1. Supercells and Tornadoes
What we’ll cover:
Thunderstorm types
Supercell characteristics
Tornado Genesis Theory
Storm Structure

2. Thunderstorm Categories
Single Cell
Multicell cluster
Multicell line
Supercell*

3. Single Cell Storms Typically last 20-30 minutes Typically not severe
Cells producing a brief severe event are known as ‘pulse severe’ storms
Usually disorganized
Hard to forecast

4. Multicell cluster Most common type
Each cell lasts about 20 minutes; cluster may last for several hours
Consists of a group of cells moving along as one unit
Each cell is usually at a different phase in it’s life cycle
Mature cells found at center, dissipating found downwind
Can produce moderate sized hail, flash floods and brief tornadoes

5. Multicell (Squall) Line
Long line of storms with a continuous well-developed gust front at the leading edge of the line
Can last for up to 12 hours
Produce hail up to golf-ball size, heavy rainfall, and weak tornadoes, but they are best known for strong downdrafts
Can also produce bow echoes

6. Supercell
Definition
a supercell is a convective storm that possesses a deep, persistent mesocyclone

7. Mesocyclones Definition
A cyclonically rotating vortex, around 2–10 km in diameter, embedded within a convective storm

8. Supercell Highly organized thunderstorm
A supercell is similar to the single-cell storm because they both have one main updraft
updraft is extremely strong, reaching estimated speeds of miles per hour
main characteristic which sets the supercell apart from the other thunderstorm types is the presence of rotation

9. Supercell
Produces giant hail more than 2 inches in diameter, strong downbursts of 80 miles an hour or more, and strong to violent tornadoes.
Wind shear contributes to the severe nature of the storm

10. Wind Shear
Two types
Speed Shear
Directional Shear

11. Supercell Categories
Three standard types (though hybrids definitely occur)
High Precipitation (HP)
Classic
Low Precipitation (LP)

12. HP Supercells Outflow (downdraft) dominant supercells
Responsible for rain-wrapped tornadoes
produce extreme and prolonged downburst events, serious flash flooding, and very large damaging hail events
Most dangerous of all supercells

13. HP Supercell

14. Classic Supercells
Visually well established and separate updraft and downdraft (precip core) regions

15. Classic Supercell

16. LP Supercells Hard or impossible to identify on radar
Can produce large hail, weak to occasional strong tornadoes, weak to moderate intensity downdrafts, little rain

17. LP Supercell

18. Tornadogenesis

19. Tornadogenesis

20. Tornadogenesis

21. Chaser Terminology Bears cage CG Barber pole Beavers tail Cigar rolls
Cored
Sharks teeth
Yahoo
Roll cloud
Whales mouth
Shelf cloud
Notch
RFD cut
Scud
HDT’s
Anvil splash
Gustnadoes
Dome
Collar cloud
Upside down Wedding cake
Hail roar

22. Roll Cloud

23. Shelf Cloud

24. Whales Mouth

25. Upside Down Wedding Cake

26. Beaver Tail

27. Collar Cloud

28. Anvil (back)

29. Anvil (front)

30. Tornado

31. Tornado

32. Tornado

33. Tornado

34. Damage

35. Supercells

36. Supercells

37. Supercells

38. Supercells

39. Supercells

40. Supercells

41. Supercells

42. Supercells

43. Supercells