Pressure and Atmosphere
Standard Pressure and Temperature at Sea Level
15ºC and 29.92 or 1013.2mb
Winds at 5,000 feet AGL on a particular flight are southwesterly while most of the surface winds are southerly. This difference in direction is primarily due to
friction between the wind and the surface.
What are the stages of a thunderstorm?
Three components for a thunderstorm to form
Cumulus, Mature, and Cumulus
Moisture, unstable atmosphere, and lifting force
Which are characteristics of an unstable cold air mass moving over a warm surface?
Cumuliform clouds, turbulence, and good visibility.
Which conditions are favorable for the formation of radiation fog?
Clear sky, little or no wind, small temperature/dew point spread, and over a land surface.
The primary cause of all changes in the Earth’s weather is
Variation of solar energy received by the Earth’s regions.
What causes surface winds to flow across the isobars at an angle rather than parallel to the isobars?
Surface Friction
True or False: A Sigmet is a significant weather report that contain, either thunderstorms that contain hail 3/4", moderate turbulence, dust storms, sandstorms, and even volcanic ash.
False
What are the characteristics of stable air?
Poor visibility, steady precipitation, and stratus-type clouds.
What types of fog depend upon a wind in order to exist?
Advection fog and up slope fog.
The average height of the troposphere in the middle latitudes is
37,000 ft
The strength and location of the jet stream in the summertime is normally
weaker and farther north.
Where do squall lines most often develop?
Ahead of a cold front.
What type clouds can be expected when an unstable air mass is forced to ascend a mountain slope?
Clouds with extensive vertical development.
In what localities is advection fog most likely to occur?
Coastal areas.
What layer of the atmosphere can thunderstorms extend to?
Stratosphere
Which weather phenomenon is always associated with the passage of a frontal system?
A wind change.
Drastic change in either window direction or speed
Wind Shear
The general characteristics of unstable air are
good visibility, showery precipitation, and cumuliform-type clouds.
The amount of water vapor which air can hold largely depends on
air temperature.
Which force, in the Northern Hemisphere, acts at a right angle to the wind and deflects it to the right until parallel to the isobar?
Coriolis Force
In which direction does the High/Low Pressure System flow?
High: Downward and clockwise
Low: Upward and counterclockwise
When water vapor evaporates before reaching the ground.
Virga
Unsaturated air flowing up slope will cool at the rate of approximately (dry adiabatic lapse rate)
3ºC
To which meteorological condition does the term “dew point” refer?
The temperature to which air must be cooled to become saturated.