Aviation Weather: Wind Dynamics and Air Masses

These flashcards cover essential vocabulary and concepts related to aviation weather, focusing on wind dynamics, atmospheric stability, and air masses.

Vector Quantity

A quantity that has both magnitude (speed) and direction, such as wind.

Pressure Gradient Force (PGF)

The initial force that sets air in motion, acting from high to low pressure.

Coriolis Force

An apparent force caused by Earth's rotation that deflects moving air, right in the Northern Hemisphere and left in the Southern Hemisphere.

Frictional Force

The force that decreases wind speed and alters direction as air interacts with the Earth's surface.

Geostrophic Wind

Wind that results from the balance between the pressure gradient force and the Coriolis force, flowing parallel to isobars.

Anemometer

An instrument that measures wind speed by rotating cups, not needing to be pointed into the wind.

Boundary Layer

The lowest part of the troposphere where friction affects wind behavior, leading to variations in speed and direction.

Sustained Speed

The average wind speed measured over a period of two minutes.

Squall

A sudden increase in wind speed of at least 16 knots, sustained for 1 minute at 22 knots or more.

Dewpoint

The temperature at which air must be cooled for saturation to occur.

Relative Humidity

The amount of water vapor present in the air compared to the maximum amount the air can hold at that temperature.

Lake Effect Snow

Snowfall that occurs when cold air moves over warmer lakes, picking up moisture.

Chinook Winds

Warm, dry winds that descend the eastern slopes of the Rocky Mountains.

Atmospheric Stability

Determined by comparing the Environmental Lapse Rate (ELR) to the Dry Adiabatic Lapse Rate (DALR).

Lenticular Clouds

Stationary clouds that indicate mountain waves and potential turbulence.

METAR

A standardized format for reporting current weather information, including wind data.

Contrail

A visible trail of condensed water vapor created by an aircraft at high altitudes.