Weather

a heat exchange

evaporation and sublimation

right by Coriolis force

Coriolis force tends to counterbalance the horizontal pressure gradient

close together, the pressure gradient force is greater and wind velocities are stronger

Pressure differences

is warmer than the air behind the overtaking cold front

A high-pressure area or ridge is an area of descending air

A low-pressure area or trough is an area of rising air

left and increasing

are flying toward an area of generally unfavorable weather conditions

Coriolis force

outward, downward, and clockwise

a cyclone and is caused by Coriolis force

south and speed increases

weaker and farther north in the summer

in an upper trough on the polar side of a jet stream

long streaks of cirrus clouds

on the low-pressure side of a jetstream core where the speed at the core is stronger than 110 knots

A curving jetstream associated with a deep low-pressure trough

Abrupt change in temperature lapse rate

-5°C

15 °C and 29.92" Hg

-25 °C

decreases as the relative humidity increases

Towering cumulus clouds

Unstable, moist air and orographic lifting

Cumuliform clouds, turbulence, and good visibility

6,000 feet MSL

The stability of the air before lifting occurs

very strong turbulence

streamers of precipitation trailing beneath clouds which evaporates before reaching the ground

evaporation of precipitation

Precipitation-induced fog

an air mass moving inland from the coastline during the winter

Wind 15 knots or stronger

Radiation fog is restricted to land areas; advection fog is most common along coastal areas; steam fog forms over a water surface

Surface winds of approximately 15 knots or stronger

Clear, cool nights with calm or light wind

It can appear suddenly during day or night, and it is more persistent than radiation fog

Poor visibility; steady precipitation; stratus clouds

Warming from below

Cooling from below

Stratiform clouds

Restricted visibility

Continuous precipitation

Strong updrafts and cumulonimbus clouds

cumuliform clouds and showery precipitation

stratus type with little vertical development and little or no turbulence

stability of the air being lifted

Smoke, dust, haze, etc., concentrated at the lower levels with resulting poor visibility

Cool air must sink to force the warm air upward

Strong updrafts and cumulonimbus clouds

land absorbing and radiating heat faster than the water

The ambient lapse rate

lifted index

stable, moist air

Cumulonimbus clouds, very frequent lightning, and roll clouds

Continuous updraft

unstable, moist air

squall lines

Outside the cloud, shear turbulence can be encountered 20 miles laterally from a severe storm

They offer the most intense weather hazards to aircraft

They are nonfrontal and often contain severe, steady-state thunderstorms

The beginning of rain at the Earth's surface indicates the mature stage of the thunderstorm

The radarscope provides no assurance of avoiding instrument weather conditions

The start of rain

Dissipating

40 miles

20 miles

more than 32°F into air having a temperature of 32°F or less

Hailstones may be encountered in clear air several miles from a thunderstorm

cumulonimbus clouds

a warm front is about to pass

freezing rain exists at higher altitude

Freezing rain at higher altitude

light turbulence

moderate

clear air turbulence

6 knots per 1,000 feet

below rotor clouds

stable air at mountaintop altitude and a wind of at least 20 knots blowing across the ridge

leeward side when flying into the wind

light

a loss in airspeed equal to the decrease in wind velocity

power and vertical velocity required to remain on the proper glidepath

It can be present at any level and can exist in both a horizontal and vertical direction

there is a low-level temperature inversion with strong winds above the inversion

in areas of temperature inversion and near thunderstorms

wind shear