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

Many operational features of the WSR-88D were incorporated specifically to aid forecasters in the detection of severe local storms (damaging winds, large hail, and tornadoes). One interpretive product, the Severe Weather Potential (SWP) algorithm, yields an index proportional to the probability that an individual thunderstorm cell will soon produce any severe weather phenomena. The SWP is based solely on radar information, namely vertically-integrated liquid VIL and storm horizontal extent.

The moisture model used for the Local AFOS MOS Program (LAMP) is described in this paper. The model predicts the degree of saturation in the single layer between 1000 and 500 mb by a moisture parameter known as the saturation deficit. Moisture is advected under the assumption that no evaporation or condensation occurs along the trajectory. The thickness and elevation of the advected air column determine the degree of saturation. Precipitation is forecast when the air column is saturated.