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<br />A high. thin cloud produces smaller drops, while the low <br />based, thicker cloud produces both small and large drop- <br />lets. <br /> <br />Typical rain drop sizes <br /> <br />1 1 <br />i2 16 <br />. . <br /> <br />tHigh, Thin <br />. Clouds <br /> <br />3 <br />32 <br />o <br /> <br />1 <br />l' <br />o <br /> <br />.1. <br />32 <br />o <br /> <br />1 <br /> <br />t <br /> <br />Low Based, Thick, Stron~ Updraft <br /> <br />r <br /> <br />The air between cloud base and the ground is drier, less <br />humid, than the air in the cloud. <br /> <br />The smaller the raindrop initially the more likely it is <br />to evaporate completely before it reaches the ground. <br /> <br />For the high clouds, the rain drops are small and they have <br />great distances to fall (sometimes up to 3 miles). Conse- <br />quently, a rain shower which doesn't reach the ground is <br />frequently observed from such high clouds. <br /> <br />In general, it is most difficult for rain to reach the sur- <br />face if the cloud bases are more than 12,000 feet above the <br />ground. <br /> <br />Fewer raindrops reach the ground as the fall distance <br />increases because more time is available for evaporation. <br /> <br />34 <br />