WMOD00425

• Title: Demonstration of Improved Operational Water Resources Management Through Use of Better Snow Water Equivalent Information
• Date: 9/1/2002
• Weather Modification - Doc Type: Report

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CONTENTS

Page

Executive Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 111

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Background, Purpose, and Goals - Water Resources Management Applications ... 1
1.2 The WSR-88D Radar, Precipitation Processing Subsystem System, and SAA . . . . . 2
1.3 GCIP Applications of the SAA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Snowpack Estimation and Hydrologic Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.5 Annual Progress ..................................................... 4

2. Task Summaries ......................................................... 4

3. Topics in Previous Reports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Annual Report 1998 (Super, 1998) . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Annual Report 1999 (Matthews et aI., 2000) ....................,.......... 8
3.3 SAA Supplemental Report (Holroyd, 1999) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. SAA Development ....................................................... 9
4.1 Background and Approach ................... . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 Early Modifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
4.3 Real-Time Data Ingest ................................................ 12
5. SAA Implementation, Testing, and Results .................................... 13
6. SAA Refinement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
6.1 Adjustments to the Hybrid Scan and Occultation Files ....................... 15
6.2 Vertical Profile of Reflectivity Correction ................................. 15
6.3 Precipitation Type Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
6.3.1 Bright Band Characteristics ........................................ 20
6.3.2 Snow, Melting Snow, Rain Classification ............................. 22
6.4 Virga Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 25
6.5 Time-Height Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26

6.6 Case Studies ........................................................ 27

6.6.1 14 October 2000 - Predominately Rain ............................... 28
6.6.2 2 November 2000 - Predoininately Rain Showers. . . . . . . . . . . . . . . . . . . . . .. 32
6.6.3 6-7 November 2000 - Strong Stable Bright Band. . . . . . . . . . . . . . . . . . . . . .. 35
6.6.4 6 January 2001 - Virga Predominant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40
6.6.5 30 January 2001 - Bright Band Parameter Determination. . . . . . . . . . . . . . . " 43
6.6.6 7-8 February 2001 - Shallow Wind-driven Snowfall. . . . . . . . . . . . . . . . . . . .. 46
6.7 Statistical Analyses of the Cases ........................................ 49
6.8 Other Refinements ................................................... 51
7. P AA Output into SNODAS ................................................ 52
7.1 SNODAS Background ................................................ 52
7.2 PAA Data Formatting for SNODAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 53

8. Related Efforts .......................................................... 55

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