WMOD00305

• Title: Weather Modification Design Study for Streamflow Augmentation in the Northern Sierra Nevada - Volume 1
• Prepared For: US Dept. of Interior
• Prepared By: MBAssociates
• Date: 7/1/1976
• State: CA
• Weather Modification - Doc Type: Report

TABLE OF CONTENTS

Section

Title

Page

.

1.0
1.1
1.2
2. 0

INTRODUCTION AND SUMMAR Y 1

Summary 2
Other Publications from this Study 4

MACROSCALE AND MESOSCALE CLIMATOLOGY
OF THE SIERRA NEVADA 5

Synoptic Conditions in the Sierra Nevada 5
Wind Characteristics and Storm Categorization 10
Horizontal Mesoscale Winds 11
Vertical Mesoscale Winds 14
Orographic Influence on Wind, Temperature
and Motion Fields 16
Temperature, Cloud-Top, and Precipitation
Climatoligies 18
Temperature 18
Cloud Tops 21
Conditions Near Precipitation Bands 21
Generality of Band Characteristics 23
Inversions 23

.

2. 1
2. 2
2. 3
2.4
2. 5

2. 6

2. 6. 1
2.6.2
2. 7
2. 7. 1
2. 7.2

3.0
l.l
3. 2

CLOUD PHYSICS CONSIDERATIONS 25

Background 25
Detailed Microphysics of Sierra and Related
Wintertime Clouds 30
Snow Crystal Habits and Dimensions 3]
Ice Crystal Concentrations and Cloud Top
Temperature 34
Liquid Water Formation 37
Riming 38
Applicability of Results 41
Review of Nucleating Agents 4l

PRECIPITATION ANALYSIS 49

General 49
Data Sources 49
Statistical Analyses of the Data Base 50
Snowfall Characteristics 52
Rates and Duration 52
Relationship to Orography 53
Statistical Cor relation 55
Intra-Basin Results (Daily) 55
Intel"-Basin Results (Daily) 61
Intra-Basin Results (Hourly) 61
Storm Duration by Type 62
Snowpack and Runoff Relationships 64

"

3. 2. 1
3. 2. 2

3.2. 3
3.2.4
3.3
3.4

4.0

4. 1
4.2
4.3
4.4
4. 4. 1
4.4.2
4.5
4. 5. 1
4. 5. 2
4. 5. 3
4.6
4.7

'.

i