AVALANCHE 
    An event where a mass of snow, rock, and ice falls down 
    a mountain. Usually it refers to a snow avalanche. In the 
    U.S. the term snow slide is commonly used to mean a 
    snow avalanche. 

BLIZZARD 
    A storm that produces heavy blinding snow, near zero visibility, 
    deep drifts and dangerous wind chill. 

DUST STORM 
    A strong wind storm that fills the air with thick dust. Visibility 
    can be reduced to 1/2 mile or less. 

EARTHQUAKE 
    The shaking, rolling or sudden shock of the earth’s surface. 
    Earthquakes happen along fault lines in the earth’s crust. 

EYE 
    A name used for the center of a hurricane. It is the point where 
    the storm rotates in a counter-clockwise direction. In the eye 
    of a hurricane, the winds do not blow. 

FAULT LINES 
    Breaks in the Earth's crust where pressure is created as the two 
    sides of the break rub against each other. This pressure is 
    sometimes released in an earthquake. 

FLASH FLOOD 
    A dangerous and sudden flood that threatens lives and property 
    and usually occurs after heavy rain. May also occur after an ice 
    jam breaks up or after a dam breaks. 

FREEZING DRIZZLE or (FREEZING RAIN)  
    Rain that freezes when it hits the ground, creating a coating of ice 
    on roads and walkways. 

FUNNEL CLOUD 
     A rotating, visible extension of cloud, with the top attached to 
     the cloud but not touching the ground. 

HABOOB 
     A violent dust storm or sand storm found in northern Africa, 
     India, or the southwestern United States. 

HAIL 
     Rain that has been frozen many times on its way to the 
     ground, creating a lumpy ball of ice. 

HEAVY SURF 
     Large waves breaking on the shore or near the shore, 
     caused from storm swells created by a distant storm. 

HURRICANE  
     A dangerous tropical cyclone with winds speeds of 74 mph, or 
     higher. Also known as a typhoon in the western Pacific Ocean. 

ICE STORM 
     Freezing rain that creates a dangerous sheet of ice that is 
     1/4 inch thick or greater. 

LIGHTNING 
     A sudden visible flash of energy and light caused by electrical 
     discharges during a thunderstorm. 

RICHTER SCALE 
     The scale used by scientists to measure the intensity of an earthquake. 
     It was created by Charles F. Richter in 1935. 

SEVERE THUNDERSTORM 
     A thunderstorm that produces either of the following: damaging 
     winds of 58 miles an hour or greater, hail 3/4 of an inch in 
     diameter or larger, or a tornado. Severe thunderstorms can 
     result in the loss of life and property. 

SLEET 
     Rain that turns to ice pellets before reaching the ground. Sleet also 
     causes roads to freeze and become slippery. 

STORM SWELL 
     A long, often massive and crestless wave or succession of waves 
     that are caused by hurricanes. 

TORNADO 
     A wild, rotating column of air, usually attached to a cloud at 
     the top and touching the ground. It nearly always starts off 
     as a funnel cloud and may be accompanied by a loud roaring 
     noise, like a train coming. 

TROPICAL DISTURBANCE  
     A powerful storm that forms over water in the tropics or 
     subtropics and holds its strength for 24 hours or more. As it 
     gains power, it may become a tropical wave, tropical depression, 
     tropical storm, or hurricane. 

TSUNAMI 
    An ocean wave produced by an event at sea, like an earthquake, 
    landslide, or volcanic eruption. These waves may reach enormous 
    size and have been known to travel across entire oceans. 

WATERSPOUT 
     A wild, rotating column of air over a body of water, usually 
     attached to a cloud at the top and reaching the water. 

WIND CHILL 
     An apparent temperature that describes the combined effect of 
     wind and low air temperatures on exposed skin.