Hurricanes and Forest Fires -62- 



'active squall line, appearing as an almost continuous line of 

 cumulonimbus with cirrus tops to an estimated 60,000 feet, 

 was observed as a spiral extending out from the center-base 

 at 20,000 feet near the outer wall, lifting to 35,000 feet at the 

 edge. 



"Approach to the storm center was effected from the south- 

 west, this course bringing the group into the storm's right rear 

 quandrant. After a brief reconnaissance flight around the outer 

 wall, the decision was made to seed a track over the uppermost 

 cloud shelf and at a distance from the center sufficient to permit 

 the control aircraft to fly contact 5000 feet above the seeding air- 

 craft. 



"A formation intrail was used, with the seeding aircraft (B-17 

 No. 5560) leading at cloud top level. The photoreconnaissance air- 

 craft (B-17 No. 7746) followed the seed ship, 3000 feet above and 

 1/2 mile astern, with the control aircraft (B-29 No. 816) trailing 

 5000 feet above and 15-20 miles astern. 



"Seeding commenced at 29.8 degrees North, 74.9 degrees 

 West at 11:38 EST at an altitude of 19,200 feet, the outside air 

 temperature being approximately -5°C. Continuous seeding was 

 effected along a straight course to 30.2 degrees N, 73.9 degrees 

 W, thence to 30.8 degrees N, 73.1 degrees W, at which point (12:08 

 EST) seeding was stopped. During this 30-minute period 80 pounds 

 of solid carbon dioxide was dispensed along the 110-mile track. 

 In addition, two mass drops of 50 pounds each were made into a 

 large cumulus top at 30.7 degrees N, 73.4 degrees W. 



"Upon completion of this phase, all planes flew a reverse 

 course back along the seeded track, taking visual and photographic 

 observations. No attempt was made to penetrate through the wall 

 of the storm into the eye or to seed in or near the above-mentioned 

 squall line, owing to the failure of the group's homing aids (radio, 

 compass, and visual flares). It was thought that such an attempt, 

 although desirable, would likely result in a separation of the air- 

 craft, with subsequent abortion of the primary mission. 



"Visual observation of the seeded area showed a pronounced 

 modification of the cloud deck seeded. No organized trough was 

 observed; rather, the overcast previously observed appeared as 

 an area of widely scattered snow clouds. The disturbed area cov- 

 ered perhaps 300 square miles. No convective activity was seen 

 to follow the seeding process at any time during the mission." 



