La Niña

La Niña is the opposite of El Niño.  La Niña occurs when the ocean current off the coast of Ecuador and Peru cool, causing dramatic changes in weather patterns.

Sleet

Sleet is a frozen or partially frozen raindrop (or a refrozed partially melted snowflake) that will bounce when it hits a hard surface and accumulate as ice.

St. Elmo’s Fire

St. Elmo’s Fire occurs when the masthead of a ship begins to glow due to the buildup of electrical charge. When this happens, lightning can strike within a short time (usually less than 5 minutes).

Low Pressure System

A Low Pressure System is an area of low relative atmospheric pressure that contains convergent (outward flowing) winds and spins the same direction as the earth – counterclockwise in the Northern hemisphere, clockwise in the Southern hemisphere.

High Pressure System

A High Pressure System is an area of high relative atmospheric pressure that spins in the direction opposite of the Earth’s rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere) and contains divergent (inward flowing) winds.

Fujita-Pearson Scale

The Fujita-Pearson Scale is used to measure the intensity of a Tornado based on the amount of destruction the winds may cause dependant on their speed.  Also known as the F Scale, the scale goes from F0 (weak winds, minimal damage) to F5 (violent winds, major damage).

Dew Point

Dew Point (or DewPoint Temperature) measures the amount of moisture in the atmosphere, typically represented as a temperature. The higher the dew point, the more moisture in the air.  When dew point and temperature at equal, the atmosphere is saturated.