WMOD00298 ‎(2)‎

• Project Name: Project Skywater
• Title: Project Skywater - Fiscal Year 1979 Report
• Prepared By: US Department of Interior Bureau of Reclaimation
• Date: 3/1/1981
• Weather Modification - Doc Type: Report

The goal of this contr ct is to conduct and support weather modification
research in Kansas as art of the HIPLEX program. In 1979, attention shifted
from field work to ana ysis of collected data.

Results from 1979 stud"es show the following:

. About 66 percent f the days with clouds of interest to HIPLEX also are
days with severe we ther warnings. This condition may severely limit
the number of exper"mental events in Kansas because HIPLEX policy
prohibits operation during severe weather warnings.

. Analysis of mesos ale and small-scale synoptic features has identified
several parameters hich strongly influence convection for use in
forecasting procedu es. These are the equivalent potential temperature
field and its gradi nts, convergence fields, streamline analyses, and
isentropic cross se tions. Analysis of these parameters, when consid-
ered with other clo d-triggering mechanisms, can be used to accurately
predict the onset 0 convection that will result in precipitation.

. Case studies have been performed on selected days. Analyses have
developed relations ips between mesoscale features and have identified
factors significant y influencing convection, such as wet-bulb poten-
tial temperature fi ld and its associated vertical velocity field.

. The contractor ha developed algorithms for the automatic detection and
tracing of rain ~el s for processing digital weather radar data. The
radar cells are def ned by contours 3 dB below enclosed reflectivity
peaks which do not nclose other cells. Cell attributes such as
reflectivity area a d location are computed and compiled. These
analyses were perfo med on several cases and statistics of cell attri-
butes are under stu y at present. Cell attributes studied include cell
reflectivity area, ocation of cells, mergers, splits, cell duration,
motion, and tracks. Streamlines are also derived from cell motion in
the cell tracking p ogram.

All analysis efforts a e continuing and will be presented in the fiscal year
1980 report.

CONTRACTOR: National enter for Atmospheric Research/National Science
Foundat on, Boulder, Colorado
CONTRACT NO. 6-07-DR-2 040
PRINCIPAL INVESTIGATOR: Gerhart Langer
PERIOD: October 30, 1 75 - Continuing
FY79 FUNDING: $24,300
PURPOSE: Development f ice nucleus filters for HIPLEX

The primary emphasis 0 the NCAR studies of HIPLEX was placed on development
of membrane filters to increase the knowledge of ice-forming nucleus popula-
tions over selected si es. A major problem was to determine whether the
present membrane devel ping system could be modified to enable detection of
ice-nucleating particl s. Efforts were made to improve the present type of

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