WMOD00204

• Contract/Permit #: #92-3
• Applicant: North American Weather
• Project Name: Willow Creek Basin
• Date: 11/1/1992
• Weather Modification - Doc Type: Application

ATIACHML'IT 1

Question 1:

The objective of the proposed project is to beneficially increase the natural
precipitation efficiency of winter storms affecting the designated target
area.

Question 2:

Target border runs along the Jackson/Grand County line from Parkview
Mountain in T4N, R78W to Cascade Mountain in the NE comer ofT4N,
R77W, tllen south along the ridgeline near the R77W and R76W border,
to Porphyry Peaks. Then south along the ridgeline to Apiatan Mountain
in the NW comer of TIN, R76W. From this point it runs along the ridge
line down to Willow Creek Reservoir and up to the ridge just south of
Willow Creek Reservoir in TIN, R76W. From here it travels WNW,
following the ridgeline to Elk Mountain in the NW comer of TIN, R78W.
From here it runs north through the Corral Peaks in TIN, R78W and on
north to Parkview Mountain. Figure 1 provides a map of this area.

Question 3:

The project will be operated from NAWC's main office in Salt Lake City,
Utah. The licensed meteorologists will bave access to all relevant
National Weather Service data distributed from Suitland, Maryland via
geostationary satellite to NA WC' s office through a Zephyr Weather
Service. Data includes surface hourly weather observations, upper-air
observations, analyzed weather charts, forecast weather charts, and visible
and infrared weather satellite imagery.

The program will utilize a network: of 15-20 ground based silver iodide
generators. These generators will be located at private residences. The
local residents will be trained in the operation of these generators. During
suitable storm periods the licensed NA WC meteorologists will call these
local operators and ask them to operate the-generator (either to turn on or
turn off the generator). Each generator will be attached to a propane
tank. A 2 % solution of silver iodide in acetone will be burned in a
propane flare resulting in the emission of trillions of tiny silver iodide
particles. The effectiveness of the NA WC generator that will be used is
provided in Figure 2 as tested in the Colorado State University cloud
simulation laboratory. Each generator will emit approximately eight (8)
grams of silver iodide per hour of operation.

The NAWC meteorologists will determine which generators, if any,
should be operated in any particular storm period based upon
consideration of wind flows and likely transport over the intended target
area. Normally not all generators will be operated at any given time.