A Comparison Of Model Performance Between The Nested Grid And Eta Models

A Comparison of Model Performance Between the Nested Grid and Eta Models

Assessment of the performance of the National Meteorological Center's (NMC) new Eta numerical weather prediction model requires objective evaluation through direct comparison of model forecast output to its own analysis and to the analysis of other numerical models. The ultimate goal of the Eta Model is to provide accurate mesoscale weather forecasts through the late 1990's which are superior to those currently provided by the older NGM. To accurately evaluate the Eta Model, several model forecast output fields were compared to the NGM for a common population of extratropical cyclones over a period of five months. The separate model forecasts were also evaluated against their own analysis. Selected fields included central sea level pressure. 12h central pressure change 1000-500 mb thickness at the cyclone center, and both convective and total precipitation at the cyclone center. Results indicated a consistent negative bias in forecast central pressure values for the NGM. and a positive bias for the Eta Model. Mean forecast position errors were nearly identical for both models through 36h with the Eta forecast position errors only slightly larger at 48h. Both models exhibited a slight cold bias in 1000-500 mb thickness fields at the cyclone centers with the NGM being greater. The Eta Model tended to forecast more precipitation in general and in particular the precipitation was higher for stable precipitation.

Compilation of Theses Abstracts, October 1994-September 1995

Masters Theses in the Pure and Applied Sciences

Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this jOint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 40 (thesis year 1995) a total of 10,746 thesis titles from 19 Canadian and 144 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 40 reports theses submitted in 1995, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.