JX101

• Height: 28,000-55,000 in height
• Large amounts of moisture and condensation
• Nearlly all weather occurs here
• Temperature normally decreases with altitude

• Transition between troposphere and stratosphere
• Height over US 36,000ft
• Strongest winds occur just below the tropopause
• Temperature is constant with altitude
• Normally the coldest area in lower atmosphere
• Haze layer with definite top
• Contrails form here

• Height up to 66,000 ft
• Increasing temperature as altitude increases
• Smooth with excellent visibility

The decrease in temperature with increasing altitude

2° per 1000'

Indicates the temperature is constant with increasing altitude

• Temperature inversion
• occurs in stratosphere when temperature increases with increasing altitude

14.7lbs

• True
• Pressure decreases more rapidly in the lower levels of atmosphere, than at higher altitudes, because density decreases with altitude

• 29.92 inHg; 1013.2mb
• 15°C or 59°F
• Lapse rate 1 inHg per 1000'
• Temperature lapse rate 2°C (3.5°F) per 1000'

Atmospheric pressure measured directly at an airfield or other weather station

• depict high and low pressure systems as they move across the country bringing differing weather patterns
• Lines of equal pressure are called isobars

Aneroid barometer calibrated to display altitude in feet

Its the value to which the scale of the pressure altimeter is set to so the altimeter indicates true altitude at field elevation

4%

• lower
• Hotter = higher

In the same direction in the areas between pressure systems and parallel to the isobars

The rate of change in a direction perpendicular to the isobars

• isobar spacing
• The initiating force for all winds
• Tighter spacing of isobars shows a steep pressure gradient - strong winds

• Descending air
• Clockwise

• Ascending air
• Counterclockwise

• Gradient winds which flow perpendicular to the pressure gradient force
• Parallel to isobars
• Generally above 2000' AGL

• Friction reduces the speed of the wind which causes a reduction in Coriolis force
• Air blows at angles (45°) across the isobars

• Maximum in the tropopause
• Narrow band of strong winds, +50 knots
• Average height 30,000 MSL
• 100-150+ knots
• 1000-3000 miles long
• 100-400 miles wide
• 3000-7000' deep

Winds created by mountains, valleys, and bodies of water, and are superimposed on general wind systems possibly causing significant changes in the weather

• During the day, lower pressure over the land and that over water is higher, causing the cool air to move to lower pressure over the land
• 

• Cold land, high pressure; warm water, low pressure. Air flows from high to low
• 

• Warm air near the ground being pushed up the mountain
• Air is flowing out of the valley

Dense air flows downhill into the valley

more

Air contains the maximum amount of water vapor for a given temperature

• The temperature at which saturation occurs and is a direct indication of the amount of moisture in the air
• Higher the dew point, greater chance for clouds, fog or precipitation

percent of saturation of the air or, percentage of water vapor in the air compared to the maximum amount the air could hold at that temperature

• Showers: starts, stops, changes intensity or sky conditions, cumuliform clouds
• Continuous: steady and changes intensity gradually, stratiform clouds
• Intermittent: Stops and starts at least once during the hour, cumuliform or stratiform clouds

• Drizzle
• Rain
• Frozen

• Bases: 6500 AGL
• Turbulence: none - moderate
• Precipitation: light rain - drizzle
• Can produce icing

• Bases: 6500 - 20,000'
• Prefix: alto
• Composed of ice crystals, water droplets
• Visibility: 1/2 mile to few feet
• Icing

• Bases: +20,000 AGL
• Prefix: cirro or contain the word cirrus
• Composed of ice crystals
• Moderate turbulence
• No icing

• Towering cumulus and cumulonimbus
• Nearing thunderstorm stage and produce heavy rain and moderate turbulence
• Icing common above freezing level

• Bases: 1000' AGL
• Continuous rain snow, or ice pellets
• Poor visibility and low ceilings

• Thunderstorm clouds
• Extremely hazardous

• Stable condition
• When the lifting action is removed, the lifted air settles because it is denser

• Unstable condition
• When lifting is removed it continues to rise because it is less dense

• Neutrally stable condition
• Lifted air will remain at the point where lifting was removed

• when two air masses or parts of a single air mass converge and force air upward because it has nowhere else to go
• 

• Cold fronts moving through an area and lifting the air ahead of them
• 

The force of wind against a mountainside pushes air upward

• Convective lifting:
• Cool air is over a warm surface and is heightened by intense solar heating

• Clouds: Stratus
• Turbulence: Smooth
• Visibility: Poor
• Winds: Steady
• Precip: Steady
• Icing: Rime
• Temperature inversions, low clouds or fog, rising temperatures while climbing

• Clouds: Cumulus
• Turbulence: Rough
• Visibility: Good
• Winds: Gusty
• Precip: Showery
• Icing: Clear
• Thunderstorms, towering cumulous clouds, heavy showers, dust devils, decreasing temperature while climbing