Show Weather modification ion program r sponsored throughout state For the filth fifth consecutive year the Utah Water Resources Development Corporation is sponsoring a weather modification program with the intent of increasing in the mountains The program conducted by North American Weather Consultants encompasses encompasses encompasses en en- compasses the following southern central and west central counties Tooele Juab Millard Beaver Deaver Washington Garfield Piute Plute Wayne Sevier Emery Sanpete Carbon Grand and San Juan In addition to these 14 counties North American Weather Consultants is also operating a snow pack increase program for Uintah Duchesne and Daggett counties These 17 counties are being assisted financially through cost- cost sharing funds from the Utah Water Resources Division The 78 1977 program which runs from November through April consists of ot seeding clouds with an expected return of 10 to 20 percent increase in The primary means of seeding are with wilh loo ground ground- based cloud nuclei generators Which are located throughout the target area with local residents who turn on the generators when contacted by the project personnel in Salt Lake City These ground seeders release silver silver- iodide particles that are carried up into the clouds with the air rising up and andover andover andover over the mountain barriers The particles par pare tides stimulate the storm to snow more than It would naturally without seeding means of releasing the silver particles is from airborne airborne air air- borne seeders which are attached to the three aircraft devoted to the program one stationed at St. St George and two at Salt Lake City Eight meteorologists are devoted to the cloud seeding project five in Salt Lake City two of whom direct the statewide operations and three aircraft aircraft air air- craft observers i one each at Milford and Roosevelt where weather radar and balloon tracking stations are located and one In St St. George who conducts airborne operations with the plane stationed there Support personnel personnel personnel per per- technicians and pilots are arc stationed at Salt Lake City Milford Roosevelt Centerfield and St. St George which brings brin the total to 22 individuals who are dedicated to the program The success of the Utah Cloud Seeding Program m. m which happens to be bethe bethe bethe the largest operational weather modification project in the world area area- wise is limited by a couple of factors The main one being that snowfall cannot be increased if there are no storms or clouds The basic concept of cloud seeding Isto is isto isto to improve upon the efficiency of naturally occurring storm systems One other limitation is that not all storms can be seeded with a net result of increased snowfall RESEARCH programs conducted throughout the Western United States have shown that certain types of storms present the greatest opportunity for increases while others produce no increased pre precipitation whatsoever Therefore it is necessary for project personnel to continually monitor all aspects of the storm in order to determine whether or not it should be seeded Some of the storm parameters the meteorologists look for are temperature temperature temperature tem tem- at the top of the clouds cloud depth direction and speed of the winds at the surface and higher in the atmosphere atmosphere atmosphere at at- and moisture available These and other variables are monitored through the National Weather Service data received at North American Weather Consultants Salt Lake City office and North American Weather Consultants own data network and equipment such as the two weather radar and balloon tracking stations Even though the program has these limitations the participating counties should expect on the order of 10 to 20 percent increases of and associated increases in spring run-off run above what would have occurred naturally These sort of statistics have been verified on similar programs conducted in the western United States and are arrived at through comparing actual precipitation records over several years of or operations of the Individual individual individual in In- programs BECAUSE of the natural variability of ot precipitation it would be impossible to look at a single storm and arrive at a percentage of percentage increase Increase num number ber Presently the Utah Water Resources Division is monitoring the cloud seeding programs and after a few years of data should be able to estimate just what the effects have been and what might be expected in the future Operations up to and including the Christmas weekend have been primarily in the northern portions of the state However there was one storm in mid mid December December where moderate to heavy storms were reported throughout the state and atmospheric atmospheric atmospheric at at- conditions cooperated such that seeding was conducted in all areas for over 36 hours |