TYPES OF THERE ARE MANY FORMS OF PRECIPITATION TO BE FOUND IN EVERY .

EVERY CLIMATE WILL HAVE A WIDE RANGE OF PRECIPITATION THROUGHOUT THE YEAR.

DEPENDING ON THE , 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 belts follow the Sun north and south with the . 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 FORMS WHEN 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 (heavy snowstorm with 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 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 OR SNOW FLAKES. • SNOW PELLETS CAN ALSO OCCUR WHEN SNOWFLAKES MELT AND THEN REFREEZE AS THEY FALL. • SNOW PELLETS ARE MANY TIMES CALLED , , AND SNOW. • THEY WILL BOUNCE OFF OF OBJECTS AND ARE WHITER IN APPEARANCE THAN SLEET. • THESE ARE SMALL GRAINS OF ICE. • ACCUMULATION IS NOT USUAL WITH SNOW GRAINS. • THEY ARE THE SOLID EQUIVALENT TO RAIN . ICE CRYSTALS

• MANY TIMES ICE CRYSTALS ARE ALSO KNOWN AS . • THEY FLOAT IN THE WIND AND ARE SMALL ICE CRYSTALS. SLEET

• , 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 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.

• 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.

• 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 WHERE SHIFTS ARE MUCH MORE EXTREME. • EXAMPLES: SLEET AND SNOW IN THE WINTER, RAIL AND HAIL IN THE , ETC.

FREEZING RAIN AND SLEET