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55A, Figure 8.3 shows the transposition limits for the Gibson Dam storm which clearly do not include the Cherry Creek basin location. HMR 44 also considered this storm for transpositioning over the South Platte River basin. It was transposed to the western slopes of the South Platte basin, well to the west of the Cherry Creek basin. HMR 55A, p. 43 in the discussion related to the Big Elk Meadows storm, states that the rainfall centers were located along the first upslopes. This storm characteristic is similar to Gibson Dam and hence this storm should only be transpositionable over and west of the first upslopes. Comment 4: The NWS used both HMR 55A and HMR 52 in their 1995 study. A W A has verified that HMR 55A within/without storm curves agree well with the A W A Colorado storm within/without curves for HMR 55A non-orographic PMP for region C. However, the orographic PMP curve for the Cherry Creek location is closer to the HMR 52 curve. Plotting ratios derived from Table 6 of the 1995 NWS study, the HMR 55A non-orographic ratio for the 24-hour time period for the 386 sq mi area of the Cherry Creek basin is 66%, only slightly higher than the A W A Colorado storms curve. However, the ratio for the 1995 study results is 77% (386 sq mi value of21.1" and an estimated 10 sq mi value of27.25" from Figure 4). Although the ratios from HMR 55A seem to be consistent with Colorado storms, the use ofHMR 55A PMP values together with HMR 52 produces significantly different results. Comment 5: The A W A team stated that the PMP estimates in HMR 55A for the Cherry Creek basin location were not reproducible using the information provided in the NWS FOI response to the CWCB request together with information contained in HMR 55A. Comment 6: While the A W A team does not endorse the NWS approach of using HMR 55A PMP values with the HMR 52 procedure and then applying K-factors, the team did verify that the NWS made no arithmetic errors in their computations. Comment 7: The NWS states that upslope conditions occurred in the May 30-31,1935 Cherry Creek storm but does not identify the winds (direction and magnitude) nor the slopes within the basin where the upslope conditions occurred. The A W A team would be pleased to acknowledge the upslope conditions when the supporting data are provided. The A W A team realizes that the NWS has not demonstrated that the use K - factors represents physical storm processes, either by evaluating historic storms nor in potential PMP storm scenarios. The National Research Council also recognizes that "physical justification for these procedures has not been established clearly." (NRC, 1994, P 13). The A W A team believes that the definition ofPMP (". ..physically possible. ..") requires demonstrating that K-factor represent physical storm processes. Ifin fact the K-factors represent convergence or divergence, or upslope or downslope resulting from topography, physical features can and should be identified. The NWS states the K -factors can be used because they are based on ... "what has been observed. The data themselves determine whether or not there is an orographic effect but do not provide a reason for the effect or rely on analysis ofthe storm scenario." The A W A team will accept this caveat if 1) some physical basis can be identified to support the K-factor