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<br />model these components individually. We, therefore, adapt the methodology of <br />Schickedanz (1974) and use, for the purpose of this analysis, the surface <br />raincell which he states is the smallest definable rain producing entity of a <br />storm and shows that it generally reflects conditions within the convective <br />cells aloft. Schickedanz (1974) defined a raincell in the following manner: <br />"A raincell in a multicellular system is a closed isohyetal entity within the <br />overall enveloping isohyet of a rain-producing system; that is, it describes <br />an isolated area of significantly greater intensity than the system-enveloping <br />i sohyetal. When raince 11 s deve 1 op apart from a mult ice" ul ar storm system, <br />the system-enveloping isohyet will not be present, and the singll~ cell is <br />uniquely defined by the separation between rain and no rain." Hl~ defined a <br />storm as an entity of rain, one or more raincells and/or areas of rain, that <br />can be identified with a specific synoptic weather classification and is <br />separated from other entities by 20 mi and/or one hour between rain end <br />and start times. According to these definitions, it can be seen from Fig. 1 <br />that the illustrated storm is composed of three raincells. <br /> <br />The present analysis of the sampling variance of raingage networks will be <br />based on the raincell. The gage density that is required to quantitatively <br />resolve the smallest size raincell that contributes meaningfully to the total <br />storm rainfall also determines the upper bound of gage density (densest) that <br />is required to resolve the entire storm with at least the same accuracy. <br /> <br />Local random variabil ity may also contribute to the sampl ing varjiance of <br />raingage networks. Storm and lraincell isohyets are generally drawn fairly <br />smoothly by precipitation data analysts. However, if isohyets were drawn to <br />rigorously fit the point rainfall data, they would be quite irregular. How <br />much of this irregularity is due to measurement-related en"ors (e.g., evapora- <br /> <br />3 <br />