Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Map of mean diurnal (12-hourly) and median (midway between 0000 and 1200 GMT) monthly height changes at the 850-, 700-, and 500-mb levels over North America and vicinity from January through December are presented, using grid-point data from an earlier study. The height changes were objectively derived and analyzed by computer. The use of these charts as an aid to weather forecasting is briefly described

The mean maps show average geopotential metric heights for the 850-, 700-, 500-, and 300-mb pressure surfaces at 000 and 1200 GMT for each month of the year. The maps were derived by computer from objectively analyzed grid-point data for November 1961 through January 1969. The use of these maps is briefly described to obtain the average monthly height for any day and 12-hour period