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

The objectives of this des ign study were:

..

. To provide a comprehensive review of the physics of winter
precipitation in the Sierra Nevada and to determine the applicability of previous
experience and program results to these processes.

.

. To develop a physical basis of precipitation modification
for the Sierra Nevada including the establishment of hypotheses of effect,
both local and in extended areas.

. To provide a scientifically valid and operationally viable
experimental des ign, including the identification of most appropriate areas,
operating systems, and operational procedures.

· To provide the meteorological, hydrological, and operational
background data necessary to the development of a comprehensive evaluation
of the possible environmental impacts associate.d with a snow augmentation
pilot program.

1.1

Summary

~

This report presents the results of the study and recommend-
ations for the conduct of a pilot program. The report is presented in three
volumes with an executive summary. This, the first volume, presents a
review of the setting for the program, including the meteorology and hydrology
of the Central and Northern Sierra Nevada, a review of the state of knowledge
of the cloud physics, and associated models with possible applicability to the
region. Volume IT of the report presents the proposed physical and statistical
models against which the program is recommended to be conducted. The
volume also includes a discussion of appropriate areas and methodology for
program evaluation. Volume III presents the operational design of the
recomrnended program, including instrumentation as well as procedures.
The environmental considerations for the program are presented in the
executive summary.

(fl.

. The first part of this volume is intended to provide a complete
background for the design. It begins with a review of the synoptic and meso-
scale climatology of the Sierra Nevada, followed by a similar review of the
state of knowledge of the cloud physics of winter storms in this region. The
result of a statistical study of snowfall relationships within the river basins

2