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1993-94, or excessively wet as in 1992-93. This extreme weather has significantly reduced the number of randomized cases obtained after three years (87 actual versus 180 expected). It is anticipated that the project would need to be continued at least two years beyond the five years intended to achieve statistical significance. All of the remaining winter seasons would need to have near normal precipitation. Adding two or more years would require extension of the environmental permits, which may require public revie\"". Thirdly, physical studies relating specifically to the transport of the tracer SF" (sulfur hexaflouride) within the target area have shown that moderate to strong downdrafts and updrafts to the lee of the main Sierra crest (mountain lee waves, which often occur prior to storm frontal passage but are much less dominant in post-frontal patterns) have a significant impact on the successful targeting of seeding-produced ice crystals. These results indicate that one solution to this problem would be to move the dispensers farther west and south of their current locations to extend crystal growth time before the crystals pass into this strong vertical motion field. This relocation would require an amendment to the EIR/EIS and a period of public review, and a possible year delay in the project. The LOREP field activities during 1991-92 and 1992-93 are documented by Reynolds (1992b and 1993) in annual project reports available from DWR. The annual report of 1992-93 field activities (Reynolds, 1993) includes findings from SF" tracer studies, verification of the G"CIDE (seeding guidance) numerical targeting model, and preliminary results from the statistical analysis of the randomized seeding cases obtained during the first two winter field seasons. This final report summarizes the field activities conducted during all three winter field seasons. However, more emphasis is given 10 activities from the 1993-94 field season, 'which were not reported previously in D\VR annual reports. The effects of mountain gravity waves or "lee waves" will be reviewed based on analysis of the project rawinsonde balloon ascent rate. The combination of the horizontal winds and vertical velocities computed from balloon tracking allows initialization of the Reclamation's GUIDE model. The model computations allow an assessment ofthe impact these waves have on the successful targeting of seeding effects within the precipitation gauge network. As has been emphasized repeatedly (Reynolds, 1988; Super 1990), it is imperative that transport and dispersion studies be conducted within any intended cloud seeding project area. These studies are needed to determine whether ground-based seeding can place a sufficient number of ice embryos into supercooled liquid cloud regions long enough to produce substantial crystal growth for fallout within the intended target area. Results will be provided from the use of a remote radar wind profileI' installed within the target area to determine how the wind field changes during seeding operations. Although the profileI' was unable to provide continuous vertical velocity data, its ability to accurately measure the horizontal winds hourly demonstrates its value as a tool in assessing the variable nature of the winds during winter storms. The frequency and magnitude of supercooled liquid water will be reviewed by analysis of the project's mountain-top icing data. Supercooled liquid water is necessary if cloud seeding is to succeed. The magnitude and temperature of the liquid water is critical to the rate of growth of seeded ice particles. This growth rate then impacts how quickly the crystals will fall out of the cloud as precipitation particles, or "snowflakes." 2