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Show TABLE 15 Silver-in-Precipitation from Rabbit Ears Snow Sample for Operation of 2 January 1969 Sampling Period Silver (parts per billion) 1830-1930 MST 0. 0 1930-2000 MST 0. 0 2000-2030 MST 0.0 2030-2130 MST 0. 0 2130-2230 MST 0. 0 2230-2300 MST 0. 1 2300-0030 MST 0. 0 the calculated period of seeding effect. Both of these phenomena are just the reve rse of what is frequ e ntly observed during se e ded periods. 4. 5. 3. 2. 7 Summary and Conclusions Th e data studied indicat es no e v id e nc e of seeding e ff ec t either in precipitation rat es, silver-in-precipitation, crys tal typ es or riming rates. Thus, the seeding material ve ry likely r e main ed trapped und e r the surface-based inve rsion. 4. 5.4 Airborne Seeding 4. 5. 4. 1 Case Study of Operations on 16 November 1968 The twelve hour period from 0700 MST to 19 00 MST on 16 November 19 68 encompasses both an airborne and a ground seeding eve nt , and was sel ecte d for detailed study . Droppable pyrotechnics were used for the airborne releas e . 4. 5. 4. 1. 1 Synopti c Map Pattern The l arge-sca l e flow patt e rn on this day f e atured moderately strong west northyve st flo w at th e 500 mb l evel w ith cyclonic curvature. A minor trou g h c ould be visualiz e d at 0500 MST from the 500 mb lo w ce nter to just northwest 211 |