Which jetstream is not associated with a frontal system?

The subtropical jetstream is recognized as a high-altitude, fast-moving ribbon of air that flows in the upper troposphere, generally found around 30 degrees latitude in both hemispheres. It forms in the region between the tropical and polar air masses, primarily due to the temperature differences between these two areas. The subtropical jetstream is not typically associated with frontal systems; instead, it exists in a relatively stable environment characterized by warm air to the south and colder air to the north, where frontal lifting is less prevalent compared to other types of jetstreams.

In contrast, the polar jetstream, split jetstream, and equatorial jetstream are more frequently linked with the movement of fronts and associated weather systems. For example, the polar jetstream is located at higher latitudes and often drives mid-latitude cyclones, leading to more dynamic weather patterns, while the split jetstream occurs when the jetstream divides into two distinct branches, frequently interacting with frontal systems. The equatorial jetstream, though primarily a feature of the tropics, can also influence weather patterns associated with the Intertropical Convergence Zone (ITCZ), correlating it with fronts under specific conditions.

Understanding the characteristics of these jetstreams helps differentiate their roles in