What is Tornado Vortex Signature?

A tornado vortex signature (TVS) is a specific pattern detected by Doppler radar that indicates strong, concentrated rotation within a thunderstorm. It appears when inbound and outbound wind velocities are tightly packed together, signaling the presence of a mesocyclone or an actual tornado. The TVS is an essential tool in tornado detection and forecasting, helping meteorologists issue timely warnings.

A TVS is typically associated with supercell thunderstorms, which are the most common producers of violent tornadoes. When radar detects a TVS, it suggests that a tornado may be forming or is already on the ground. However, not all TVS signals indicate an actual tornado; some may be strong rotating updrafts that never touch down.

Meteorologists use the TVS to assess the potential intensity of a tornado by analyzing the rotational velocity and the size of the circulation. The more defined and persistent the TVS, the higher the likelihood of a tornado. In many cases, a TVS appears on radar before a tornado is confirmed visually or by storm spotters, making it a critical tool for early warnings.

Because of its importance in tornado detection, the National Weather Service (NWS) and other meteorological agencies closely monitor TVS patterns, combining them with other storm data to improve the accuracy of tornado warnings and reduce false alarms.