A lot of the information is cloud sourced (such as the weather). But Shoni could also be time based. The guy in the pic caught his at 13:25 apparently so I'm not sure if it's possible but maybe it's only moochable during a certain window? Or maybe the other person who caught it did so just as blizzard weather ended and it's not moochable outside blizzard weather? Either way it's sounding more difficult and this weather is so rare it's a bit of a nightmare