WMOD00317 ‎(2)‎

• Title: A Comparison of the Potential of Cloud Seeding to Enhance Mountain Snowpack in Colorado During Dry, Normal and Wet Winters
• Date: 1/1/1983
• State: CO
• Weather Modification - Doc Type: Report

be used to determine characteristics of the air mass over the state,
relial'x:::e upon them presents two problems.

First, scientists disagree as to how well storms can be identified
from soundiIl3s. Although new techniques ernployiIl3 radiometry have shown
promise in identifyiIl3 storms and seediIl3 potential, data to conduct a
clirnatologyusing these techniques are not available.

Second, soundings are taken too rarely and at too few locations to
provide enough data to conduct a comprehensive climatology. Soundings are
taken routinely twice daily by the National Weather Service at only two
locations in Colorado (Denver and Grand Junction). Thus, only educated
guesses can be made about conditions in the upper atmosphere over the
thousarrls of square miles between stations. Storms can also slip by
umetected between soundings taken l2 hours apart. Additional soundings
are available from field experiments in Colorado, but their period of
record is too short. Statistical considerations dictate that observations
be made over periods of time lOIl3 enough to allow confidence in results.
Also,. collecting data over a long period ensures that dry, normal, am wet
years are included in the sample.

Data with the areal coverage, spatial resolution am leIl3th of re<::ord
necessary for a comprehensi ve assessment of storms am seeding
opportunities do not exist. '!he conclusions of this study, are tentative
and subject to revision as additional data become available. In our
opinion, the best data available are interpolations of soumiIl3s taken by
the National Weather Service at two sites in Colorado am at four sites in
borderin:j' states. '!hese interpolations, corrputed by Dr. Owen Rhea as part
of his dissertation in atlrospheric sciences at Colorado State University
(Rhea, 1978), consist of values at ten border points around the portion of
Colorado west of 10SW lOIl3itude for the winter ronths (November 1 through
April 30) from 1961-62 through 1973-74.

Interpolation points are shown in Figure l. Before interpolatin:j,
Rhea corre<::ted the relative humidity profiles for lag effects of the
various sensors used during the 13-year period. These data were made

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