques are also used in cloud detection models to estimate the radiative characteristics of the clear state. Lyapustin et al. (2008) present a spatial-context approach to prescribing baseline clear-sky conditions using a time series of multispectral MODIS cloud-cleared radiance observations. The U.S. Air Force (USAF) 557th

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Greg L. Dial, Jonathan P. Racy, and Richard L. Thompson

remain within the zone of linear forcing. The cloud-layer shear vector was parallel to the dryline. A zone of low-level convergence of (8–12) × 10 −5 s −1 was evident along the dryline, which appeared to be enhanced by the downward mixing of southwesterly momentum west of the moist axis. These values are in a range that would tend to promote an evolution to a linear or mixed mode. In this case, a small normal component of the mean cloud-layer wind with respect to the dryline allowed the storms to

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Paul J. Roebber, James M. Frederick, and Thomas P. DeFelice

in Fig. 14b ) and the cold, dry advection in its wake led to a short-lived lifting of the cloud ceiling ( Figs. 8 and 11 ). The effects of temperature advection were important in this period, as evidenced by PBL simulations with and without implied temperature changes. In the former case, the modeled sounding was drier and cloud ceilings were elevated compared to the run with no temperature advection. Thus, the early period was quite sensitive to forcing from synoptic-scale systems: a strong

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Rita D. Roberts and Steven Rutledge

1. Introduction This study shows how Geostationary Operational Environmental Satellite (GOES) imagery and Weather Surveillance Radar-1988 Doppler (WSR-88D) data can be used by a forecaster to monitor the development of cumulus clouds into vigorous convective storms and how this process of monitoring cloud growth can be automated to produce additional lead time on convective storm nowcasting. Vigorous convective storms are defined here as precipitating cumulus congestus and cumulonimbus clouds

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Conrad L. Ziegler and Erik N. Rasmussen

limit warming and drying of the parcel, which in turn would limit increases of the LCL and LFC values for the parcel following the motion. 9 In the event that mesoscale lifting was sufficient to achieve parcel saturation, thus forming a cumulus cloud, but insufficiently deep to lift the air parcel through its LFC, mixing and its effect on parcel buoyancy forcing would become important. Inspection of the individual adiabatic cumulus cloud profiles ( Figs. 3b , 8b,c , and 13b ) suggests the

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David J. Stensrud, Geoffrey S. Manikin, Eric Rogers, and Kenneth E. Mitchell

evolution is the cold pool, a pool of evaporatively cooled downdraft air that spreads out horizontally along the ground beneath a precipitating cloud. Cold pools are important because some of the environmental air approaching the cold pool likely will be lifted up and over it, and this lifting process is important to the development of new convection ( Byers and Braham 1949 ; Wilson and Schreiber 1986 ). Case studies of the influences of mesoscale-sized cold pools (100–400 km in horizontal extent) on

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Peter M. Caplan and Glenn H. White

significant changes in the last few years, resulting in considerable improvement in the skill of itsforecasts. The introduction of interactive clouds in late 1988 significantly reduced a cold bias present in modelforecasts since April 1985. Model errors during recent Northern Hemisphere summers appear linked to thermalforcing, causing temperatures and upper tropospheric heights over cooler ocean areas to be too low, and heightsover the western United States to be too high.1. Introduction The National

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Patrick S. Market, Ronald W. Przybylinski, and Scott M. Rochette

the final manuscript. REFERENCES Anthes, R. A. , 1977 : A cumulus parameterization scheme utilizing a one-dimensional cloud model. Mon. Wea. Rev , 105 , 270 – 286 . 10.1175/1520-0493(1977)105<0270:ACPSUA>2.0.CO;2 AWS , 1979 : The use of the skew T, log P diagram in analysis and forecasting (revised 1995). Air Weather Service Rep. AWS/TR-79/006, Air Weather Service, Scott Air Force Base, IL, 164 pp . Benoit, R. , Côté J. , and Mailhot J. , 1989 : Inclusion of a TKE boundary layer

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