Meterolgoy Flashcards
Most common cause of cloud formation
Adiabatic expansion
Stable air clouds
Stratus
Unstable air clouds
Cumulus clouds
Windward and leeward side of a hill/mountian
Windward is the side the wind is blowing on
Leeward is the side sheltered from the wind
Orographic
Air blowing against a hill/mountain and being forced up it. (Can create chinooks on other side of the hill/mountain)
Convection
Warm air rising due to heating of the ground by the sun. (Upward movement is convection and downward of air movement is subsidence)
Frontal Lift
Warm air pushed up and raising over cold air on a long gradual slope
Divisions of the atmosphere
Troposphere, stratosphere, mesosphere, thermosphere, exosphere
Types of pressure areas
Low, high, trough of low, secondary low, col, ridge of high
Azimuth
Used to describe the direction of an aircraft in relation to true north
Types of turbulence
Mechanical, thermal, frontal, wind shear, clear air turbulence (CAT)
Factors to consider for critical surface contamination
Ambient temp, a/c surface temp (including cold soaking), precipitation type and rate, relative humidity, wind direction and velocity, operation in proximity to other a/c, operation on snowy/slushy/wet surfaces, a/c configuration and surface roughness
Coriolis Effect/Force
Caused moving air to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere
Low Pressure Systems
Counterclockwise in northern hemisphere
Know as troughs especially when elongated shape
Rising air and arrival of cloudy WX and precipitation
High Pressure System
Clockwise in northern hemisphere
If elongated shape, referred to as a ridge of high pressure
Descending air(subsiding) usually clear wx and gentle wind
Cloud coverage
Clear-sky clear below 10,000
SKC-no clouds
Few-clouds greater than 0 up to 2/8
Scattered- between 3/8-4/8
Broken-5/8 up to less than 8/8
Overcast-8/8
BR/FG
Mist visibility 5/8 or greater
Fog less than 5/8 visibility
Ceiling definition
Height of the base of cloud of the lowest broken or overcast layer
Cloud base calculation
Adiabatic lapse rate
Standard 2(1.98)/1000
Dry 3/1000
Saturated 1.5/1000
Dew point 0.5/1000
Cloud base=(temp-dew)/(dry lapse-dew lapse which 3-0.5 so is 2.5)
Anabatic/Katabatic
Anabatic (day) wants slopes and creates wind going up the slope
Katabatic (night) slope cools faster and creates wind going down the slope
Mountain Waves
Lenticular clouds (also called ACSL, altocumulus standing lenticular)
Cap cloud
Rotor cloud
Clouds may not be present in a mountain wave
Fog Types
Radiation Fog-land cool at night, less 5kt wind, cools air and fog results
Advection Fog-land is already cool, warm air blown, air cools and fog. Up to 15kts winds
Frontal Fog-fronts, warm above cooled and rains, rain evaporates in the cool air and makes it cooler and then fog can result when dew point reached
Arctic Sea Smoke-cold air over warm water, saturates air and fog occurs
Upslope Fog-air forced upslope and cools adiabatically and fog occurs
Air Masses
cA -continental arctic-dry/cold/stable/low alt
mA-maritime arctic-moist/cold/unstable in lower layers, low alt
mP-maritime polar-moist/unstable throughout,higher level
mT-maritime tropical-moist/hot/very unstable, high alt
Microburst/Macroburst
Microburst-less than 2NM horizontal and less than 5min
Macroburst-greater than 2NM horizontal and lasts between 5-20min
