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<br />Ci ,,'Jip. <br /> <br />Weare trying to look into the details of this question, A couple of issues are impacting our <br />efforts... ,1) we have changed GIS guys and 2) we have upgraded our GIS software. However, <br />we do have the archived images and are trying to quantify the answer to this question. <br /> <br />Having said that, what appears to have happened is that one of the trial placements for the Falcon <br />1965 isohyetal pattern (see A W A response to Question 8.) was included in the March 2003 <br />version of the report instead ofthe final placement ofthe isohyetal pattern that is included in the <br />Final Report August 2003. An indication ofthat is the fact that the August 2003 pattern on page <br />69 of the Final Report has the Basin Average Rainfall included in the figure where the March <br />2003 version does not. Since the table of average rainfall depths from the two reports agree (as <br />the COE noted), it appears that the Figure 4,13 was the one actually used in both versions of the <br />report and the figure in the March 2003 is not correct figure for the computed rainfall depth. <br /> <br />11. Page 71. Why was the NWS isohyetal analysis not used for the 1965 Holly storm? <br /> <br />A W A response to Questionll. <br /> <br />A W A used GIS to produce an isohyetal pattern for this storm using all available rainfall data for <br />this storm center. Comparing this GIS derived rainfall pattern with the NWS isohyetal analysis, <br />the areas of extreme rainfall were larger using the GIS isohyetal pattern. A W A elected to use the <br />GIS isohyetal pattern since it provided the most conservative (largest) rainfall amounts. <br /> <br />12. Page 74. What does "1.50(a)" mean for the In-place Maximization factor? <br /> <br />A W A response to Question 12. <br /> <br />The answer to this question is the same as the answer to Question 3, <br /> <br />A W A concurs with the NWS conclusion that there should be upper limits place on in-place <br />maximization factors. The basis for this conclusion is that the maximization procedure assumes <br />that a storm's efficiency in converting atmospheric moisture to rainfall remains unchanged <br />during the maximization process, i.e. atmospheric moisture can be added up to the maximum <br />value used in the maximization process without changing the storm efficiency. Adding moisture <br />to the atmosphere associated with a rainfall event can and does have an effect on storm <br />efficiency and at some point the assumption that additional moisture has not effect on storm <br />efficient is not valid. NWS has adopted upper limits to storm maximization. HMR 51 applied a <br />limitation of 1.50 to the maximization factor (HMR 51, Section 3.2.2, page 28). HMR 55A, <br />Section 8.4..1.1, page 131, provides some discussion on limitations to in-place maximization <br />adjustment. HMR 55A adopted the 1.50 limit for the nonorographic region east of the <br />Orographic Separation Line (OSL) (HMR 55A, Section 5.4, page 88), Both HMR 55A and the <br />newer HMR 57 apply a limitation of 1. 70 in orographic regions. This limit was adopted to allow <br />for inadequacies of the storm sample in orographic regions (HMR 55A, Section 8.4.1.1, page <br />131; HMR 57, Section 7.2, page 66). A W A used the limitation of 1.50 for Cherry Creek and <br />annotated when it was applied with "1.50(a)", indicated that the adopted value of 1.50 was used <br />instead ofthe higher calculated in-place maximization value for the storm. <br />