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15. Discussion on "physically possible" A W A Action: A W A will revise the report to reflect that the NWS SSS design storm is physically possible but is not and should not be associated with orographic enhancement, i.e. k-factors greater than ~.O. 20. Evaluate tempora~ and spatial adjustment factors for all storms A W A Action: A W A will' perform these computations 23. Backup data for the Depth Duration envelopment curve A W A Action: A W A will provide back-up one all updated storm isohyetal pattt:rns / data are incorporated. 24. Inflection point on the envelop curve. Basically, the envelopment curve is defined by the 1921 storm and the: 1935 storm. The problem is that the envelopment curve is trying to produce a Depth-;-Area relationship that reflects a physical storm using data from two separate storm types. 'The 1921 storm covered a relatively large area while the 1935 storm provided large rainfall amounts within very small centers. The problem is that the envelop curve is not handling the transition region between the storms very well because this transition region is trying to be faithful to both storms. This issue is not new. In the EPRI Wisconsin/Michigan study, a very similar issue arose where there were a group of storms that dictated the latge area size extreme rainfall amounts while another group of storms dictated the small area size extreme rainfall. This created a very similar issue when a single envelopment curve was constructed as the storm type changes from the dominate storm type for small areas to the dominate storm type for large areas. This issue was address under the topic storm commonality. A similar approach can be taken here. For other HMRs, separate storm types are identified and separate PMFs are determined for each storm type with the larger storm type producing the larger PMF being the PMP storm type. An approach similar to this could be taken with a physically consistent envelopment curve produced for using the 1921 storm and another envelopment curve produced using the 1935 storm. Each of these envelop curves could be constructed such that they met the Corps criteria of incremental PMP increasing as area SIze Increases. A W A Action: Continue discussions with the Corps as to the preferred approach. 25. Additional model~ng results from Flow Technologies. A W A contacted Mr. Trieste and he did not have any additional modeling results available. 26. 27.