Meteorology Flashcards
What is a front?
The boundary between 2 air masses.
What is a cold front and what kind of weather might you expect?
A cold front is a boundary that separates a mass of cold air from a warmer air mass. It typically results in abrupt changes in weather conditions such as strong winds, precipitation, and temperature drops.
What kind of weather is associated with cold fronts?
- Thunderstorms
- Rain showers
- Hail
- Tornadoes
What is a warm front and what kind of weather might you expect?
A warm front is a transition zone where a warm air mass advances and replaces a cooler air mass, producing gradual changes in weather conditions.
What kind of weather is associated with warm fronts?
- Steady precipitation
- Rain
- Snow
- Stratiform clouds
What is an occluded front?
An occluded front occurs when a fast-moving cold front overtakes a slower-moving warm front, creating a complex weather system.
What weather conditions can occluded fronts bring?
- Precipitation
- Clouds
- Thunderstorms
What is a stationary front?
A stationary front occurs when two air masses meet but neither is strong enough to displace the other, leading to prolonged periods of cloudy weather.
What is a dry line?
A boundary that separates a warm, dry air mass from a warm, moist air mass, often triggering thunderstorms.
What is a TROF?
Trough – an elongated line of low pressure.
What is a RIDGE?
An elongated area of high pressure.
What does ISA mean?
International Standard Atmosphere.
What is the standard temperature lapse rate?
-2 degrees/1,000 feet elevation gain.
What is RVR?
Runway Visual Range, used when visibility is 1/2 mile or less, expressed in feet.
What is an isobar?
An equal line of pressure.
What happens if isobars are closely spaced together?
This indicates a tight pressure gradient causing high and gusting winds.
What is an isotherm?
An equal line of temperature.
What is an isotach?
An equal line of wind speed.
What is the primary cause of weather on Earth?
The uneven heating of the atmosphere by the Sun.
What is the Coriolis effect?
A phenomenon causing moving objects to appear to curve due to Earth’s rotation.
What is High Pressure in weather terms?
An area where atmospheric pressure is relatively higher, associated with clear skies and stable weather.
What is low pressure in weather terms?
An area where atmospheric pressure is relatively lower, associated with rising air and unsettled weather.
What part of the atmosphere does most weather occur?
Within the troposphere.
Where is the Earth’s atmosphere thickest?
Near the equator.
What is the Jet Stream?
A narrow, fast-moving stream of air with wind speeds reaching 50 knots or more.
Where is the jet stream typically found?
In breaks in the tropopause.
What is considered stable air?
Air that resists vertical movement and suppresses cloud formation.
What happens when air rises?
It expands due to the decrease in air pressure.
What is a temperature inversion?
A condition where temperature rises as altitude increases, contrary to the normal lapse rate.
How many types of fog are there and what are their characteristics?
3 types of fog: * Radiation: Forms on clear nights when ground cools quickly. * Advection: Warm, moist air moves over a colder surface. * Upslope: Moist air rises over sloping terrain.
How thick must a cloud be for precipitation to form?
4,000 ft.
What are the 3 ingredients of a thunderstorm?
- Uplifting action
- Unstable air
- Moisture
What are the 3 stages of a thunderstorm?
- Cumulus
- Mature
- Dissipating
What are the 2 types of thunderstorms?
- Air Mass
- Steady State
What kind of clouds characterize a thunderstorm?
Cumulonimbus.
What is a squall line?
A line of severe thunderstorms that form along or ahead of a cold front, extending for hundreds of miles.
What are embedded thunderstorms?
Individual thunderstorms embedded within a larger area of widespread precipitation.
What is windshear?
A sudden change in wind speed or direction over a short distance.
Where are the three most common locations you might find windshear?
- Thunderstorms
- Jet streams
- Temperature inversions
What is a microburst?
A strong sudden downdraft reaching up to 6,000 ft per minute.
What is a squall?
A sudden, brief burst of strong wind accompanied by rain or snow.
Can you ever dispatch a flight into icing?
Yes, but never Severe.
What conditions must exist to form ice?
Temperatures below 10C and visible moisture.
What are the three types of icing and their characteristics?
- Clear: Forms when supercooled droplets freeze on impact, hard to spot.
- Rime: Forms rapidly with supercooled droplets, opaque and disrupts airflow.
- Mixed: A combination of clear and rime ice.
What is CAT?
Clear Air Turbulence, occurring in cloudless skies, often at high altitudes.
What is a Hurricane?
A powerful tropical storm characterized by strong winds, heavy rain, and thunderstorms.
What is EWINS?
An Enhanced Weather Information System used for aviation weather data.
What is a SIGMET?
A weather advisory for significant weather phenomena affecting aviation safety.
What is an AIRMET?
A weather advisory alerting pilots to potentially hazardous conditions for small aircraft.
