Weather Fundamentals Flashcards
Weather affects aviators in what three ways?
Reduce visibility
Create turbulence
Reduce AC performance
Natural air contains a variable amount of
Water vapor and
condensation nuclei
The most important element of weather usually not found above the troposphere is
Moisture
Six basic elements of weather
Temperature Pressure Wind Moisture Clouds Precipitation
What kind of cloud would you expect at low altitude in an UNSTABLE environment?
Cumuliform clouds
What kind of cloud would you expect at low altitude in a STABLE environment?
stratiform clouds
Avoid what kinds of clouds?
Cumulus / Cumulonimbus
What clouds should make you prepare for an alternate airport?
Stratus
WARNING CUNULONIMBUS MAY BE EMBEDDED IN STRATUS CLOUDS
CC cloud?
Cirrocumulus
Trouble at higher Altitudes: looks like popcorn
CS cloud?
Cirrostratus
Moisture is aloft, stable
CI cloud?
Cirrus
Wispy: strong winds at the cloud level, stable
Types of high clouds
Bases between 16,000 to 45,000 AGL
CIRRUS - CI
CIRROSTRATUS - CS
CIRROCUMULUS - CC
NS cloud?
Nimbostratus
AC cloud?
Altocumulus
About to make thunder storm, lifting forces with ripples and moisture, UNSTABLE, clouds are coming down
AS cloud?
Altostratus
Stable, a little moisture
Middle clouds?
Bases between 6,500 and 20,000 AGL
ALTOSTRATUS - AS
ALTOCUMULUS - AC
NIMBOSTRATUS - NS
CB with anvil cloud?
Cumulonimbus
Dissipating thunderstorm. Very strong winds up top, possible hail around immediate area from base of cloud anvil.
CB without anvil cloud?
Cumulonimbus
Fresh thunderstorm
SC cloud?
Stratocumulus
In between, there’s moisture. Possible transfer of weather
ST cloud?
Stratus
Stable conditions
CU cloud?
Cumulus
Generally unstable
Low clouds
Base writhing 6,500 AGL CUMULUS - CU STRATUS - ST STRATOCUMULUS - SC CUMULONIMBUS - CB
Describe cumulus clouds
Unstable, vertical clouds.
Describe stratus clouds
Flat, stable.
3 atmospheric conditions that provide the best lift
High pressure, low temp, low humidity.
Methods of heat transfer
CRAC
Convection: transfer of heat by gas in a vertical movement
Radiation: transfer of heat by electromagnetic waves
(Terrestrial: outgoing from earth )
(Insulation: incoming from the sun)
Advection: horizontal transfer of heat by wind
Conduction: transfer of heat by physical contact
Uneven heating of the earth is because of the 23.5* tilt of the earth and….
The Coriolis effect
The difference between convection and Advection
Convection: exchange of heat vertically
Advection: exchange of heat horizontally
Standard temp lapse rate is ___ per 1,000’
2*C
Temperature inversion
A layer of air increases in temp with altitude
Standard MSL in millibars
1013.2 hP/mb
Sky conditions with low pressure areas are produced by
Rising and cooling of the air.
What is an isobar?
A line connecting points of equal pressure corrected to MSL
The wind aloft or gradient wind circulation around a high pressure area is….
Going clockwise and parallel to the isobars
