Private Pilot Weather Assessment Questions and Answers 100% Pass

Private Pilot Weather Assessment Questions and Answers 100% Pass Define LIFR - Answers Low IFR - Ceiling less than 500ft and/or visibility less than 1 mile Define IFR - Answers Ceiling 500ft to less than 1,000ft and/or visibility 1 to less than 3 miles Define MVFR - Answers Marginal VFR - Ceiling 1,000ft to 3,000ft and/or visibility 3 to 5 miles Define VFR - Answers Ceiling greater than 3,000ft and visibility greater than 5 miles; includes sky clear Define cloud ceiling - Answers Lowest Broken or Overcast What is the flow of low pressure in the Northern Hemisphere? - Answers Inward, upward, and counterclockwise What is the flow of high pressure in the Northern Hemisphere? - Answers Outward, downward, and clockwise Define a trough - Answers An elongated area of relatively low atmospheric pressure. An area of rising air. Conductive to cloudiness and precipitation; bad weather Define a ridge - Answers An elongated area of relatively high atmospheric pressure. An area of descending air. Favors dissipation of cloudiness; good weather What is the standard temperature and pressure values for sea level? - Answers 15 degrees Celsius, 29.92" Hg What are isobars - Answers A line on a weather chart which connects areas of equal or constant barometric pressure What does the spacing of the isobars depict - Answers Shows how steep or shallow a pressure gradient is. Closer together the gradient is steeper, higher wind speeds; Shallow pressure gradient, lower wind speeds What causes wind to flow parallel to the isobars? - Answers Coriolis Force Why do surface winds generally flow across the isobars at an angle? - Answers Surface Friction How much atmospheric pressure (Hg) decrease with an increase of altitude? - Answers 1Hg per 1,000ft Define Dew point - Answers The Temperature to which a sample of air must be cooled to attain the state of saturation When temperature and dew point are close together (with 5 degrees) what type of weather is likely? - Answers Visible moisture in the form of clouds, dew, or fog; ideal for carburetor icing What factor primarily determines the type and vertical extent of clouds? - Answers The stability of the atmosphere How do you determine the stability of the atmosphere? - Answers Unstable air is indicated when temperature decreases uniformly and rapidly as you climb. If temperature remains unchanged or decreases only slightly with altitude the air tends to be stable. Instability is likely when air near the surface is warm and moist. Surface heating, cooling aloft, converging or upslope winds, or an invading mass of cold air may lead to instability and cumuliform clouds. What effect does stable air have on clouds? - Answers Stratiform What effect does unstable air have on clouds? - Answers Cumuliform What effect does stable air have on Turbulence? - Answers Smooth What effect does unstable air have on Turbulence? - Answers Rough What effect does stable air have on Precipitation? - Answers Steady What effect does unstable air have on Precipitation? - Answers Showery What effect does stable air have on Visibility? - Answers Fair to poor What effect does unstable air have on Visibility? - Answers Good Define Freezing Level - Answers Lowest level in the atmosphere over a given location at which the air temperature reaches 0 Celsius How can you determine where freezing level is? - Answers Its Forecasted; Area Forecasts, AIRMETSs, SIGMETs, and low level significant weather charts, also review PIREPs What conditions do you need for structural icing? - Answers Visible moisture and below freezing temperatures What are them main types of icing on an aircraft? - Answers Structural, induction system, and instrument icing What are the three types of structural icing? - Answers Clear, Rime, Mixed What actions should you do if you inadvertently encounter icing conditions? - Answers Change Course and/or Altitude; Climb higher Is frost hazardous to flight? - Answers Yes, because the roughness of its surface spoils the smooth flow of air. What factors do you need for a thunderstorm? - Answers A. A Source of Lift B. Unstable Air