Since 2012 the radar has shown several times strange images of what appear to be a spiral vortex. And it happens every time when a UFO appears above a volcano, especially the Popocatépetl Volcano.
It happened again on October 16, 27 and 28 and on December 28, 2015 and on March 1, 2 and 5 in 2016.
Jorge Tokunaga who registered the spiral vortex made a statement that a spiral vortex appeared after a UFO was seen above a volcano. Surprisingly his images of the spiral vortex were deleted from Internet as well as the images were deleted from the weather system.
After they cleaned up the radar and configured it again, the strange shape of energy was still there.
Here is the investigation with Fernando Correa.