What does a TAF that includes "TS" indicate?

A TAF that includes "TS" indicates thunderstorms. In aviation weather reports, "TS" is a standardized meteorological code used to denote the presence of thunderstorms expected within the forecast period. These thunderstorms can significantly affect flight operations due to turbulence, lightning, and potential for severe weather conditions like hail or strong winds. Understanding the implications of "TS" in a TAF is crucial for pilots and air traffic controllers as it helps them assess safety and manage flight planning effectively.

The other terms mentioned in the options do not have the same recognized meaning in TAF reporting. Tornadoes, while severe weather phenomena associated with thunderstorms, are not indicated by "TS" in a TAF. Tempest conditions and transitional storms are not defined standard terms in aviation meteorology, further validating that "TS" specifically points to thunderstorms.