WMOD00011

• Applicant: Don Griffith North American Weather Consultants, Inc.
• Sponsor Name: City and County of Gunnison
• Project Name: Cloud Seeding Evaluation
• Title: The Development, Conduct and Evaluation of a Cloud Seeding Program for the Gunnison River Basin, Colorado During the 2003-2004 Season
• Prepared For: City and County of Gunnison
• Prepared By: North American Weather Consultants
• Date: 8/1/2004
• County: Gunnison
• Weather Modification - Doc Type: Report

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3.2 Operational Summary

This section summarizes the wcather conditions and seeding operations during storm
events. All times are loca] (.\1ST/MDT) unless otherwise noted. ~umbers in parentheses
correspond to the numbered stann events listed in Table 3-1.

;\ion'mber 2003

The month of November \\'as close to nonnal in the Gunnison Basin. ,....ith relatively
small but frequem stonn events affecting the area. Three storm events were seeded during the
latter half oflhe month. after the stan of the program on November lSlh.

The first seeded storm of the season occurred on ~ovember 17, as a staml system moved
from Utah into Colorado. Snow fell throughout much of the day. with a cold front reaching the
area in the early afternoon. Seeding '\;as conducted throughout the day, and S~OTEL data
indicated accumulations of 0.5 - 1.0" of snow water content in most of the basin.

The next stoml event affected the Gunnison Basin on November 22 (#2), as a cold front
and associated snow band crossed the area. Snow began falling around mid-morning and tapered
off later in the afternoon. Windy conditions were reported with this stonn event, and most snow
accumulations were fairly light. Seeding was conducted from mid-morning until early evening.
SNOTEL data indicated about O.5"'of water equivalent in most areas.

A moist northwesterly wind flow brought snow showers to the area on NO\"ember 26
(#3). The temperatures were favorable for seeding. about -10 C at the 700-rob level. with a well-
mixed atmosphere. Seeding was conducted from about 0900 to :WOO .MST. Snow
accumulations were fairly light in most areas. with generator operators reporting about 1-3" of
snow. and S:-':OTEL data indicating less than OS' of water equi\'alent.

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