Name: ______ws#______PRECIPITATION: Science/Phipps/Block # ______Date: ______PART OF THE WATER CYCLE

Clouds that Produce Precipitation Clouds that Do not Produce Precipitation

Precipitation Notes

COLD AIR

WARM AIR

COLD AIR

FREEZING HAIL RAIN RAIN SLEET SNOW Updrafts Snow melts as Snow melts, Snow melts, Snow falls cause it reaches hits cold air , refreezes through frozen warmer air freezes when into ice cold air pellets it hits cold as it falls, to refreeze surface never melts as they rise and fall

RAIN By far the most common form of precipitation, rain is a drop of liquid water that has become too heavy to remain suspended in a cloud. The rain that falls may have started as an ice crystal and as it falls, it melts. This may not be true in the Tropics, however, where the rain is water that has remained in its liquid state from the cloud to the ground. Even in the summer, the storms of the middle latitudes often produce rain that began as an ice crystal because the upper parts of the troposphere are cold. Raindrops are round, with a somewhat flat bottom. Raindrops range in size from about two-hundredths of an inch, (0.02 inch) to roughly a quarter of an inch, at which point they begin breaking up into smaller drops. The typical raindrop is about a 16th of an inch. The fine drifty stuff that falls from the sky in drops of less than .02 of an inch is called drizzle. FREEZING RAIN Freezing rain is super-cooled raindrops that freeze on impact with cold surfaces. Storms that produce freezing rain, called ice storms, are some of the most dangerous and damaging of all weather events. The weight of the accumulating ice crushes trees and snaps electrical power lines. Layered by nearly invisible ice, roadways become extremely hazardous. SLEET Falling snow may partially melt and then refreeze into a frozen raindrop before it reaches the ground. These ice pellets, easily visible white stuff that bounces off the ground under these conditions are called sleet. Sleet forms under conditions that are similar to those that produce freezing rain. The difference is that the lower layer of cold air is deeper so that the partially melted snowflake or cold raindrop has time to freeze into an ice pellet before reaching the ground. Sleet can accumulate massive layers of ice, but its effect is different than the ice layers formed by freezing rain. The pellets do not accumulate on trees and power lines like freezing rain, and because it is formed by pellets, the ice layers of sleet are less slippery. SNOW Snowflakes are collections of solid ice crystals that assemble themselves as they fall through a cloud. Much precipitation forms firs as ice crystals and then snowflakes, although if they melt, then they are considered rain. Snowflakes come in different shapes and sizes. HAIL Hail is a large frozen raindrop that is formed inside the enormous cloud of an intense thunderstorm. The cloud contains a powerful updraft that keeps the frozen raindrop from falling. Super-cooled droplets freeze onto the ice, forming frozen layers. Eventually, the hailstone is too heavy for the updraft to support any longer, and it falls to the ground. Hailstones range in size from two-tenths of an inch (0.20), to the size of softballs.

All precipitation is tricky to measure, because of winds. Rain gauges are straight-sized tubes or buckets that can be used to collect liquid precipitation. Snow gauges are similar, but have a flat surface.

Matching: Precipitation __D_1. large frozen raindrop formed inside an enormous cloud A. rain __A_2. the most common form of precipitation B. snow _E _3. super cooled raindrops that freeze on impact C. sleet _B__4. ice crystals that assemble themselves as they fall through a cloud D. hail _C_5. falling snow that melts and refreezes into a frozen raindrop before E. freezing rain it hits the ground

WATER CYCLE REVIEW Label the following diagram using the word bank: condensation respiration evaporation transpiration precipitation

condensation

evaporation precipitation

transpiration respiration

True or False: _T__1. As water vapor rises in the troposphere is cools. _F__2. Warm water vapor rises in the troposphere because it becomes less dense. _F__3. Water vapor moves up in the air and forms clouds through transpiration. _F__4. Animals give off water vapor through the process of photosynthesis. _F__5. Transpiration occurs in animals. _T__6. Water travels in an endless cycle. _F__7. Dew is an example of evaporation. _T__8. The formation of a cloud is due to condensation. _F__9. Evaporation is the process of a gas changing into a liquid. _T__10. Condensation is the process of a gas changing into a liquid.