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<br />site-specific PMP. The addition of climatic extremes to assist in the <br />determination of atmospheric structures present during extreme precipitation <br />events is fundamentally sound. This process can be used to provide guidance <br />in deciding the use of appropriate PWI values for PMP calculations and 1'01' <br />determining adjustments to rainfall potential fOI' high elevation sites. <br /> <br />6.0 Comparison of HMR 55A and HMS site.spe!cific PMP callculatiol1s <br /> <br />The comparison of the local and general storm PMPs presented in this Section <br />is intended to point out the importance of selecting an appropriate methodology <br />and set of historic storms. Table 10 below summarizes the following local storm <br />PMP's discussed in this study: <br /> <br />1. HMR Plate: the HMR 55A local storm PMP obtained from the HMR PMP <br />Plates, <br /> <br />2. HMR.BV: the local storm PMP calculated by Black & Veatch (BV) by <br />applying an elevation adjustment to the HMR Plate PMP values, <br /> <br />3. HMRMVL: the local storm PMP based on on-site maximization and <br />transposition of the Masonville storm, the site-specific HMR 55/\ local storm, <br /> <br />4. HMRCYS: the local storm PMP based on the on-site maximization and <br />transposition of the Cheyenne storm, and <br /> <br />5. HMSPMP: the local storm PMP based on the on-site maximization and <br />transposition of the Extreme Thunderslmm atmosphere using the HMS CSM <br />Methodology <br /> <br />Table 10: Comparison of local storm PMP values based on technique used. <br /> <br />Method 1-hr 2-hr 3-hr <br />HMR- 11 .25 13.84" <br />Plate " <br />HMR-BV 5.74" 6.66" 7.06" <br />HMRMVL 6.02" 6.98" 7.40" ! <br />HMRCYS 2.72" 3.45" 3.77" <br /> .. . <br />HMS 3.92" 5.55" 5.95" I <br />PMP <br />% Diff -35% -20% -20% <br /> <br />4..hr <br /> <br />7.35" <br />r:ro" <br />4.01" <br /> <br />5.25" <br /> <br />.190/., <br /> <br />4", <br /> <br />5~hr 6-hr <br /> 15.20" <br />i'.58" 7.7(j" <br />'1'.94" 8.1 ~~" <br />4.65" 4.9:3 <br />E..50" 6.5(1" <br />-18% -20% <br /> <br />otal <br />5.20" <br />--. <br />7.75" <br />1.13" <br />j.41 " <br />".50" <br />-- <br />20% <br /> <br />If' <br />1 <br /> <br />f <br /> <br />6 <br />