The White Oak Institute

A participant-observer discovers the elements that help a fifth-grader overcome his writer's block: a nurturing classroom environment and a teacher/student relationship founded on encouragement and expectations of success. With affirmation, the child's self-belief begins to grow, and he starts to achieve in writing.

A heavy rainstorm over Kentucky, producing extensive flooding, was concentrated in a narrow band oriented nearly zonally just south of the Ohio River. Analysis of routine surface observations showed that an intense quasi-stationary surface front formed during the 24-h period of heaviest rainfall. This front was parallel to the rainband and was some distance to the south of it. Horizontal temperature gradients reached more than 20°F over 110 km. Analysis of sea level pressure showed that geostrophic deformation was present in a small region ahead of each of two small centers of low pressure that migrated eastward along the front. Vertical cross sections normal to the front showed that conditional upright and symmetric stabilities were small or negative in the frontal updraft. It was inferred from this that the frontal updraft was unusually intense and narrow, qualitatively consistent with the intensity of the rainband.

The impact of initial condition uncertainty (ICU) on quantitative precipitation forecasts (QPFs) is examined for a case of explosive cyclogenesis that occurred over the contiguous United States and produced widespread, substantial rainfall. The Pennsylvania State University‐National Center for Atmospheric Research (NCAR) Mesoscale Model Version 4 (MM4), a limited-area model, is run at 80-km horizontal resolution and 15 layers to produce a 25-member, 36-h forecast ensemble. Lateral boundary conditions for MM4 are provided by ensemble forecasts from a global spectral model, the NCAR Community Climate Model Version 1 (CCM1). The initial perturbations of the ensemble members possess a magnitude and spatial decomposition that closely match estimates of global analysis error, but they are not dynamically conditioned. Results for the 80-km ensemble forecast are compared to forecasts from the then operational Nested Grid Model (NGM), a single 40-km/15layer MM4 forecast, a single 80-km/29-layer MM4 forecast, and a second 25-member MM4 ensemble based on a different cumulus parameterization and slightly different unperturbed initial conditions. Large sensitivity to ICU marks ensemble QPF. Extrema in 6-h accumulations at individual grid points vary by as much as 3.000. Ensemble averaging reduces the root-mean-square error (rmse) for QPF. Nearly 90% of the improvement is obtainable using ensemble sizes as small as 8‐10. Ensemble averaging can adversely affect the bias and equitable threat scores, however, because of its smoothing nature. Probabilistic forecasts for five mutually exclusive, completely exhaustive categories are found to be skillful relative to a climatological forecast. Ensemble sizes of approximately 10 can account for 90% of improvement in categorical forecasts relative to that for the average of individual forecasts. The improvements due to short-range ensemble forecasting (SREF) techniques exceed any due to doubling the resolution, and the error growth due to ICU greatly exceeds that due to different resolutions. If the authors’ results are representative, they indicate that SREF can now provide useful QPF guidance and increase the accuracy of QPF when used with current analysis‐forecast systems.

Share Icon Share Twitter Facebook Reddit LinkedIn Reprints and Permissions Cite Icon Cite Search Site Citation John F. Waymouth; Divert SSC Funds to Physics at NSF …. Physics Today 1 July 1991; 44 (7): 84. https://doi.org/10.1063/1.2810190 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentPhysics Today Search Advanced Search

Although the single-parent family is becoming a predominant family structure, there is a surprising scarcity of articles discussing its typical problems or detailing specific therapeutic approaches. This paper attempts, first, to list some core problems encountered by all single parents and, second, to present a sequence of therapeutic approaches geared toward dealing with these problems. Structural theory, with its emphasis on subsystems, generational boundaries, and organizational patterns, provides a framework for viewing the built-in vulnerabilities of the single-parent family unit. Minuchin's (3) emphasis on generational boundaries and the problem of enmeshment underlies the theoretical and therapeutic approach presented here. I have drawn heavily on Haley's (2) idea that the therapist must be an authority, a problem-solver, and a teacher. Finally, the emphasis on creating new organizational patterns is most thoroughly explored in Aponte's (1) discussions of "underorganized families" (many of whom are single-parent families).