Answer: Jet streak.
Explanation:
Jet streak is the part of the general jet stream through which wind from one end of the jet core to another flows stronger compared to other areas down the jet stream. The portion where winds accelerates to the upstream side of the jet streak is known as "the entrance region of the jet stream." Jet streaks are the results of large and low level temperature gradient during frosty and cool weather in which there is large temperature differences between the polar and tropical regions.
