WMOD00058

• Contract/Permit #: #98-1
• Applicant: Western Kansas Groundwater Management
• Project Name: Western Kansas Weather Modification Program
• Date: 4/28/2001
• Weather Modification - Doc Type: Report

'~
I
I
I
I
I I
I
I
I
I
I
I
I
I
I
I
I
I
J

1997-2001
Operational Seeding Days
In Western Kansas

Former Percent of
Program North South Common Common
Year Ops Davs TarlJet Target Ops Days Ops Days
1997 74 47 66 37 32.4 %
1998 68 44 55 15 15.2 %
1999 68 33 62 26 27.4 %
2000 50 28 45 23 31.5 %
2001 61 61
5-Year Average: 64,2 57.8
Table 2

The steady trend of declining number of seeding days per year from 1996 finally reversed
itself This can be seen in the Column of Program Ops (Operational) Days in Table 2, Also,
Table. 2 shows the program operational seeding day breakdown for the previous two target areas
in the Tecent past. Last year the combined target areas produced 50 seeding days; whereas, in
2001 our current (single) target area had 61 days, Total seeding flight time in 2001 was 950
hours with 722.2 hours total seeding time; 119,176 grams of Agl were burned and 1,740
kilograms of dry ice were dropped by the cloud top aircraft.

This year the pure hail suppression (only) flights numbered 205, or 49% of all seeding
flights and observation flights; whereas, there were 23 rainfall seeding flights (only), 5% of all
seeding flights. The combined hail and rain seeding flights added up to 95, for 23% with the
remaining 96 flights being observation flights (also 23% of the total).

The distribution of types of seeding days were: 56 days upon which some seeding for hail
was performed and 40 days with some rainfall stimulation attempted, There were just 5 days
when the only seeding done was for rainfall stimulation and 19 seeding days in which only hail
suppression seeding was performed.

Interestingly, our silver iodide output this season amounted to nearly the same as last year
while we were enduring a drought and had the expanded target area...119,176 grams in 2001 vs
117,396 grams in 2000. However, dry ice release was lower at 1740 kg this year vs. 2,089 kg last
year. More silver iodide would have been burned and more dry ice would have been dropped
except for the grounding of the all aircraft by the FAA on Sept. 11 th for the cloud base planes and
for mandated maintenance on the Cheyenne that began at nearly the same time,

26