Marine fog forecasts during the summer period in the North Pacific are not made presently with any acceptable degree of accuracy. Objective fog development models exist and are used with some success for localized coastal regions of the western U.S.; scarcity of accurate data has hindered creation of a reliable open-ocean model. The Eulerian single-station approach, utilizing a segment of the complete accurate data of Ocean Weather Station Papa (50N, 145W) is applied in this study to an objective marine fog forecasting model. The time-series study of significant atmospheric variables at OWS Papa, when coupled with a chronological synoptic overview, delineates accurately fog/no fog sequences in the summer months of 1973 and 1977. Actual observed fog situations are evaluated by the general model and presented in relation to open-ocean fog indices, NOAA 5 satellite coverage and synoptic history. The open-ocean forecast model is tested on an independent data set for the month of July 1975 at OWS Papa, with favorable results. The research delineates four required indices that must all be positive to forecast fog. These indices, when plotted daily in the region of OWS Papa allow a single station to predict, with some confidence out to twenty-four hours, the occurrence of advection fog. (Author).

This volume presents the history of marine fog research and applications, and discusses the physical processes leading to fog's formation, evolution, and dissipation. A special emphasis is on the challenges and advancements of fog observation and modeling as well as on efforts toward operational fog forecasting and linkages and feedbacks between marine fog and the environment.

The feasibility of the use of Geosat altimeter-derived wind speed and significant wave height data for operational applications is investigated. Geosat wind and wave data are compared with buoy observations for a 17 month period to determine the error characteristics as a function of various data acceptance time windows and spatial separation distances between the colocated data points. The results show that Geosat wind speed errors are sensitive to the time acceptance windows and less so to spatial separation distances, whereas Geosat wave height errors are not so sensitive to spatial and temporal separations. Three days of Geosat wind speeds and two periods of near real time Geosat significant wave height data are assimilated into the NMC's operational weather and wave forecast models. The results show that inclusion of Geosat wind speed data leads to a small impact in the southern Hemisphere, and virtually no impact in the northern Hemisphere. The Geosat significant wave height data, on the other hand, are found to have a positive impact and are extremely beneficial in short range wave forecasts over the global oceans.

This report describes the OPC spectral wave forecasting model for the Columbia River Bar, as well as the results of some numerical experiments, on both micro and main frame computers. The model, essentially, calculates the transformation of offshore wave spectra forecasted by the OPC global wave model due to the combined effects of bottom topography and tidal currents in the vicinity of the Columbia River entrance.