WMOD00174 - Laserfiche WebLink

Home Browse Search

MAY 2lst. OPERATIONAL fJAY ii8: A weak cold front p'assed into the region ear.ly this afternoon allowing convergence and'strong surface heating to trigger storms along its boundary. This boundary could be seen on satellite running from Iowa southwest acrOBS Nebraska an~Kansas then further southwest into New Mexico. As storms began forming along the boundary, a ~pulsing~ effect was observed, which was fortunate for us. During such ~pulseB" incipient thunderstorms will build and collapse several times before enough moisture can ba lifted to saturate the middle levels and lower upper levels ot the atmosphere. Once the column of air in the cloud updraft has bean eufficiently moistened, a few of the building and collapsing clouds will develop into vigorous, severe thunderstorms. During such a time, when recognized, there is a brief ~window" in which to launch our aircraft prior to hail development in those clouds which appear to be best suited to become the primary severe storms. All planes were scrambled between 5:34 and 5:311 p.l\'!. Cloud base planes initially were sent as follows: one to a cluster ot storms southeast of Tribune, a second to a cloud between Lakin and Garden City; the other two to a group of clouds in southern Grant and southern Haskell counties. Storms generally moved slowly north- east. At 6:12 p.m. seeding for hail was initiated on the Greeley County storm where small hail was reported upon aircraft arrival (radar saw much larger hail forming in the cloud at the time); two aircraft also began seeding at 6:l2 in southern Grant County. Soon, a more solid line of storms had formed from south of Garden City southwest into Grant and Haskell counties. The plane, sent to cloud betWeen Lakin and Garden City earlier, was moved southwest down the line to encounter another storm in northwest HasKell Coun~y where seeding began at 6:27 p.m. Seeding continued until 7:3'2 p.m. then it move~ further south into Haskell County. When airborne at 6:l8 p.m., the cloud top plane was sent to the eastern Greeley storm which, by then, had moved into western Wichita County having just one cloud base plane working it. That storm was producing hail abou~ golf ball-size at the time. The cloud top aircraft was able to seed new cloud turrets on that Wichita County storm, which was near Leoti, between 6:49 p.m. and 7:12 p.m. before beingsant toa new storm on th~ Pinney/Lane county line, south of Dightoh. Surprisingly, cloud base seeding was ended on the Wichi~~ storm due to a lack of updrafts at 6:45 p.m. and the plane was sent toward the Grant/Haskell areas at 6:53; however, it was divertecl to the Lane/Finney storm at 7:12 p.ll1. Cloud top seading began at 7:19 p.m. on the Lane/Finney storm; the cloud base plane began at 7! 25 p.m.; radar indicated hail over southern Lane. Seed~ng in Lane continued at cloud base until 7:39 p.m. then moved to yet another detached storm about 15 NNE of Garden City Airport and began seeding at 7:47 p.m. Meanwhile, the cloud top plane seeded in southern Lane until 7:56 p.m. by which time the storm was weaker and moving near the target area boundary. Coincidentally, the dry ice dispenser had to be reloaded---which takes several minutes to do so. Subsequently, cloud top seeding was shifted to the storm NNE of Garden City Airport at B:08 p.m.