I read about these in a few places,
This article states:
Powers of Longitudinal Wave Interferometers
1 - influence and control the weather,
2 - deviate the giant jetstreams of the upper atmosphere,
cited by Tom Bearden at Cheniere.Org
This article states:
The talk was given in the mid-1980s and since then, the technology has been developed into more rigorous longitudinal EM wave interferometry, which is the exact nature of those earlier weather engineering weapons.
So, do these weapons actually exist? (or are they just theoretical)
And have they ever been used?