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\ ,) , " , . . Presentation bv Mr. Ross Williams: Mr. Williams gave a brief presentation showing the uses of Geographical Information System in the Cherry Creek PMP project. These included uses included general location maps, storm isohyetal maps for the June 16,17, 1965, and May 30-31, 1935 storms, moisture inflow / hill shading maps, ridgeline and barrier profiles, and uses for paleoflood investigations, Mr. Williams and Dr. Tomlinson explained that the moisture inflow / hill shade maps were created to give the reader an visual understanding of what a rain shadow "looks" like in relation to upwind moisture barriers, . Presentation bv Mr. John Heuz: Mr, Henz presented a thorough report on the relationships ofthe major Cherry Creek Basin storms to the surrounding terrain, The following are brief discussions of his presentation: o Map: an overlay of all three storms and their orientation to each other; Cherry Creek Basin was not overly effected by these historical storms; Mr. Henz suggested that there could be a hidden pattern to the development of these storms, o HMR 52 suggests a 2,5-1 ratio for historical storms; the storms that occurred in the vicinity of the Cherry Creek Basin have possessed ratios of3.5, to 4,5, 1; HMR 52 allows multi-cell iflhe storm volume remains the same, o Map: the storm axis along the peak rainfall centers for each storm; the Plum Creek orientation is 187 degrees, while the Falcon storm is 227 and the Cherry Creek storm is 230 degrees; most of the storm axis originate on the slopes of Pikes Peak, o The storm axis for the 4,inch isohyetal pattern still originates on the slopes of Pikes Peak, o A sort of "cotmect the dots" method suggests that an arc exists over the axis of the storm centers for an event roughly orthogonal to the arcs; this phenomenon could be related to a mountain wave from Pikes Peak; the storm centers are roughly equal-distance to each other and show a repetitious pattern, o Map: Best fit curves for the mountain waves as they move away from Iheir origin on Pikes Peak; the distance between the peak rainfall centers is fairly equal-distance; this idea could be used to find a new set of rainfall centers that haven't yet occurred in the Cherry Creek Basin; because of the equal-distance between rainfall centers, a new axis could be developed in the area of the CC Basin with an orientation of 197 degrees, o Mr, Henz suggested that this new arc could be a "missing link storm" and asked why no major storms have occurred in the bounds of the CC Basin, o Map: the 4 inch isohyetal pattern placed over the CC Basin, o The new, model storm misses about half ofthe CC Basin; if one were to move the Plum Creek storm one basin over, most of the large rainfall centers would occur in the upper portion of the CC Basin which differs from the NWS model which places the storm center in the exact middle of the basin, 3