What term describes a thin, sinuous tornado often seen as it weakens?

A thin, sinuous tornado often seen as it weakens is called a rope tornado.

The name describes appearance rather than a separate meteorological species. During the dissipating, or “roping out,” stage, the visible condensation funnel narrows, stretches, tilts, and may twist into irregular shapes. Conservation of angular momentum helps explain why the circulation can become narrower as it weakens.

Rope tornadoes are often associated with a tornado’s final stage, but shape alone does not prove that a tornado is weak. Some tornadoes begin narrow, and a rope-shaped funnel can still produce dangerous winds and damage. Conversely, a broad wedge-shaped tornado is not automatically stronger merely because it looks larger.

The distractors describe different appearances or structures. A stovepipe tornado has a relatively cylindrical profile, a wedge is unusually broad, and a satellite tornado is a separate tornado rotating near a primary one. “Rope tornado” is the standard term for the thin, winding appearance described here.