Usually means fair weather. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stratus Clouds Layers of flat, sheet like gray clouds that are usually found at relatively low heights. Usually means precipitation. Weather Clouds Precipitation Precipitation - Water that falls to the earth from the atmosphere. May be in liquid or solid form.
Precipitation begins when the air cools and the water in the air condenses.
Snow - An ice crystal falls and accumulates more ice on it from other ice crystals and from the water vapor in the cloud, which forms a snowflake. When the air is freezing all the way to the ground, snow will fall. When the ice crystals pass through a layer of warmer air, they melt, losing the characteristic crystal shape of snowflakes, and become drops of water. When the drops of water pass through a layer of freezing air near the ground, they re-freeze into sleet. Sleet is irregular in shape because the water re-freezes as it falls and the force of the air changes the shape of the drop.