chaseit
Storm types#tornado#damage

Tornado (and the EF scale)

At a glance

A violently rotating column of air in contact with both the ground and the cloud base. Rated after the fact by the damage they cause, on the Enhanced Fujita (EF) scale from EF0 to EF5.

Deep dive

Tornadoes are classified by damage, not measured wind:

  • EF0 — 65–85 mph (UK: common; 30+/yr climatologically).
  • EF1 — 86–110 mph (a handful per year in UK).
  • EF2 — 111–135 mph (rare in UK; ~1 per decade is typical).
  • EF3+ — historic; e.g. Birmingham 2005.

Most UK tornadoes are non-supercell types (cold-core, waterspout-origin, gust front spin-ups). Supercell tornadoes are the minority but produce the strongest rated events here.

TORRO runs the UK verification system. See case-archive for the chaseit reconciliation workflow.