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<br />002~94 <br /> <br />d. Southerly storms are characterized by imbedded convective <br />cells. These cells, as observed on the project radar, should <br />be seeded at high rates by airborne generators or flares. <br />In addition, the general orographic cloud background should <br />be seeded by the surface generators. <br /> <br />"2. Wi nd Speed <br /> <br />The predicted wind speed dictates whether nearby or more distant <br />generators are to be used. The generator design has been based <br />on a differentiation at 14 m/s. The forecast therefore should <br />indicate whether a 700-mb wind speed of less than or greater <br />than 14 m/s is expected. This forecast should be available at <br />least one-half hour before seeding generators are engaged." <br /> <br />Many of the above recommendations by MBA were based on various <br />assumptions about transport and diffusion of the nucleating agent <br />from the seeding generators. These assumptions are discussed in <br />detail in that report. In addition, the system of operational <br />procedures discussed below was recommended by MBA scientists. <br /> <br />Operational Procedures <br /> <br />An operational day would be declared for two circumstances: when <br />all other criteria are met and snow is forecast to fall within the <br />primary study area during the operational seeding period (1000 to <br />0800 hours), or snow is observed to fall within that area during a <br />period. Because there is approximately a 1- to 2-hour lag between <br />nuclei generation and seeding effect, MBA proposed a 2-hour lag <br />between seeding and data days. That is, a seeding day may be <br />declared and seeding operations started anytime after 0800 hours, <br />while data for a seeding day would be obtained during the previously <br />described statistical unit, 1000 to 0800 hours. Thus, MBA is fairly <br />certain that seeding and seeding effect would be included within the <br />same statistical grouping. No seeding would be started for the pres- <br />ent day after 0400 hours. Any seeding started after that time would <br />be included in the next day's data. However, seeding operations <br />begun prior to 0400 hours would be continued until 0800 hours. <br />Figure 2 shows the time sequence of the various events. <br /> <br />To minimize the effects of missed forecasts, observed precipitation, <br />which either has not been forecast or has been forecast incorrectly, <br />would be sufficient to declare an operational day. Seeding would <br />commence after an hour of observed precipitation, or a forecast which <br />indicates that the precipitation will continue for an additional hour. <br /> <br />I <br /> <br />19 <br />