Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
67 Cards in this Set
- Front
- Back
|
What is a METAR?
|
Routine aviation weather report.
|
|
|
What is a TAF?
|
Terminal Area Forecast
|
|
|
What is an FA?
|
Area Forecast.
|
|
|
What is an FD?
|
Winds and temperatures aloft forecast.
|
|
|
What is a Significant Weather Prog Chart?
|
A prognosis chart forecasts:
1) Cloud cover 2) Turbulence 3) Freezing Level 4) Location of Fronts and high/low pressure systems. |
|
|
What is shown on a radar summary chart?
|
1)Location of precipitation radar echoes
coverage, movement, and tops. 2) Precipitation type and intensity are also identified. |
|
|
What is on a Surface Analysis Chart?
|
1)Fronts
2)Pressure systems 3)Isobars 4)Wind Direction and Velocity 5)Temperature and Dewpoint |
|
|
What is shown on a Weather Depiction Chart?
|
1)Areas of VFR
2)Marginal VFR 3)IFR 4)Visibility 5)Ceiling Height 6)Sky Coverage |
|
|
What is a Lifted Index?
|
Index of stability for a lifted parcel of air. (+) means stable (0) neutral
(-) means instability |
|
|
What is a Thermal Index?
|
Conveys atmospheric stability information. (+)=Stable (0)=Neutral
(-)=Instability |
|
|
How are PIREPS(pilot weather reports) filed?
|
By radio in flight to the nearest Flight Service Facility or by telephone after landing.
|
|
|
What useful info is there in PIREPS?
|
Observation of weather which would not be available to ground-based personnel.
|
|
|
What does UA mean in weather report coding?
|
UA means PIREP
|
|
|
What is a SIGMET
|
Advisories concerning significant weather to all aircraft. Tornadoes, lines of thunderstorms, embedded thunderstorms, large hail,severe and extreme turbulence, severe icing, and widespread dust or sandstorms reducing visibility to less than three miles.
|
|
|
What is an AIRMET
|
Describes areas which are hazardous to single engine and other light aircraft. Moderate icing, moderate turbulence, extensive IFR, strong surface winds and extensive mountain obscuration.
|
|
|
What's the diff between SIGMETs and AIRMETs?
|
SIGMET is for ALL...AIRMET are for small or limited equipment aircraft.
|
|
|
How are SIGMETS and AIRMETS disseminated?
|
By FSS - Flight Service Stations
|
|
|
What is a convective SIGMET?
|
Report of embedded thunderstorms.
|
|
|
What kind of NOTAMS are there?
|
L=Local
D=Distant FDC=Flight Data Center for NOTAMS available only FSS during preparation phase. |
|
|
What info is there in NOTAMS?
|
Broad array useful to pilots:
1)notices of airshows 2)runway closings 3)temporary state of non-operation due to normal maintenance and repair |
|
|
What are Wind Shear reports?
|
Warn pilots of hazardous wind shear which would affect airspeed during approach to landing. Significant shear may have substantial effect on glide angle, airspeed, and glide angle over the ground.
|
|
|
What is pressure lapse rate?
|
Reduction in barometric pressure that occurs with increasing altitude
|
|
|
What is the approximate pressure lapse rate in the lowest portion of the atmosphere?
|
Sea level to 14,000 feet MSL, about one inch of barometric pressure per thousand feet of ascent.
|
|
|
What is the barometric pressure at sea level for Standard Atmosphere?
|
29.92 inches of mercury..
|
|
|
What are temperature lapse rates?
|
Decrease in temperature with increasing altitude above sea level.
|
|
|
What is the temperature at sea level for Standard Atmosphere.
|
59 degrees F. 15 Centigrade
|
|
|
What is the temperature lapse rate in Standard Atmosphere.
|
3.5 Fahrenheit degrees per thousand feet of ascent in standard atmosphere.
|
|
|
What is the dry adiabatic lapse rate good for?
|
Tell us how much a rising parcel of air will cool as it ascends.
|
|
|
What is the dry adiabatic rate of cooling for a rising parcel of dry air?
|
5.4 Fahrenheit degrees per thousand feet of ascent.
|
|
|
Why is temperature-dewpoint convergence useful?
|
To predict height of cumulus clouds.
|
|
|
What is the rate of temperature-dewpoint convergence?
|
4.4 Fahrenheit degrees per thousand feet of ascent.
|
|
|
How do we calculate height of Cumulus clouds with temperature-dewpoint?
|
Temp difference * 1000 divided by 4.4
EX. 80-50=30 30x1000=30000 30000/4.4=6800 ft. |
|
|
When does Atmospheric Instability Occur?
|
If the measured temperature lapse rate exceeds 5.4 F degrees per thousand feet, a lifted parcel of air will continue to rise...cuz its warmer and less dense than the air above it
|
|
|
What hazards can accompany thunderstorms?
|
1)Turbulence
2)Powerful updrafts and downdrafts 3)Wind Shear 4)Obstructions to visibility 5)Heavy rain 6)Lighting 7)Hail 8)Downbursts 9)Strong Winds 10)Rapid change of wind direction with frontal passage |
|
|
What is Thermal Index?
|
Measure of atmospheric stability/instability. Subtract expected temperature from measured temperature. (+)=Stable (0)Neutral
(-) Instability |
|
|
What power triggers most thermals?
|
Solar heating of the earths surface
|
|
|
Why do thermal bubbles rise?
|
They are less dense than cooler surrounding air.
|
|
|
What are thermal streets?
|
Long lines of thermals usually arranged parallel to the wind. Can be present with or without cumulus clouds.
|
|
|
What does the cloud prefix ALTO mean?
|
High
|
|
|
What does Stratus mean?
|
Layered or stratified
|
|
|
What does cumulus mean?
|
Heaped Up
|
|
|
What does Cirro or Cirrus mean?
|
Clouds composed primarily of ice crystals rather than water droplets. Found high in the atmosphere.
|
|
|
What does "nimbo" or "nimbus" mean?
|
Rain
|
|
|
What does lenticular mean?
|
Lens-shaped, almond shaped
|
|
|
What does "rotor" mean?
|
Horizontally rotating air, often with a gap cloud on top. Found on lee side of mountain when wave present.
|
|
|
What cloud marks the beginning of a thunderstorm?
|
Cumulus cloud.
|
|
|
What is a squall line?
|
Pre-frontal line of cumulonimbus clouds
|
|
|
What weather phenomenon is associated with lenticular clouds?
|
Mountain wave(standing wave)
|
|
|
Can wave be present with no lenticular clouds visible?
|
YES...air is too dry for condensation.
|
|
|
When flying in wave and you notice the clear gaps between lenticular clouds decrease, what do you do?
|
Descend to a level beneath the clouds to keep contact with the horizon.
|
|
|
What clouds herald the approach of a warm front?
|
Stratus Clouds
|
|
|
What type of precipitation accompanies an approaching warm front?
|
Steady precipitation
|
|
|
What clouds accompany a cold front?
|
Cumulus clouds.
|
|
|
What type of precipitation accompanies a cold front passage?
|
Showery, episodic precipitation
|
|
|
What is a stationary front?
|
Slow moving boundary between two unlike air masses.
|
|
|
What is an occluded front?
|
An airmass of lighter, less dense air caught between two denser air masses.
|
|
|
What creates land and sea breezes?
|
Differential cooling and heating rates of land and water. Denser and cooler air offshore will flow landward causing displacement of warmer less dense air over the land.
|
|
|
What are valley and mountain breezes?
|
During daytime, heated air near a mountain slope flows up and out of the valley causing valley breeze. At night, the cooled air slides down the mountain into the valley causing mountain wind.
|
|
|
What is another name for ridge lift?
|
Orographic lift
|
|
|
What is necessary for ridge lift to occur?
|
Winds and a line of hills or ridges more or less at right angles to the wind direction
|
|
|
What hazzard is present on the downwind side of a ridge?
|
Heavy sink.
|
|
|
What is mountain wave?
|
Sinusoidal waves of lift and sink in the lee of a mountain or range.
|
|
|
What conditions form wave?
|
1)Stable air aloft
2)Winds of 20 knots or more 3)Wind more or less at right angles to the mountain range. |
|
|
What cloud type marks the presence of wave lift?
|
lenticular clouds
|
|
|
What is the atmospheric feature which sometimes underlies the wave close to the downwind side of the mountains?
|
The rotor
|
|
|
What is the principal hazzard of rotor?
|
Severe turbulence and strong winds.
|
|
|
What are the hazzards in the vicinity of thunderstorms?
|
1)Severe turbulence
2)Wind Shear 3)Squall lines 4)lightning 5)Low visibility 6)Downbursts 7)Heavy rain 8)hail 9)possibility of tornadoes |
