Does anyone know why the Tendo Path of Pain apparently had control over the weather at some point? After he detects Jiraiya the power isn't ever mentioned again. The two shinobi Jiraiya captures talk about the weather as if "Lord Pain" prevents it, but in the translation I read, Pain says "Someone has circumvented my rain," as if he causes it. Regardless of whether Pain controls the rain, is there a plausible explanation for how this could be?
This is caused by one of the techniques pain Nagato uses the Rain tiger at will technique. This technique infused with chakra causes the user to sense outsiders chakra
when guarding Amegakure Nagato was able to use the Rain Tiger at Will Technique to make it rain. This rain was infused with his chakra and as such, served as a large-scale sensory technique for him in his village.
The description of this technique would be
A perception ninjutsu, allowing one to freely manipulate rain infused with the user's own chakra. The rain falls from rain clouds, formed with Pain's own chakra. During this technique, the falling raindrops are closely linked to Pain's senses. When the rain is obstructed by a chakra belonging to someone not of the village, the existence of the intruder can be detected. The rain will keep on falling until Pain uses the seal to cancel it. Pain made it rain every Sunday in Amegakure, or whenever he had to leave the village.