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<br />1.0 Introduction <br /> <br />The town of Buffalo Creek, Colorado was struck by a deadly flash flood <br />about 900PM on the night of July 12, 1996. The flash flood killed two residents <br />and produced several hundred thousand dollars of dama~le to the town. The <br />cruel irony of the flash flood is that it followed a massive forest fire which burned <br />12,000 acres of nearby forest land during May 1996. The combined hardships <br />associated with both of these disasters and the continuinq threat of additional <br />flash flooding has produced serious concerns for the remaining residents of <br />Buffalo Creek. <br /> <br />The town of Buffalo Creek is located in southern foothills of Jefferson <br />County about 35 miles southwest of downtown Denver (see Figure 1), The <br />elevation of the town of Buffalo Creek is about 7,200 feet but it is flanked by <br />10,421 ft Green Mountain to the south, 11,588 ft Buffalo Peak to the west- <br />southwest and 11,970 ft Windy Peak to the west (See Figure 2). The average <br />elevation of the watershed is about 8,500 feet. The Buffalo Creek basin extends <br />roughly 15 miles to the southwest from the town of Buffalo Creek and varies from <br />2 to 5 miles wide, The basin covers about 55 square miles of drainage area. It <br />is easy to imagine that orographic influences on precipitation exist in the basin. <br /> <br />Henz (1974) identified fourteen areas along the Colorado front Range <br />which he referred to as orogenic thunderstorm "hot spots" or preferred <br />orographic locations for thunderstorm generation. He observed that over 2,5 <br />times as many thunderstorms formed over these "hot spots" as the neighboring <br />terrain at elevations above 5,000 feet during the radar survey periods of the <br />summers of 1970 and 1971, He identified the orographic characteristics of these <br />hot spots were very similar and supportive of an enhanced mountain-valley <br />breeze circulation which appeared to be related to the observed increase in <br />storm formation over these areas, He recently observed (lHenz, 1996) that most <br />of the significant flash floods w~lich have occurred since 1976 along the <br />Colorado Front Range at elevations above 6,000 feet have occurred in one of <br />these "hot spots". The Buffalo Creek watershed is located within the southern <br />half of his Conifer "hot spot". <br /> <br />Many have suggested that the burn areas of the basin produced a <br />significant increase to the runoff from the rains of July 1 ih which acerbated the <br />flash flood. Others have suggested that the burn area has been responsible for <br />thunderstorm intensification and formation over the Buffalo Creek basin, This <br />report will not address those concerns directly, Rather, it will present a coherent <br />presentation of the timing, aerial coverage and intensity of the rainfall which <br />produced the Buffalo Creek flash flood, Discussions on the use of radar data <br />and standard surface and upper air observations to produee precipitation <br />mapping will be presented. <br /> <br />1 <br />