WMOD00285 ‎(2)‎

• Title: Feasibility Study of Wintertime Cloud Seeding to Augment Arizona Water Supplies
• Date: 1/1/1987
• State: AZ
• Weather Modification - Doc Type: Report

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This cloud type often occurs prior to and following a low pressure
trough passage. Cloud presence may occur in a quasi-stationary state
from a few hours to a couple of days thus cldding substantially to its
appeal as a cloud treatment candidate.

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Figure 2. - Embedded convective cloud. Typical liquid water contents
are shown in g/m3. (Marwitz et .!l., 1976).,

The characterization of the embedded convective cloud (figure 2) is more
difficult due to its transient nature (lifetime of only several tens of
minutes) and associated measurement difficulties. Important features
include weak to moderate convection and c'loud-top temperatures colder by
only a couple of degrees than the encompassing stratus cloud. Its abi-
lity to generate large amounts of liquid water in the convective process
makes this cloud a potential candidate for treatment. Although ice par-
ticle concentrations may be high in these clouds, the convection is
often adequate to generate excess condensation (Cooper, 1985). This
cloud is frequently present in the unstable storm stage that often
follows the passage of a cold front. In the San Juan Mountains of
Colorado, it seems to offer substantial modification potential. This
cloud type may occur frequently over the Arizona mountains and offer
modification possibilities.

Though 1 ess understood, another wi ntertime cloud type that occu rs in the
California mountains, the San Juan Mountains of Colorado, and likely in
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