WMOD00527

• Title: Quantitative Precipitation Forecasting for Improving Reservoir Operations
• Date: 4/1/1995
• Weather Modification - Doc Type: Report

CONTENTS

Page

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

2. Combining orographic precipitation and runoff models for improving reservoir operations ... 1
2.1 Orographic precipitation model description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.2 Hydrologic model description ............................................. 2
2.3 Study area and topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4 Data used in study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4.1 Precipitation data ................................................ 5
2.4.2 Rawinsonde data ................................................. 6
2.4.3 Other data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12
2.5 Data analysis methods ................................................. 12
2.6 Statistical results ..................................................... 14
2.6.1 Precipitation ................................................... 14
2.6.2 Simulated inflow to Folsom Reservoir. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.7 Prognostic gridded field data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.7.1 Past method of using the orographic precipitation model .................. 18
2.7.2 Present method of using the orographic precipitation model . . . . . . . . . . . . . . .. 19
2.8 Status of QPFs and numerical models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
2.8.1 Rhea orographic precipitation model ................................. 19
2.8.2 Future NWS hydrologic forecasting support . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.8.3 Future mesoscale numerical models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

.3. Assessment of how meteorological applied research might improve Reclamation's
water operations ...................................................... 23
3.1 Questionnaire on meteorological support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.2 Potential for collaboration on meteorological applied research . . . . . . . . . . . . . . . . . . . . 25

4. Bibliography ............................................................ 28

Appendix Questionnaire about how meteorological support might improve
Reclamation's water operations ........................................ 29

TABLES

Table

1 Selected SCPP storm periods with heavy precipitation. . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Selected precipitation gauge sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Comparison of 12-h precipitation accumulations from collocated gauges in
the American River Basin ................................................. 8
4 Comparison of Oakland and Sheridan rawinsonde data .. . . . . . . . . . . . . . . . . . . . . . .. 11
5 Model and observed 12-h precipitation averages for a group of 22 precipitation
gauge sites in the American River Basin .................................... 14
6 Individual rankings of questions included in questionnaire on
meteorological support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7 Summary of mean rating responses to questionnaire ........................... 24

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