What phenomenon describes a strong downward and outward force of air resulting from thunderstorms?

The phenomenon that describes a strong downward and outward force of air resulting from thunderstorms is a microburst. Microbursts are intense small-scale downdrafts that occur in thunderstorms and can have winds that exceed 100 mph. These downdrafts result from cool, moist air descending rapidly during a storm, ultimately spreading out once they hit the ground, leading to damaging winds in a localized area. This characteristic makes microbursts particularly hazardous for aviation, as they can create sudden and severe wind shear conditions.

In contrast, a jet stream refers to high-altitude, fast-moving air currents that typically influence larger weather patterns but are not directly linked to the localized downward force of air. Tornadoes involve rotating columns of air associated with severe thunderstorms and can produce extreme wind speeds, but they are not defined specifically by the downward and outward force in the context of microbursts. An updraft, on the other hand, describes the upward movement of air within a thunderstorm, which is quite the opposite of the downward force characteristic of microbursts. Thus, the defining action of a microburst captures the essence of the phenomenon described in the question.