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C"':> C\J ~ ,-. -- Hourly data was gathered only for days that exhibited an s-shaped or sinusoidal pen trace. Snowmelt runoff in this geographical region is driven by air temperature and solar radiation. The typical pattern for these factors is sinusoidal. Hourly patterns of snowmelt runoff with pen traces of other shapes indicate that less predictable weather events are occurring. Smooth sinusoidal pen traces reflect days with typical hourly temperature and solar radiation trends. Days in which chart-paper changes disrupted the pen trace or where large pen adjustments were made, were also excluded. Table 3 presents the periods studied, their lengths, and the number of days used in May and June for each year. Approximately 60 percent of the total days in the study periods were used in this analysis. This confirms that the sinusoidal shape is the typical nature of the hourly flow pattern. A larger percentage of the days in May are excluded than in June. This reflects the process of snow-pack ripening as well as the transitional nature of the weather in May. Gurley operating records were obtained for the 1978, 1979 and 1980 operating seasons. No records were available for 1976. These were used to check apparent anomalous shifts in flows between the Beaver and Gurley stations. Lack of data at diversion structures limited their use. TABLE 3 PERIODS STUDIED AT WEST BEAVER CREEK NEAR NORWOOD ~ Days in May Days in June Year Studv Period Used Total Used Total 1976 5/13-5/31 11 19 1977 1978 5/11-6/16 12 21 14 16 1979 5/14-6/23 6 18 16 23 1980 5/19-6/22 Q 13 ~ 22 35 81 45 61 Data Manipulation Hourly streamflow values were averaged for each day to obtain a calcGlated mean daily flow. These values were compared with published mean daily flow values. Days with deviations of more than three cfs were checked for errors in transcription, errors in selecting rating table 3