Laserfiche WebLink
<br />) <br /> <br />supplies when the snow melt occurs. Hydrologists routinely use water content to make <br /> <br /> <br />forecasts of streamflow during the spring and early summer months. <br /> <br />Tht1re are some problems with snowpack that must be recognized when using <br /> <br />snow water content to evaluate seeding effectiveness. One problem area that can occur <br /> <br />is that not all winter storms are cold and sometimes rain as well as snow falls in the <br /> <br /> <br />mountains. n.l'; can lead to a disparity between precipitation totals which measures <br /> <br /> <br />everything that falls and snowpack water content which measures only the water in the <br /> <br />snowpack, particularly at lower elevations. Also, warm periods can occur after a <br /> <br />snowfall (storm) and if the snow has fallen between the monthly snowcourse <br /> <br /> <br />measurements and then a warm period occurs, some of the precipitation that fell as snow <br /> <br /> <br />will have melted or sublimated by the time the next snowcourse measurement was made <br /> <br /> <br />and will never be recorded (even though some of the melted snow may have gone into <br /> <br /> <br />the ground to recharge the ground water). This is less of a problem with the advent of <br /> <br /> <br />the daily SNOTEL measurements. This can also lead to a greater disparity between <br /> <br /> <br />snow water content at higher elevations (where less snow will melt in warm weather) <br /> <br />than at lower elevations. <br /> <br />In the Willow Creek project, seeding did not begin until February, 1994 and so <br />any snow that fell before this month (a large percentage of the winter's total) was <br />consequently not seeded. This will lead to a dilution effect of the analysis results, since <br />the pre-February snowfall is included in the April I reading. <br /> <br />5.2.1 Selection of Tarl!:et and Control Areas <br /> <br />The target area contained two SNOTEL sites; these were the Willow Creek Pass <br /> <br /> <br />snowcourse and the Willow Creek Pass Pillow. They were co-located and were both <br /> <br /> <br />used as the target sites. Unfortunately, there are no other long-term precipitation <br /> <br />observations sites within the target area. <br /> <br />5-4 <br />