Here, descending air suppresses cloud formation, creating a bizarrely serene circle, typically 20--40 miles in diameter, surrounded by the raging storm.

在这里，下降的空气抑制了云的形成，形成了一个奇异的宁静圆圈，通常直径为20--40英里，周围环绕着肆虐的风暴。

Warm air can hold onto more moisture than cold, so any moisture in this descending  air remains locked in, and won't produce rain.

暖空气比冷空气能容纳更多的水分，因此下降空气中的任何水分都会被锁在里面，不会产生雨。