Weather Information Flashcards
What weather is associated with a cold front?
Gusty Winds Hail Dropping Temps Thunder Lightening (Tornados)
What happens when warm air gets lifted ahead of a front?
Cumulous or cumulonimbus clouds & thunderstorms
What is a SIGMET and what conditions are included?
Indicates Significant weather such as: Severe icing (w or w/o thunderstorms) Severe turbulence (w or w/o thunderstorms) Dust/Sand storms Volcanic ash Valid 4 hours (6 for hurricanes)
What is an AIRMET and what conditions are included??
An AIRMET is a concise description of weather phenomena that are occurring or may occur (forecast) along an air route that may affect aircraft safety. Considered less severe than SIGMETS.
Sierra = IFR & Mtn obscuration
Tango = Turbulence, strong surface winds, low level wind shear
Zulu = Icing & Freezing
What is a Convective SIGMET?
Thunderstorm related - valid for 2 hours
What is the dew point?
Temp at which an airmass can hold no more moisture.
Moisture becomes visible when temp to dew point spread is within 2 degrees c (3.5 f)
What should you do if you have and inadvertent encounter with IMC?
Make a 180 - radio for assistance
Keep wings level and stay calm
Spatial disorientation is likely - trust the instruments not your own sensations
How far should you remain from thunderstorms?
20 miles
What is Density Altitude?
Is Pressure Altitude corrected for nonstandard temp.
As density of air increases (lower density alt), aircraft performance increases and vice versa.
What is Pressure Altitude?
Height above standard datum plane which is a theoretical level where the weight of the atmosphere is 29.92 “Hg.
What is a Temperature Inversion?
Typically air cools as it rises and expands. Inversion happens when the temperature rises with altitude. Typically creates shallow layers of smooth, stable air near the ground. Air at top acts like a lid trapping weather and pollutants trapped below. If high humidity it can contribute to the formation of clouds, fog, haze or smoke.
How does Humidity effect Density?
Water vapor is lighter than air.
Higher humidity = air becomes less dense and density altitude increases
TAFs cover what area?
Specific to an airport - 5 sm RADIUS around it.
What are the 3 stages of a thunderstorm?
Cumulus stage, mature stage & dissipating stage.
What are the 3 conditions necessary to create a thunderstorm?
Unstable air, high moisture content and a source of lift.