CWCB Wintertime Weather Mod Report

• Project Type: General OWC
• Applicant: Weather Modificaton
• Project Name: Colorado Weather Modification Program
• Title: CWCB Wintertime Weather Modification Report Fall 2002 - Spring 2003
• Date: 7/1/2003
• Water Conservation - Doc Type: Final Report

I
I

\

I

I

I
I
I
I
I

)

'~..I~ --
-----

I

l

I

I

I

I

I
I

I

I

I

,
I
I

)

I

. Sufficient meteorological observation systems are currently available for credible
operational decision making.

. Given the number of precipitation and snowpack measurements within and near
the target area, the prospects for a viable evaluation of the effectiveness of the
seeding project are good.

2.6.1 Proposed Target Area

The proposed target area is defined as those areas within Gunnison County that lie
above 9,000' MSL, with the exception of some smaller areas in the extreme southwest
and northwest portions of the county. The location of the proposed target area is
provided in Figure 2.11. These regions of the county receive significant natural
precipitation during the winter time which normally accumulates as snowpack (refer to
Tables 2-1 and 2-2). This snowpack provides a vastmajority of the water for spring,.
summer and fall runoff in the various rivers and streams originating in these areas.

2.6.2 Operational Period

The potential operational period is defined as the months of November through
April. This period represents the primary winter snowpack accumulation period. October
is not included since the normal precipitation in the target area is less than the other
months (refer to Table 2-1) and the average 700mb temperatures (refer to Figure 2.9) are
not as favorable for the use of silver iodide which begins to become active at -5 DC. April
is included due to the amount of natural precipitation that occurs during the month and
the fact that snowpack actually increases at some of the higher elevations of the proposed
target area (refer to Table' 2-2). The main barriers mean elevation along the eastern
border of Gunnison County is approximately 12,000' MSL. Although there are no
measurements of snowpack at 12,000', it is anticipated that snowpack increases in the
11,000' to 12,000' elevation range based upon extrapolation of the information for

21