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46 FLOOD, JULY 3I-AUGUST 1, 1976, BIG THOMPSON RIVER, COLORADO - f . )-; FIGURE 40.-Large thunderstorm several miles southwest of Lyons, Colo., at about 1830 MDT, July 31. 1976. Photographs taken at Mitchell Lake looking east-northeast. only the 3-day rainfall totals. A tabulation of daily rainfalls for July 31-August 2, 1976, at 10 National Weather Service stations is shown in table 1, and total rainfall amounts for the same period at the 119 miscellaneous sites are shown in table 2. The precipita- tion summaries in tables 1 and 2 and the isohyetal map (figAl) were prepared by the National Weather Ser- vice, Central Regional Headquarters, in cooperation with other Federal agencies, For most of the area, the analysis in figure 41 pro- vides an overestimation of the actual precipitation which produced the flash flooding. Also, the analysis offers little evidence as to rainfall intensities associated with the severe flooding during the night of July 31-August 1. Two continuous rainfall records obtained in the Bellvue area northwest of Fort Collins and the record obtained at Allenspark (fig. 42) provide a good TABLE I.-Daily precipitation, in inches, Boulder and Larimer Counties. Colorado [T, trace; ". leaders indicates no data available] Location Time of 1976 Station observation July August Latitude Longitude IMDT) 31 1 2 Allenspark .. .......... 40012' 105032' 1700 0.02 0.50 0.90 Boulder..............,....... . 40000' 105016' 1700 T .12 .69 Boulder 2 ...................... 40001' 105016' Continuous 0 0 Estes Park.................... 40023' 105031' 1600 T 3.59 .87 Fort Collins.................,. 40035' 105005' 1900 .23 .11 .50 Fort Collins 9NW . . . . . . . . . . , . . . 40040' 105'13' Continuous 3.1 2.2 1.8 Longmont 6NW ...,.....,..... 40015' 105009' Continuous 0 0 .7 Nederland 2NNE ........,..... 39059' 105030' 0800 0 .19 .73 Red Feather Lakes 2SE.,....", 40048' 105034' 1700 1.20 .33 .12 Waterdale.................," , 40025' 105012' 0800 0 .33 .46