Weather

Question 0

Rotation of a high pressure system

Answer 0

Outward and clockwise (anti cyclonic)
Generally dry, stable, descending air.
Typically associated with good weather.

Question 1

Coriolis force

Answer 1

Force created by the rotation of the earth which effects circulation patterns causing them to follow a curved path.

Question 2

Low pressure

Answer 2

Inward, upward and counter clockwise (cyclonic)

Generally associated with bad weather.

Question 3

Low level wind shear

Answer 3

Sudden and dramatic change in wind speed and/or direction over a small area. Extremely hazardous to aircraft. Directional changes of 180 degrees and wind speeds of 50 knots or more.

Question 4

Types of fog

Answer 4

Radiation fog
Advection fog
Upslope fog
Precipitation induced fog
Ice fog

Question 5

What are the three stages of a thunderstorm?

Answer 5

Cumulus stage: up drafts cause raindrops to increase in size.
Mature stage: rain at earth’s surface which falls through or immediately beside the updrafts, lightning and roll clouds.
Dissipating stage: down drafts and rain begin to dissipate.

Question 6

Two basic ways fog can form

Answer 6

Cooling air to the dew point

Adding moisture to the air close to the ground

Question 7

What is a temperature inversion?

Answer 7

An increase in temperature with height. A ground based inversion favors poor visibility. The air is stable with little or no turbulence.

Question 8

What conditions are necessary for structural icing to occur?

Answer 8

Visible moisture and below freezing temperatures at the point moisture strikes the aircraft.

Question 9

Types of icing that an aircraft may encounter in flight

Answer 9

Structural, induction system and instrument icing.

Question 10

Recommended action for inadvertent encounter with icing conditions

Answer 10

Leave the area of visible moisture. Descend below the cloud base, climb above the cloud tops or turn to a different heading.

Question 11

Factors necessary for the formation of a thunderstorm

Answer 11

Sufficient water vapor
An unstable lapse rate
An initial upward boost to start the storm process in motion

Question 12

Rate of decrease in atmospheric pressure with increase in altitude

Answer 12

1” Hg per 1,000 feet above sea level

Question 13

What are the effects of stable and unstable air on clouds, turbulence, precipitation and visibility?

Answer 13

Stable.  -   unstable
Clouds:          Stratiform - cumuliform
Turbulence:    smooth - rough
Precipitation: steady - showery
Visibility:        fair to poor - good

Question 14

What information should a weather briefing include?

Answer 14

Adverse conditions 
VFR flight not recommended 
Synopsis 
Current conditions 
Enroute forecast 
Destination forecast 
Winds aloft 
Notices to airmen

Question 15

Define: EFAS

Answer 15

En route flight advisory is a service which provides en route aircraft with timely and meaningful weather advisories pertinent to the flight. On frequency 122.0 MHz. “Flight Watch”

Question 16

Define: HIWAS

Answer 16

Hazardous in-flight weather advisory service is a continuous broadcast of in-flight weather advisories including summarized aviation weather warnings, SIGMETS, convective SIGMETS, AIRMETS, and urgent PIREPS.

Question 17

Define: METAR

Answer 17

Hourly surface observations of weather conditions at an airport. A routine METAR is transmitted every hour while a SPECI can be given at any time to update the METAR for rapidly changing weather conditions, aircraft mishaps or other critical information.

Question 18

Define: AWOS

Answer 18

Automated weather observation system; consists of sensors, a processor, a computer generated voice system and a transmitter to broadcast local minute by minute weather data to pilots.

Question 19

Define: ASOS/AWSS

Answer 19

Automated weather observing system/automated weather sensor system; the primary U.S. Weather observing systems. Provide continuous minute by minute observations that generate METARs and other aviation weather information. Transmitted over a discrete VHF radio frequency or the voice portion of a local NAVAID.

Question 20

Define: TAF

Answer 20

Terminal aerodrome forecast is a concise statement of the expected meteorological conditions significant to aviation for a specified time period within five statute miles of the center of the airport’s runway complex (terminal). Same codes as METAR

Question 21

Define: FA

Answer 21

Aviation area forecast specifies weather phenomena covering a flight information region or other area designated by the meteorological authority. Issued three times daily for each of the six areas in the contiguous 48 states. Information provided:
Synopsis, clouds and weather, 12 to 18 hour outlook: IFR, MVFR, or VFR including precipitation and/or Obstructions to visibility.

Question 22

LIFR
IFR
MVFR
VFR

Answer 22

LIFR: ceilings < 500' AGL  
         visibility < 1nm
IFR: ceilings 500'-1,000' AGL  
        visibility 1-3nm
MVFR: ceilings 1,000'-3,000' AGL
            visibility 3-5nm
VFR: ceilings > 3,000'   
         visibility > 5nm

Question 23

SIGMET

Answer 23

Severe icing and/or turbulence not associated with a thunderstorm, dust or sandstorm lowering visibility less than 3nm, volcanic ash

Question 24

Convective SIGMET

Answer 24

Severe thunderstorm with surface winds greater than 50 knots hail larger than 3/4” tornadoes, embedded thunderstorms, a line of thunderstorms or thunderstorms covering more than 40% of an area 3,000 square miles.