Weather Flashcards
What type of weather is commonly associated with low-pressure areas?
Increasing cloudiness and precipitation.
How does air flow in relation to a low-pressure area?
Air flows into a low-pressure area to replace rising air.
What is a trough in relation to weather systems?
An elongated area of relatively low atmospheric pressure.
What is the standard atmospheric pressure lapse rate?
Pressure decreases by approximately 1 “Hg per 1,000 feet of altitude gain up to 10,000 feet.
What should pilots consider during approach and landing with ice on the airframe?
Carefully deploy flaps/slats in stages, monitor aircraft behavior, and increase approach airspeed by at least 25%.
Where can pilots find information regarding freezing levels?
AIRMET ZULU, GFA, Significant Weather Prognostic Chart, Winds and Temperatures Aloft Forecast, Freezing Level Forecast Graphic.
How does frost affect an airfoil’s performance?
Frost can reduce lift by 30% and increase drag by up to 40%.
What are the characteristics of clear ice?
Glossy, clear ice formed by slow freezing of supercooled water drops.
What are the characteristics of rime ice?
Rough, milky, opaque ice formed by rapid freezing of supercooled drops.
What are the characteristics of mixed ice?
A combination of clear and rime ice, often with a cloudy appearance.
What is roll upset and why may it occur in icing conditions?
Roll upset is uncommanded roll due to severe icing causing airflow separation and loss of roll control.
Why can’t you fly with frost on the airplane in the morning?
Frost reduces lift and increases drag, affecting takeoff performance.
What conditions are associated with a passing cold front?
Towering cumulus clouds, heavy rain, poor visibility, gusty winds, temperature and pressure drop.
How does structural icing occur on an aircraft?
Structural icing occurs when supercooled water droplets strike the airframe and freeze.
What three conditions are required for thunderstorms to develop?
Water vapor, unstable air, and a lifting source.
What are PIREPs and what information do they contain?
PIREPs are pilot reports of en route weather, including location, time, flight level, aircraft type, and one weather element.
What is the primary danger of flying under the anvil of a thunderstorm?
Potential for severe clear air turbulence.
How far should you stay from thunderstorms to avoid turbulence?
Up to 20 miles from severe thunderstorms; 10 miles from less severe storms.
What is tailplane icing and what precautions should be taken?
Ice on the tailplane can cause a nose-down pitch; consider a no-flap landing.
What are good methods for removing frost from an airplane?
Placing the aircraft in a heated hangar or using freezing-point depressant fluids.
What are the aerodynamic hazards of structural icing?
Ice reduces lift, alters airfoil shape, blocks control surfaces, and can cause roll upset.
What are the first areas to check for ice accumulation on an aircraft?
Small or narrow objects like probes or the tailplane accumulate ice first.
When does frost typically form on an aircraft?
Frost forms on clear nights when the aircraft’s skin temperature drops below freezing.
How should datalink weather products (FIS-B) be used when flying in active weather?
For strategic weather decision-making, not for tactical weather avoidance.
What criteria make a PIREP urgent (UUA)?
Tornadoes, severe turbulence, severe icing, hail, LLWS, volcanic ash, or hazardous weather phenomena.
What are the four levels of icing severity in a PIREP?
Trace, Light, Moderate, Severe.
What actions should you take if you inadvertently fly into a thunderstorm?
Tighten seatbelts, adjust altitude, activate pitot heat, set turbulence penetration speed, and monitor airborne radar.
What are SIGMETs and why are they issued?
SIGMETs are issued for severe turbulence, severe icing, widespread dust/sandstorms, and volcanic ash.
What are convective SIGMETs and why are they issued?
Convective SIGMETs are issued for thunderstorms, tornadoes, large hail, and wind gusts ≥ 50 knots.
What defines VFR, MVFR, IFR, and LIFR conditions?
VFR: Ceiling >3,000 ft, visibility >5 miles. MVFR: 1,000-3,000 ft, visibility 3-5 miles. IFR: 500-1,000 ft, visibility 1-3 miles. LIFR: <500 ft, visibility <1 mile.
What are the three stages of a thunderstorm?
Cumulus, Mature, Dissipating.
What weather conditions are associated with an occluded front?
Embedded thunderstorms, rain, and fog as cold front overtakes a warm front.
What does it mean when an airmass is stable?
A stable airmass resists upward displacement.
What information is available from a Surface Analysis Chart?
It shows pressure systems, fronts, winds, temperatures, and dew points.
What are the three types of AIRMETs and why are they issued?
AIRMET Sierra: IFR/mountain obscurations; AIRMET Tango: turbulence/strong winds; AIRMET Zulu: moderate icing/freezing levels.
What can be learned from the distance between isobars on a constant pressure chart?
Closely spaced isobars indicate strong winds; widely spaced isobars indicate lighter winds.
How should you submit a PIREP in flight?
Submit PIREPs to the nearest ground facility such as FSS, ARTCC, or terminal ATC.
How can a pilot prepare to avoid icing conditions?
Review freezing levels, PIREPs, AIRMETs, SIGMETs, and monitor OAT frequently during flight.
Which weather reports provide cloud layers in AGL and which in MSL?
METARs and TAFs report in AGL; PIREPs and GFA report in MSL.
What weather is associated with high-pressure systems?
High-pressure systems bring dry, descending air and generally favorable weather.
What kind of weather can you expect with a low temperature-dewpoint spread?
Visible moisture, such as clouds, fog, or dew.
What is a microburst and what would a pilot experience flying through one?
A microburst is an intense downdraft causing wind shear. A pilot would first experience increased performance, then a downdraft, followed by a strong tailwind.
What actions should you take if you inadvertently fly into icing conditions?
Exit visible moisture by descending, climbing, or changing course, and report icing to ATC.
Under what meteorological conditions is airframe icing most likely to occur?
Icing is most likely in visible precipitation with temperatures between +2°C and -10°C.
What is the dew point and why is it important to pilots?
Dew point is the temperature at which air becomes fully saturated, leading to fog, clouds, or precipitation.
What is a ridge in relation to weather systems?
An elongated area of relatively high atmospheric pressure.
What are the methods for obtaining a preflight weather briefing?
Flight Service, mobile apps, or the Aviation Weather Center website.
What conditions are associated with a stationary front?
A mixture of warm and cold front weather that can persist for days.
What conditions are associated with a warm front?
Stratiform clouds, drizzle, poor visibility, rising temperatures, and variable winds.
What are the three types of weather briefings?
Standard, Abbreviated, and Outlook briefings.
What is wind shear and where is it most likely encountered?
A sudden change in windspeed/direction, most dangerous at low altitudes and near thunderstorms or frontal systems.
How does airflow behave around high and low pressure systems in the Northern Hemisphere?
High pressure: clockwise and outward; Low pressure: counterclockwise and inward.
What are the differences between a stable and an unstable atmosphere?
Stable atmosphere resists vertical motion; unstable atmosphere encourages vertical air movements and turbulence.
What is the phone number for Flight Service (FSS)?
1–800–992–7433 (1-800-WX-BRIEF).
How should a pilot report a wind shear encounter?
Report the airspeed loss or gain and the altitudes at which it was encountered to ATC.
