WMOD00079 - Laserfiche WebLink

Home Browse Search

All eight cloud base planes were equipped with wing racks this year compared to just four planes having them in 1997. The racks, made from stainless steel and mounted to the trailing edges of the wings, each have positions for 12 pyrotechnic devices, commonly referred to as 'flares' which hold the flares in place while they bum to a stub. The flares used for hail suppression this year was the same 120-gram units we used in 1997 which were manufactured in Canada. Hail suppression flares make possible the addition of significant quantities of ice nuclei when they are needed in vigorous cloud updrafts which would otherwise be beyond our capability to seed properly using just wing generators. Our primary reason for using the flares has been to add a greater capacity to combat severe storms in the early part of the season leading up through wheat harvest. That period generally coincides with the greatest period of storm damage to all crops. By the conclusion of wheat harvest in early to mid-July the next primary crop of concern is corn, which is generally a little more resilient to hail damage. Wheat and com are the two main crops grown in the region, however, more wheat is grown than com. Milo, soybeans and sunflowers round out the main grain crops in the 'area: Crop-hail damage this year was distributed differently than most other years and the supply of flares was adequate through June. No shortages of flares were noted on any of the major hail-days (most significant damage clustered around periods in late-May and in the third week of June). After the flare supply effectively ended on July 10th, hail claim data indicated no widespread hail damage occurred. A second type of flare was used, but only for rain stimulation. It was a 500-gram hygroscopic unit distributed by Atmospherics, Inc., from Fresno, CA. The hygroscopic flares were not purchased for use at the outset of the program, but were acquired in late July in response to an extremely dry June which appeared to have the potential to continue further into the summer. The Dodge City-based Navajo was equipped with a dry ice dispenser capable of carrying nearly 200 pounds which dispenses dry ice at 5 pounds per minute. Almost another full load of dry ice was carried aboard in Styrofoam containers to extend its in-flight seeding capability. Typically, the plane ran low on fuel before it ran out of dry ice during operations. Seeding was done at altitudes in which a temperatures of -1 OC could be found. This altitude varies throughout the summer but often stays around 20,000 feet. Cloud top flight paths are either through the tops of newly developing clouds close to the parent storm, or through new storm growth on multi-celled lines (see Figure 2 on page 8). This season another dry ice reloading base was built in Scott City providing a more centrally located re-staging area within the overall WKWMP target area. As a result, the cloud top aircraft was able to stay aloft much longer on several occasions before having to descend for fuel and his turn- around times were faster than usual. The Navajo was sold shortly after the end of the 1998 program. The design of the WKWMP is similar to other seeding programs of its kind: The meteorologist makes the operational decision to launch and guide a seeding aircraft to a desired seeding position. Once a pilot arrives at the storm, he confers with his meteorologist and a seeding decision is made. Unless an aircraft runs into emergencies, runs out of seeding agent or is low on fuel, flight termination decisions are made by the meteorologist. WKWMP pilots are well-trained, most obtain a season of seeding experience as an intern prior to flying as pilot-in-command. Communications and teamwork must work well in order for the WKWMP to operate effectively and be successful. 18