METEOROLOGY STCW EXAM
QUESTIONS AND ANSWERS 100%
CORRECT
Air pressure - ANSWER-The mass of air above a given level
How does atmospheric pressure change with height? - ANSWER-Atmospheric pressure
always decreases with increasing height
What is wind and what causes it? - ANSWER-It is the movement of air, it is caused by
the uneven heating of the earth's surface
What is constant in a sea-level pressure chart? - ANSWER-Constant height
What is constant in an upper level or isobaric chart? - ANSWER-Constant pressure
surface (500 mb), high heights correspond to higher than normal pressures at given
latitudes and vice versa
What do isobars on a constant height chart look like? - ANSWER-The isobars represent
variations in horizontal pressure at that altitude. An average isobar at sea level would be
about 1000mb, at 3000m (10,000ft) about 700 mb, and at 5600m (18,400ft) about 500
mb
What is an isobaric surface? - ANSWER-Surface of constant pressure
What happens to the isobaric surface because of the changes of air density? -
ANSWER-Because of the changes of air density, the isobaric surface rises in warm,
less dense-air and lowers in cold, more dense air.
How high is the tropopause? What is its pressure? What weather system will you find
there? - ANSWER-36,000 ft. 250 mb, and you will find the jet stream
How high are winds aloft? What is the pressure at that altitude? - ANSWER-18,000 ft
and 500 mb
How high is the boundary layer? What is the pressure at that altitude? What weather will
you find there? - ANSWER-2,000-3,000ft, 920 mb. You find clouds there
How high is the surface layer? What is the pressure at that altitude? - ANSWER-30-100
ft and 1000 mb
, What is geostrophic wind? - ANSWER-Above the level of friction, air initially at rest will
accelerate until it flows parallel to the isobars at a steady speed with the pressure
gradient force (PGF) balanced by the Coriolis effect
What direction is cyclonic flow? - ANSWER-Counter-clockwise
What direction is anticyclonic flow? - ANSWER-Clockwise
Wind aloft flow what direction between isobars? - ANSWER-Parallel to isobars
Winds at the surface flow what direction? - ANSWER-Flow at 30 degree angels to the
isobars
In a high pressure system at the surface, what direction do the winds flow? - ANSWER-
The winds face outwards, in clockwise motion at 30 degree angles to the isobars
In a low pressure system at the surface, what direction do the winds flow? - ANSWER-
The winds face inwards, in a counterclockwise motion at 30 degree angles to the
isobars
Longwaves may flow at what speed? - ANSWER-Longwaves may be stationary
How fast may the jet stream be moving between longwaves? - ANSWER-May be
flowing at 100 km
What charts can the jet stream be viewed in? - ANSWER-500 mb charts
What does the red dashed line on a 500 mb chart represent? - ANSWER-Represents a
longwave trough
What is a rex block? What weather accompanies it? - ANSWER-Rex blocks are
characterized by a high pressure system located pole-ward of a low-pressure system.
Unsettled, stormy weather is usually found near the low pressure while dry conditions
are typical with the high-pressure. Strong, particularly persistent, rex blocks cause
flooding near the low-pressure part of the block and short-term drought under the high
pressure part.
How does a cold front form? What does it look like before passing, while passing, and
after passing for; winds, temperature, pressure, clouds, precipitation, and visibility? -
ANSWER-Cold front form by the steep front forcing warm air upward rapidly. This leads
south or southwest winds before passing, gusty, shifing winds during, and west or
northwest winds after passing. Warm temp before, sudden drop during, and steadily
dropping after. Pressure falling steadily before, minimum, then sharp rise during, and
rising steadily after. Clouds increasing Ci, Cs and Cb, during TCu or Cb, and after Cu or
Sc. Precipitation is short period of showers before, heavy showers with lightning during,
QUESTIONS AND ANSWERS 100%
CORRECT
Air pressure - ANSWER-The mass of air above a given level
How does atmospheric pressure change with height? - ANSWER-Atmospheric pressure
always decreases with increasing height
What is wind and what causes it? - ANSWER-It is the movement of air, it is caused by
the uneven heating of the earth's surface
What is constant in a sea-level pressure chart? - ANSWER-Constant height
What is constant in an upper level or isobaric chart? - ANSWER-Constant pressure
surface (500 mb), high heights correspond to higher than normal pressures at given
latitudes and vice versa
What do isobars on a constant height chart look like? - ANSWER-The isobars represent
variations in horizontal pressure at that altitude. An average isobar at sea level would be
about 1000mb, at 3000m (10,000ft) about 700 mb, and at 5600m (18,400ft) about 500
mb
What is an isobaric surface? - ANSWER-Surface of constant pressure
What happens to the isobaric surface because of the changes of air density? -
ANSWER-Because of the changes of air density, the isobaric surface rises in warm,
less dense-air and lowers in cold, more dense air.
How high is the tropopause? What is its pressure? What weather system will you find
there? - ANSWER-36,000 ft. 250 mb, and you will find the jet stream
How high are winds aloft? What is the pressure at that altitude? - ANSWER-18,000 ft
and 500 mb
How high is the boundary layer? What is the pressure at that altitude? What weather will
you find there? - ANSWER-2,000-3,000ft, 920 mb. You find clouds there
How high is the surface layer? What is the pressure at that altitude? - ANSWER-30-100
ft and 1000 mb
, What is geostrophic wind? - ANSWER-Above the level of friction, air initially at rest will
accelerate until it flows parallel to the isobars at a steady speed with the pressure
gradient force (PGF) balanced by the Coriolis effect
What direction is cyclonic flow? - ANSWER-Counter-clockwise
What direction is anticyclonic flow? - ANSWER-Clockwise
Wind aloft flow what direction between isobars? - ANSWER-Parallel to isobars
Winds at the surface flow what direction? - ANSWER-Flow at 30 degree angels to the
isobars
In a high pressure system at the surface, what direction do the winds flow? - ANSWER-
The winds face outwards, in clockwise motion at 30 degree angles to the isobars
In a low pressure system at the surface, what direction do the winds flow? - ANSWER-
The winds face inwards, in a counterclockwise motion at 30 degree angles to the
isobars
Longwaves may flow at what speed? - ANSWER-Longwaves may be stationary
How fast may the jet stream be moving between longwaves? - ANSWER-May be
flowing at 100 km
What charts can the jet stream be viewed in? - ANSWER-500 mb charts
What does the red dashed line on a 500 mb chart represent? - ANSWER-Represents a
longwave trough
What is a rex block? What weather accompanies it? - ANSWER-Rex blocks are
characterized by a high pressure system located pole-ward of a low-pressure system.
Unsettled, stormy weather is usually found near the low pressure while dry conditions
are typical with the high-pressure. Strong, particularly persistent, rex blocks cause
flooding near the low-pressure part of the block and short-term drought under the high
pressure part.
How does a cold front form? What does it look like before passing, while passing, and
after passing for; winds, temperature, pressure, clouds, precipitation, and visibility? -
ANSWER-Cold front form by the steep front forcing warm air upward rapidly. This leads
south or southwest winds before passing, gusty, shifing winds during, and west or
northwest winds after passing. Warm temp before, sudden drop during, and steadily
dropping after. Pressure falling steadily before, minimum, then sharp rise during, and
rising steadily after. Clouds increasing Ci, Cs and Cb, during TCu or Cb, and after Cu or
Sc. Precipitation is short period of showers before, heavy showers with lightning during,
