What happens right before a tornado?

Related questions

1. What is tornado season?
2. What causes a tornado to touch the ground?
3. Is a tornado a tornado if it doesn't touch the ground?
4. Do squall lines produce tornadoes?
5. Can thunder kill you in your house?
6. Does it get calm before a tornado?
7. What does snow squall warning mean?
8. What are weather squalls?
9. What year had the most tornadoes?
10. What state has the most tornadoes 2018?

Tags

1. #clouds
2. #warning
3. #signs
4. #there
5. #cloud
6. #approaching
7. #atmospheric
8. #greenish
9. #become
10. #tornado
11. #strikes
12. #often
13. #several
14. #debris
15. #before
16. #arrival
17. #still
18. #precipitate