Over the past few months, we’ve covered some of the history of the American military efforts to control the weather. We’ve covered Project Cirrus of the 1940s, and the multi-decade weather modification project known as Project Stormfury

In those cases, there were many scientists arguing that the Projects were not a success, and any perceived “successes” were nothing more than circumstantial. The 1970s was a time when many such “fringe” government projects were debated throughout the scientific community and debunked.

However, there is one weather modification project that can’t be swept away or dismissed quite so easily. That project was known as Project Popeye, and it involved cloud seeding in Laos throughout the late 1960’s in an effort to extend the Vietnamese rainy season. If the project mission was successful, it would hamper North Vietnamese vehicular movements on the ground, and slow or eliminate the movement of enemy resources through the Se Kong area.

The first 50 case samples of the Operation Popeye experiment began in September of 1966 and lasted for about one month. According to declassified project documents, scientists found that with the 56 samples attempted, over 85 percent of the weather modification efforts were deemed “successful”, in that the weather responded to the cloud seeding in a predictable manner. (1)

In fact, the Air Force considered the project so successful that COMUSMACV proceeded to implement the Project Popeye technique as a full-scale effort across the Vietnam theater. (2)











Operation Popeye Revealed

Once the technique was implemented on a wider scale, the efforts to manipulate weather took place not only over Laos, but extended into western North Vietnam, the A Shau Valley of South Vietnam, as well as Northeastern Cambodia starting in 1972. By July 5th, 1972, due to the details surrounding weather modification being leaked to the public, the efforts to create rain officially ended. (3)

This Operation is not the delusional ramblings of conspiracy theorists – it really happened and is well-documented. In fact, in “The Pentagon Papers,” by Mike Gravel, confirmed the operation in its description of “LAOS OPERATIONS”, where it stated:

“LAOS OPERATIONS–Continue as at present plus Operation POP EYE to reduce trafficability along infiltration routes. Authority/Policy Changes–Authorization required to implement operational phase of weather modification process previously successfully tested and evaluated in same area.” (4)

While the Air Force leadership in charge of operations in Vietnam considered weather modification to be just one more important tool in the entire arsenal at the military’s disposal, the moment Jack Anderson released details about the operation (using the secret 1967 memo with the excerpt quoted above) in the Washington Post on March 18, 1971, things took a turn for the worst.