Answer: 120 - 240 kilometers per hour
Step-by-step explanation:
Jet streams are narrow, fast flowing, air currents that are in the atmospheres of certain planets, which includes the Earth. Jet streams are air currents that are placed very high above the Earth and form where there are big differences in temperature in the atmosphere.
The jet stream has winds that blow up to 120 - 240 kilometers per hour which can greatly influence the impact of weather patterns over a continent.