WMOD00416

• Title: Wintertime Cloud Systems Over the Rockies: Three Case Studies
• Date: 12/1/1980
• Weather Modification - Doc Type: Report

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seeding materials, ii) to describe the dominant microphysical processes,

and iii) to seek the availability of atmospheric covariates (predictors)

needed for analyses of research and applied weather modification pro-

grams. Basic data were obtained from (a) simultaneous rawinsonde obser-

vations upwind and downwind of the main barrier (the downwind rawinsonde

was available during COSE II only), (b) observations with two aircraft

equipped with cloud physics and state parameter packages (only one air-

craft during CaSE I), (c) vertically pointing Ku, K (CaSE II only), and

X (COSE II only) band radars, (d) ice crystal replicators at valley and

mountain sites, (e) observations of atmospheric particulates and nuclei

with Bigg-Warner and Mee ice nuclei counters, high volume and carbon

cup (COSE I only) samplers, and snow samples to obtain snow for chemical

analysis, (f) observations of boundary layer turbulent structure with

an acoustical sounder, (g) surface meteorological observations.of wind,

temperature, humidity, and precipitation at a minimum of seven valley

and mountain sites.

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1.4 Data Used in Analysis
The necessary data for the analysis of the case studies included:

rawinsonde measurements used to determine the upwind and lifted cloud

components, radar observations taken vertically at the upwind base of

the ridge, and visual observations, taken from the surface and aircraft,

that described each overall cloud system. Rawinsonde data was gathered

with an RD-65 rawinsonde unit upwind of the main barrier at Craig (see

Figure 2). The sounding data set was comprised of 71 soundings taken

during COSE I and 62 soundings taken during COSE II. In general,

balloons were launched as often as every three hours during storm