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Types of Precipitation There Are Many Forms of Precipitation to Be Found in Every Climate

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Types of Precipitation There Are Many Forms of Precipitation to Be Found in Every Climate TYPES OF PRECIPITATION THERE ARE MANY FORMS OF PRECIPITATION TO BE FOUND IN EVERY CLIMATE. EVERY CLIMATE WILL HAVE A WIDE RANGE OF PRECIPITATION THROUGHOUT THE YEAR. DEPENDING ON THE SEASON, THE TYPES OF PRECIPITATION THAT WE NOTICE WILL DIFFER. GLOBAL PRECIPITATION DISTRIBUTION Global Precipitation Precipitation averages just about 1 meter per year over Earth but, like wealth, varies widely from place to place and over time. Rainfall is generally greatest near the Equator where the air rises, small in the subtropics where the air sinks, and tiny in the polar regions where the frigid air has a tiny vapor capacity. The next slide shows how precipitation varies over the year, as the main rain belts follow the Sun north and south with the seasons. GLOBAL PRECIPITATION PATTERN U.S. PRECIPITATION DISTRIBUTION RAIN • THIS IS A LIQUID PRECIPITATION THAT FALLS TO THE SURFACE IN DROPLETS THAT ARE GREATER THAN 0.5 MM IN DIAMETER. • RAIN FALLS IN DIFFERENT INTENSITIES. THE INTENSITY IS CLASSIFIED AS LIGHT, MODERATE, OR HEAVY AND IS DETERMINED BY THE ACCUMULATION OR AMOUNT THAT FALLS OVER A GIVEN TIME. RAINFALL PATTERNS IN THE US SNOW • SNOW FORMS WHEN ICE CRYSTALS COMBINE INTO FLAKES. • SNOW USUALLY FORMS WHEN THE TEMPERATURES ARE BELOW FREEZING. • SNOW ONLY REACHES THE SURFACE WHEN THE ENTIRE TEMPERATURE OF THE TROPOSPHERE IS AT OR BELOW FREEZING. • SNOW INTENSITY IS LIGHT, MODERATE, HEAVY, AND IS CATEGORIZED AS SUCH DEPENDING ON THE ACCUMULATION OVER A GIVEN TIME. U.S. ANNUAL SNOWFALL A blizzard (heavy snowstorm with cold temperatures and strong winds) with huge snowflakes, Upper Saddle River, NJ LAKE EFFECT SNOW LAKE EFFECT SNOW LAKE EFFECT SNOW In the Good Old Days When Winter Was Really Winter Great Lakes Effect Snowstorm, New York State, January 2007 SNOW PELLETS • SNOW PELLETS ARE PRECIPITATION THAT OCCURS WHEN COOLED WATER FREEZES ON ICE CRYSTALS OR SNOW FLAKES. • SNOW PELLETS CAN ALSO OCCUR WHEN SNOWFLAKES MELT AND THEN REFREEZE AS THEY FALL. • SNOW PELLETS ARE MANY TIMES CALLED SLEET, HAIL, AND SNOW. • THEY WILL BOUNCE OFF OF OBJECTS AND ARE WHITER IN APPEARANCE THAN SLEET. SNOW GRAINS • THESE ARE SMALL GRAINS OF ICE. • ACCUMULATION IS NOT USUAL WITH SNOW GRAINS. • THEY ARE THE SOLID EQUIVALENT TO RAIN DRIZZLE. ICE CRYSTALS • MANY TIMES ICE CRYSTALS ARE ALSO KNOWN AS DIAMOND DUST. • THEY FLOAT IN THE WIND AND ARE SMALL ICE CRYSTALS. SLEET • ICE PELLETS, ALSO KNOWN AS SLEET, ARE RAINDROPS THAT HAVE FROZEN. • THE SNOW FALLS THROUGH A LAYER OF AIR THAT IS A LITTLE ABOVE FREEZING AND THE SNOW IS PARTIALLY MELTED. • THE LOWEST LAYER OF THE TROPOSPHERE WILL BE BELOW FREEZING WHEN SLEET IS FALLING AND THIS ALLOWS THE DROPS THE COMPLETELY FREEZE. SLEET HAIL • THIS IS DENSE PRECIPITATION THAT IS ICE AND IS AT LEAST 5 MM IN DIAMETER. • THE WATER THAT IS IN THE ATMOSPHERE FREEZES AND STICKS TO THE EMBRYO HAIL STONE. • THERE IS SOFT HAIL AND HARD HAIL THAT CAN FALL. • HARD HAIL • OCCURS WHEN LIQUID WATER DROPS FREEZE ON THE OUTER EDGES OF HAILSTONES AFTER THE OUTER EDGE IS ABOVE FREEZING. THE FREEZING OF SUPER COOLED WATER RELEASES LATENT HEAT AND THIS CAN RESULT IN THE OUTER EDGE OF THE HAILSTONE WARMING ABOVE FREEZING. THEN THE WATER REFREEZES CREATING SOLID ICE. • HAIL WILL COMMONLY HAVE SOFT ICE AND HARD ICE LAYERS WHEN IT IS SLICED IPEN. • SOFT HAIL • MORE WHITE AND LESS DENSE SINCE IT HAS AIR BUBBLES • OCCURS WHEN HAIL GROWS AT A TEMPERATURE BELOW FREEZING BY ICE CRYSTALS AND SMALL SUPER COOLED WATER AND CLOUD DROPLETS MERGING ONTO THE HAILSTONE. HAIL HAIL Biggest hailstone ever recorded=17cm - Yikes!!! HAIL The largest recorded hailstone in the United States by diameter (8 inches) and weight (1.93 pounds) fell in Vivian, South Dakota on July 23, 2010. FREEZING RAIN • LIQUID PRECIPITATION THAT REACHES THE SURFACE IN THE FORM OF DROPS THAT ARE GREATER THAN 0.5 MM IN DIAMETER. • THE DROPS THEN FREEZE ON THE EARTH’S SURFACE. DRIZZLE • LIQUID PRECIPITATION OR RAIN THAT REACHES THE SURFACE IN THE FORM OF DROPS THAT ARE LESS THAN 0.5 MM IN DIAMETER. FREEZING DRIZZLE • LIQUID PRECIPITATION OR RAIN THAT REACHES THE SURFACE IN THE FORM OF DROPS THAT ARE LESS THAN 0.5 MM IN DIAMETER. • THE DROPS THEN FREEZE ON THE EARTH’S SURFACE. MIXED PRECIPITATION • THE TYPES OF PRECIPITATION DO NOT NECESSARILY MEAN THAT THERE IS ONLY ONE FORM OF PRECIPITATION FALLING. • MIXED PRECIPITATION IS WHEN TWO OR MORE TYPES OF PRECIPITATION FALL AT ONCE. • THIS IS MORE COMMON IN CLIMATES WHERE WEATHER SHIFTS ARE MUCH MORE EXTREME. • EXAMPLES: SLEET AND SNOW IN THE WINTER, RAIL AND HAIL IN THE SPRING, ETC. FREEZING RAIN AND SLEET.
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