CWCB Wintertime Weather Mod Report

• Project Type: General OWC
• Applicant: Weather Modificaton
• Project Name: Colorado Weather Modification Program
• Title: CWCB Wintertime Weather Modification Report Fall 2002 - Spring 2003
• Date: 7/1/2003
• Water Conservation - Doc Type: Final Report

TABLE OF CONTENTS

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Section

1.0 INTRODUCTION ,..............................................,'............................................... 1

2.0 FEASIDILITYIDESIGN STUDy........................................................................ 2

2.1 Climatological Precipitation Infonnation ................................................ 2

2.2 Stonn Types ..,..........,............................................................,...............,... 3
2.3 Frequency of Significant Stonn Events .................................................... 4
2.4 Analysis of the Significant Stonn Events ................................................. 5
2.5 Atmospheric Stability............................................................................. 18
2.6 Cloud Seeding Project Design ................................................................ 20
2.6.1 Proposed Target Area ................................................................. 21
2.6.2 Operational Period ...................................................................... 21
2.6.3 Seedable Periods ........"................................................................ 23
2.6.4 Silver Iodide Seeding Generators ............................................... 23
2.6.5 Operational Decision Making .......................:............................. 26
2.6.6 Proposed Seeding Suspension Criteria ....................................... 26

2.7 Summary ..........................................................................................,...... 29

3.0 PERMITTING PROCESS AND PROmCT SET-UP ...................,.........;.......... 30

4.0 OPERATIONS ....................................,............................................................... 33

4.1 Operational Procedures ...................,...,................................................... 33
4.2 Operational Summary....................,........................................................ 40

5.0 EV ALUTATIONS OF SEEDING EFFECTIVENESS ...................................... 44

5.1 Precipitation Analysis ....,........................................................................ 46
5.1.1 Control Area Precipitation Gauge Sites ..................,................... 47
5.1.2 Target Area Gauge Sites ............................................................. 52
5.1.3 Regression Equation Development, February - March Period.. 55
5.1.4 Precipitation Evaluation Results ................................................. 56
5.2 Snowpack (Water Equivalent) Analysis ................................................. 57
5.2.1 Regression Equation Development ,............................................ 59
5.2.2 Evaluation Results (Snowpack) .................................................. 62
5.3 Potential Seeding Impacts during the First Half of April....................... 62
5.4 Summary of Precipitation and Estimated Seeding Effects and

Discussion ........................ ......... .....................,............................. ........... 63
5.5 Potential Seeding Impacts at the Rocky Mountain Biological

Laboratory ............. ......................................,................................ ,.... ."... 71
5.6 Potential Downwind Effects ......................,................,........................... 73