To form a tornado, cold air must sit above warm and moist air, and the wind needs to go in different directions at different heights, creating shear forces.

形成龙卷风，寒冷的空气必须处在暖湿的空气上部，而风应该在不同高度向不同的方向运动，以此创造出剪切力。

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Clouds and storms are driven by warm, moist air that rises up off Earth's surface, then cools and condenses.

云朵和暴风雨是温暖、潮湿的空气上升，离开地球表面，然后遇冷并凝结而成的。

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The influx of cold air on top of warm, moist air favours the sort of deep convection that creates powerful storms, turning moisture in the air into water on the ground very efficiently.

寒冷的空气流入的温暖空气的顶端，潮湿的空气形成的深对流造成强烈的风暴，大气中的水分高效的形成降水于地面。

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The thunderstorm developed in an area where warm moist air rose into cooler air.

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Tangential entries cause the warm moist air to spin as it rises forming an anchored convective vortex.

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Tornadoes are most likely when exceptionally cold, dry air plunges south to violently clash with warm, moist air originating in the Gulf of Mexico.

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