WMOD00498

• Title: Some Climatological Characteristics of Seedable Upslope Cloud Systems in the High Plains
• Date: 3/1/1973
• Weather Modification - Doc Type: Report

surface observations in the United States as defined in the Federal

Meteorological Handbook No. 1 (1969) and are presented in Appendix A.
The significant information conveyed by table 2 is the high frequency
of light and very light precipitation intensities. Although 55 percent
of the seedable layers produce precipitation naturally, 95 percent of
the natural precipitation is of light or very light lntensity. The
suitability of these precipitating cloud systems for ~rtificial
precipitation augmentation will depend on tAe new balance that can
be attained between artificial changes in the intensity. of precipita-
.

,

tion and,corresponding changes in its duration and areal coverage.
Table 3 shows the relative frequency of morning and evening

UPSLOPE' 'SEEDABLE' SITUATIONS
o

Figure 15: Percentage of upsZope
cloud systems from which pre-
cipitation was faZling when
the rawinsonde,was released.

Percentage of

Precipltattng Layers

21