xkcd #3267: Types of Tornado Alert
Title text:
I hate the unearthly sound my phone makes when the weather service issues a tornado harbinger.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3267/
Heisenberg's Tornado Principle: you can know tornado's position and velocity within error margins. i.e. you can know a tornado's location, but when you go to check it out it's somewhere else.