Veering Wind - This is a way to describe how the wind direction changes with respect to height. A veering wind means that the wind direction is turning in a clockwise sense with increasing height. An example of a veering wind is when the wind at the surface is from the south and a few thousand feet above the surface the wind direction is from the west. The opposite of a veering wind is a backing wind.

Santa Ana Winds - A persistent wind that blows from east to west across southern California. The most common time of the year to see Santa Ana winds is from September to May. During this time of year a high pressure system periodically sets up over Nevada and Utah. The flow around the high induces the east winds that flow down the mountains into southern California. These dry, warm winds are notorious for creating ideal conditions for fires to start and spread.

Deposition - The process where water turns directly from vapor to ice, without first becoming liquid. A common instance of deposition is when frost forms on the grass during cold mornings.

Doppler Effect - The shift in frequency that occurs when an object goes from moving towards an observer to away from an observer. Everyone has heard this when a police car drives by. As the police car is approaching, the siren will have a high pitch. Then when the police car begins moving away from you the pitch of the siren lowers. This effect is what weather radars use to calculate velocity.

Mammatus Clouds - Cloud cover that has numerous rounded, smooth, sack-like protrusions hanging from the underside. Mammatus clouds are most commonly found in an anvil of a thunderstorm. Mammatus clouds can accompany severe thunderstorms, but they also occur often with non-severe thunderstorm activity.

El Nino - An anomalous warming of ocean waters in the east central equatorial Pacific. El Nino events occur every two to seven years and have local as well as global impacts. Nutrient deficient waters cripple the fishing industry off the coast of western South America during El Ninos, while global weather patterns can be significantly altered due to the presence of an El Nino.

Haze - Haze can be composed of fine dust, smoke, salt particles, or atmospheric pollutants. These particles become coated with water droplets giving them an even larger bearing on sky conditions and visibility. Haze gives the sky a milky tone due to the veil it puts between us and the sun.