WMOD00011

• Applicant: Don Griffith North American Weather Consultants, Inc.
• Sponsor Name: City and County of Gunnison
• Project Name: Cloud Seeding Evaluation
• Title: The Development, Conduct and Evaluation of a Cloud Seeding Program for the Gunnison River Basin, Colorado During the 2003-2004 Season
• Prepared For: City and County of Gunnison
• Prepared By: North American Weather Consultants
• Date: 8/1/2004
• County: Gunnison
• Weather Modification - Doc Type: Report

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It is clear that the results from the snowpack evaluation differ substantially from those in
the precipitation evaluation. While the reasons for this are not fully understood. the results are
further discussed in Section 4.4.

..t3 Potential Seeding Impacts During the Firsll-lalf of April

The seeding program continued through the first half of April. This was an active stonn
period. with tv.:o seeded storms. The two storms produced approximately 3 inches of additional
precipitation during this period. We have not attempted any formal evaluation of the seeding in
the first half of April. If the results from the snowpack evaluation described in the previous
section were valid for these storms, a 13% increase for an average 3 inches of snow water
content would equate to approximately an additional 0.35 inches of snow water content. Figure
4.6 provides a plol of the precipitation and snow water content observed at the Porphyry Creek
SNOTEL site for Ihe first half of April.

Porphyry Cr~~k, CO Snot~l Site
Let 3. 29' It L.... n' 21' W E1u II?U h.t IIRCS ID ..U3i !loWS tD PRPt2
..

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Da'j of VeM

1./11
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(l< Ace. Pr~ipit"'tion + ~ ~t.er Content

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Fi~ure- 4.6 PorphYr)-" Cree-I\. S~OTEL graph for April 1-16. 2004

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