Research on Surface Map Analysis

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The goal of this project is to improve surface weather map analysis and, thus, short-term weather forecasting. Present practice by the operational meteorological community relies on the Norwegian Cyclone Model. Many of these analyses, however, demark fronts not associated with significant horizontal temperature contrast as required by the model. Many fronts identified in current analyses appear to be determined on the basis of a cyclonic wind shift. Such features are better denoted as baroclinic troughs with the associated clouds and precipitation that differ from those associated with actual fronts.The research will be based on study of episodes of real fronts selected from an existing archive. The synoptic circumstances for the formation, evolution and dissipation of fronts in these episodes will be documented. Frontogenetical calculations will be made. The results will be compared with each other and with the observed change in the temperature gradient on a series of maps for each episode.The PI also will begin a preliminary investigation into a pronounced and consistent diurnal change of wind direction at Tucson, Arizona - southeasterly at night and northwesterly during the daytime. This variation has been observed to be as consistent as land and sea breezes. This flow structure appears to be due to the differential horizontal surface characteristics between a small mountain range to the northwest of the city and a dry elevated plateau to the southeast. The physical processes responsible for this flow structure will be investigated. Successful completion of this research can potentially be of value to operational forecasters as well as finding its way into meteorological courses and text books.