WMOD00071

• Applicant: Western Weather Consultants
• Project Name: Vail Pass
• Date: 11/1/1984
• Weather Modification - Doc Type: Application

Fr"...... ";; D;...-...."'sr.c. PrtY_eJ...-e ;;-.)/;;."AJ....d-;r:.. uf #/,/,4re>"f 5~~J'''''J EJf.:.i-J f..--...,.."
Obler..e.! c../<-_d t-1f'e:i (},'~r tt:,,? (...1.::,./1.1.... ;::...~r ,)p.s;,' P..l~.t ~-"J"'d-" ~ J...Hjer",,{fN.[ 1'176

A cO:I:p.:lri$on of th~ not"::131ized seed/r.o-seed ["ot10.$ in the areas
rr.ost likely ;:0 be affected to the nv~~aJ;e effect ~crcss the p~ojecc. .md (0
the individ~l sice 'a~ios in Jobles J,t an~~1.~ i~dicatcS so~~ very

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interestinG probable seed effects. 'rf,)[" e...ery delle crp.!: in Tables J. 1 and
1.2. the seed/no-seed ratios i!:lpro-vccl--in so;:;e cases subs::onti....lly. Such
an oven.helming 1ndic:Ltion "'ould likely 5u~be!:t an o\"er~tl f.:lvor<:lb!.e: seerliilE-'".
response in the project arl:'a for 2.t It::lst half of th~ obs~rved cloud types
and a favornble tend~acy for tl.'O :."!or~ !:yp.::s, Another very intl..'rcsting

potnt to make Is th.:tt -.oller. tt...: :-,'.-,::..::': .":(:;l;'::;'-H.!(:..! r:uio.1s C.:iCl:l,:ltCt.! (.\'..,1:

the entire projcct. urea for =11. ..:1.ouJ ::j'pcs fer <In fi....e ycars of th~
pl:osr.Jm~ the rcsult is a s.ccd!Il')-~..:~d ~.:Il:.fo of O.lj7. :1h~n the s.ccJ/n<J-s.::e<i
fatio is calculated ct.:nt::!rcd d:: tl:c r.:(l~t-li:';'~l: .:11:;;:0 to be effcct.::d ;;6ain
for ~ll gf th.e same <:Iouu r~T'::;' ~l,..!. fl" the entire five ye:Hs of tll\.! Pilo::.
Project. the resul:in; ratto i~ 1.1~" .his could be interpreted as a
14 percent incre.::ts~ iro ?recii-i!:,,<:ien fro the eXr-ectcd o:rcas of- effect for .:ill
the seeded d.OlYs," precipH:Oltio:t in COl::p.:.:-iso" <:c All the ~on-!>cet!e~ d.:aj's.
preclp!t.1Cion. This sllZbestcd at/parcnt foe-reust! in preclpita,cion, as a
result of selective cloud seedinG csin~ the ~per~tional criteria of the
Pilot Project. is also very near the estinated 16 percent increase in the
ori~inal project design. These results might also support _as _essentially
correct the gross oper3tional criteri.:a utilized during the-five seosons
of the Pilot Project.
Another point to oake is th~t in both the Climax and th~ ~olf Creck
veacher modlfic3tion projects conducted by Color~do State University.
the project areas incl~ded both the up~ind arod the lee sides of the oountain
barrier. Durin& high vind occu:c~nccs ever these barriers. falli~v. pre-
cipit3tion could be tr.:lLlSportcc fro:::! tl~.!: I.,,"indl.'ord to the lee :oidc of the
barrier.. In these projc-cc.s these n.H.ur,Jl .:idjustr:c.nts- in the precipitation
fallout pottbrns ~ould be over~~~d out as net zero ~ffce-ts or a Qu~h smaller
precipit3tlon decre.:!sc thal1 ":flll!d be e;:lo.:uL3ted for the S.i1mt! typ~ of
occu'Crence for the seed in; result:> (It t:1~ Pilot Project. The reason for this
vas ch3t.onlv the \,.ind.....anl sille c~ th~ barrier 1.'.:a!> includ~d .us the t.:tt'get
or nffccted area for. scecir.~ rc:;ults ie the cesisn of the Pilet Project.
Also. both the ClilT:.3:t and the !-!olf Creek. projects alljusted their l;cnerator
netl..'Orks for v:!rious '-"il;d l!tccc:tic;,:s dl:ril'b :;eedins opt!r.:J.tions so ;JS to

a!l.;..1)'s ti!rhec th~ ~ccdin; r.:I~cd,;1l cO\....1:-.1s ~1 $j1ccific j1oit~t or nrc.:l oi

effect. Cor.scquI~ntl:'. ::he Jia;:r:ostic ~'..:!l:.:.1.tio:l :)['\~ccclu=<.! used heec in
P.1rt J ',:oIJIJ r.:llre ~;ir.:~L::tc. a .:;t:;:iL!r .:I=~:I of effect ,IF:lro;~ch t,j ~':;!lu.:\thlt~

.th.:. st!eclir.;: results C'f :..hc: :':t"t Pr"'j',:c,- ,j;!;::! ~;i:~;:... li0 .'no: rl)~nt il: the
Pil..t._ rr~ jcr::t t:u;t;.::-:: ;:~C";l ,:,nl'l.d _:21\-::'.1~-s ,::.:. ~,'CC(~cJ l'~t~,.;. ."!l,L t:ir:d dir.::ct.i<lns.

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