36 for the months of July, August, September, and October 1957. Daily 100-mb and 50-mb charts for the months of July, 1957 to November, 1957, inclusive, have been plotted with approximately 80% of all the data which eventually will become available. Graphical aids such as solar radiation correction curves, anticyclonic instability shear criteria, and geostrophic wind scales have been prepared to aid in the analysis of charts. Preliminary analyses for portions of 100-mb charts for the months of July, August, and September 1957 have been sketched. A study is being made to determine whether the thickness technique can be utilized in the analysis of 50-mb charts. Two short series of 100-mb charts over the Eurasian area for several days in July, 1957 and January, 1958 were prepared upon special request. Another short series of four hemispheric 100-mb charts for the period of November 16-19th, 1957, inclusive, were plotted and analyzed for use in connection with an experiment in numerical computer analysis of 100-mb charts, currently being undertaken in cooperation with the JNWP Unit at Suitland. The Navy Weather Research Facility supported a pilot study in coordination with this Project, Pennsylvania State University, and NWRC at Asheville to develop regression equations suitable for the extrapolation of data to the 100-, 50-, and 30-mb levels. The results of this pilot project were recently evaluated, and the full-scale development of suitable regression equations is now in process at Asheville. The equations will eliminate several months of work in developing scattergrams for the re- maining months of the year.

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