Weather Flashcards
In general, what weather can you expect in a high pressure system?
A high pressure system is an area of descending air, which tends to favor dissipation of cloudiness and good weather.
What is the flow of air around high pressure systems in the northern hemisphere?
Outward, downward, clockwise.
What are the general characteristics of the weather near a cold front?
As the front passes expect towering cumulus or cumulonimbus clouds, heavy rain, lightning, thunder and hail, poor visibility. Winds could be variable and gusting. Temp/dew point/pressure drop rapidly.
What are the different precipitation types?
Drizzle, rain, freezing rain, freezing drizzle, snow, snow grains, ice crystals, ice pellets, hail, small hail, snow pellets
What are the 3 primary causes of turbulence?
Convective currents
Obstructions in the wind
Wind sheer
What is the flow of air around a low pressure system in the northern hemisphere?
Inward, upward, counterclockwise
What are the general characteristics of the weather near a warm front?
As the front passes, expect weather, stratiform clouds, drizzle, low ceilings poor visibility, variable winds and a rise in temp.
4 levels of turbulence
Light
Moderate
Severe
Extreme
What is a Convective SIGMET?
Thunderstorms
Squall Lines
Hail
What are the three types of AIRMETs?
Sierra- visibility
Tango- turbulence
Zulu- icing
High level clouds above 20,000 ft, fibrous, wispy.
Cirrus
Rime Ice
Opaque appearance
formed in stratus clouds
results from instantaneous freezing of tiny super cooled water striking an aircraft surface
-15 C to -20 C
Which thunderstorms produce the most intense hazards to aircraft?
Squall line thunderstorms
Lower Clouds 6,500 ft and below
Stratus
Ice Fog
In cold weather when the temp is much below freezing and water forms directly into ice crystals.
What would decrease the stability of an air mass?
Warming from below
When the term light and variable is used in reference to winds aloft the coded group and wind speed is…
9900 and less than 5 knots
A pilot can expect a wind-sheer zone in a temperature inversion whenever the wind speed at 2,000 - 4,000 AGL is at least…
25 knots
What is standard pressure
29.92 in
What is standard temperature in Celsius?
15 C
The wind condition that requires maximum caution when avoiding wake turbulence on landing is
light quartly tailwind.
What is Inversion
Shallow layers of smooth stable air close to the ground . Warm area above keeping air trapped.
What is atmospheric stability
The stability of atmosphere is the ability to resist vertical motion
Cold Front
Dense mass of air, stays close to the surface. Advances quickly.