12 Weather Theory Flashcards
How does air flow in terms of pressure?
High pressure to low pressure
How does wind flow in a high pressure system?
outward and clockwise
How does wind flow in a low pressure system?
inward and counterclockwise
What is the dew point?
The temperature at which air can hold no more moisture
What is radiation fog?
It occurs when the ground cool rapidly due to terrestrial radiation and surrounding air temperature reaches dew point (Ground fog if less than 20 ft thick)
What is advection fog?
warm, moist air moves over a cold surface (sea breeze blows air over cool landmass)
What is upslope fog?
Moist stable air forced up sloping land features
What is steam fog?
Cold air moving over warm water
What is ice fog?
When the temperature is below freezing and water vapor forms directly into ice crystals
What are the 4 types of low clouds? (Surface to 6500 ft)
Stratus, Stratocumulus, Nimbostratus, Fog (low ceilings, hamper visibility, change rapidly)
What are the 2 types of middle clouds? (6500 ft to 20,000 ft)
Altostratus and altocumulus (produce turbulence and moderate icing)
What are the 3 types of high clouds? (20,000 ft and up)
Cirrus, cirrostratus, cirrocumulus (no threat of turbulence or icing)
What kind of air causes bad air?
Warm, moist unstable air
What is a front?
Boundary layer between 2 types of air masses
What are the characteristics of a warm front?
They are slow, they replace cold fronts, they can bring fog, as they approach, the pressure lowers.
What are the characteristics of a Cold front?
They are fast, they replace warm fronts in a snow plow like way, high dew point, falling pressure, STORMS
What are the characteristics of a stationary front?
equal air masses, mix of cold and warm front?
What are the characteristics of a occluded front?
Fast cold meets slow warm.
cold front-fast cold air is colder than cold front ahead of the warm front forcing the warm air up. Mix of weather, stable air
warm front- air ahead is colder than the cold air coming. Cold air is forced above the warm air causing unstable air and severe weather.
What is a squall line?
A line of thunderstorms
