A search for information on short-duration precipitation rates uncovered several sources of data, primarily for North America and Europe. However, the data available, especially for 1-min rainfall rates, are insufficient to permit direct calculation of precipitation-rate frequency distributions for all but a few locations in the world. Since these statistics are needed for a variety of applications, researchers developed models that can be used to estimate 1-min rainfall-rate distributions. Some require climatic data, while others divide the globe into regions, each of which is associated with a representative distribution. A survey of the available data and a comparison of models for determining short-duration precipitation rate distributions is presented, with particular emphasis on 1-min rates. (Author).

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.

The principal objective of this study is to provide simple analytical methods for recovering the frequency distributions of any short-term rainfall. The required data are the total rainfall for a given period of time and the actual duration of the rain in days, hours, or minutes for estimating daily, hourly, or instantaneous rainfall, respectively. Average annual hourly rainfall may be estimated at times as a function of mean annual temperature. Instantaneous rainfall is limited in this study to one-hour storms or rainy periods within storms. Two rainfall models are provided. The first, the general model, is based mainly on a particular skew distribution that was found previously to represent rainfall under very diverse conditions. This model recovers a considerable range of information for almost any rainfall occurrence. The second, or explicit, model is specific for a given average rain rate. The latter model may be utilized for situations not covered by the general model or as an alternate method. In contrast to certain of the earlier techniques, the above models (a) depend on viable rainfall mass distribution for the situation at hand and (b) determine short-term rainfall, first with respect to the percent frequency of the total duration of the rain and with respect to real time. The results yield reasonably accurate short-term rain rates for nearly 98 percent of the rain period. Keywords: Computer programs, Computer program listings, BASIC programming language.

A model for estimating 1-min rainfall rates at a location for which routine climatic data are available was used to produce this atlas. Even though data were available for 3631 locations, considerable subjectivity and smoothing of the analyses were required because of the low station-density outside of North America and Europe. Northern Hemisphere analyses of rainfall rates equalled or exceeded 0.01, 0.05, 0.10, 0.50, and 1.0 percent of the time are presented for four mid-season months. Analyses of the highest rainfall rates for the same frequencies of occurrence regardless of the month in which they occur and companion analyses of the month in which the highest rate occurs are also presented.

A model for estimating 1-min rainfall rates at a location for which routine climatic data are available was used to produce this atlas. Even though data were available for 483 locations, considerable subjectivity and smoothing of the analyses was required because of the low station-density in most areas. Southern Hemisphere analyses of rainfall rates equalled of exceeded 0.01, 0.05, 0.10, 0.50, and 1.0 percent of the time are presented for four mid-season months. Analyses of the highest rainfall rates for the same frequencies of occurrence regardless of the month in which they occur and companion analyses of the month in which the highest rate occurs are also presented. (Author).