Weather Flashcards
High pressure air
Dry descending air down word and outward that moves clockwise
Low pressure air
Move upwards and then words counterclockwise typically brings poor weather
Troposphere
is where most weather occurs
Standards of weather
- 92 inches of mercury
1013. 2 millibars
Mechanical turbulence
Caused by air moving around
Buildings
Windshear
Low level windshear
Sudden change in wind speed and direction
Caused by changing fronts
thunderstorms
Temperature inversion
Microburst
Severe lower level windshear
Last for 5 to 15 minutes and 5000 ft./min. winds
Radiation fog
CAlM nights no wind
Ground is cold air is warm
Dissipates quickly
Advection fog
Warm moist air moves on cold surface
Needs wind for fuel and last many days
Upslope fog
Warm moist air up mountain
Requires wind for fuel last many days
Steam fog
Warm moist air evaporates to cool dry air
Coffee fog
Stable air mass
Stratus clouds poor visibility steady precipitation
Unstable air mass
Cumulus clouds good visibility shower and precipitation
Cold front
Cold air replaces warm air
Moves faster than warm air and is steeper
Brings storms and gusty wins
Warm front
Slow and warm slide up and over cold air
Low ceiling and poor visibility
Stationary fronts
Slowly dying Front
last a couple days
mix of warm and cold front
Occluded front
Warm and cold front moving together
Points of intersection is worst area for weather
Thunderstorms
Avoided by 20 miles minimum
Requires lifting action
moisture in air and unstable lapse rate
Cumulus stage
Updrafts of wind
Mature stage
Rain touches the ground most violentStage
Dissipating stage
Microbursts and rain
Rime ice
Forms on leading edge as water freezes on impact
Clear ice
Most dangerous and disturbs airflow
Moves back and freezes on upper surface
Mixed ice
Combination of Rime ice and clear ice
