Download MET403-05

Winds within a high
Winds blow
clockwise and
outwards.
H
Regional Gliding School
Area of Divergence
A flow of air outwards from a region
and is associated with highs. Sinking air
compensates for the flow of air outwards.
Regional Gliding School
Winds within a low
Winds blow counterclockwise and
inwards.
L
Regional Gliding School
Area of Convergence
The flow of air into an area of low
pressure is accompanied by rising air
allowing the excess accumulation to
escape.
Regional Gliding School
Land Breeze
• Blows at night
• Land becomes cooler faster than water
causing a high over the land
• Wind blows from the land (high pressure
area) towards the water (low pressure area)
Regional Gliding School
Land Breeze
Warm Sea causes
Low Pressure
over the sea.
Cool land causes
High Pressure
over the land
L
H
Wind blows from
high to a low
Sea Breeze
• Occurs during the day
• Land heats faster than water causing a low
over the land
• Wind blows from the sea (high pressure
area) towards the land (low pressure area)
Regional Gliding School
Sea Breeze
Warm Land causes
Low Pressure
over the land
Cool Sea causes
High Pressure
over the sea
L
Wind blows from
high to a low
H
Confirmation
Stage
NOTE: You must use the buttons in the Confirmation Stage
Regional Gliding School
Meteorology
Winds
Let's try a few review questions on Meteorology:
Question #1 -
Match
A flow of air outwards from a region and
is associated with highs. Sinking air
compensates for the flow of air outwards.
The flow of air into an area and is
accompanied by rising air to permit
the excess accumulation to escape.
Regional Gliding School
A
Area of divergence
B
Area of convergence
A
Area of divergence
B
Area of convergence
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
That answer is correct.
Let's move on...
Try other match
Flying Scholarship Program
That answer is correct.
Let's move on...
Try other match
Meteorology
Winds
Let's try a few review questions on Meteorology:
Question #2 -
Regional Gliding School
At night land cools faster then water forming
a higher pressure area. The result is wind
blowing from the land to the sea. This is
known as
.
A
Land breeze
B
Sea breeze
C
Wind shear
D
Jet stream
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
That answer is correct.
Let's move on...
Diurnal Variations
• Daily variation of the wind
• Caused by surface heating during the day
• Causes turbulence in lower levels which transfers
the stronger upper level winds to the surface
• This causes surface winds to veer an increase
during the day
• Surface winds back and decrease during the
evening when daytime heating stops.
Regional Gliding School
A rapid and brief increase in
the wind speed. It is often
associated with rapid fluctuations
in the wind direction.
Regional Gliding School
SPEED (KNOTS)
GUSTS
30
25
Rapid peaks and lulls in
the wind speed
20
15
10
5
TIME
Regional Gliding School
Similar to a gust but of
longer duration. Caused by the
passage of a fast moving cold
front or a thunderstorm.
Regional Gliding School
SQUALLS
SPEED (KNOTS)
AT LEAST TWO MINUTES
30
25
20
15
10
5
SUDDEN INCREASE LASTING
FOR AT LEAST TWO MINUTES
TIME
Regional Gliding School
Mechanical Turbulence
Friction between the air and surface
features of the earth is responsible for the
swirling vortices of air called “eddies”.
Regional Gliding School
Tornadoes
Violent, circular whirlpools
of air associated with severe
thunderstorms and are very
deep concentrated lows.
Regional Gliding School
Veering and Backing
• Veer
– the wind changes direction clockwise
– wind veers and increase as altitude increases
• e.g. 270° to 300 °
– wind veers and increases during the day
• Back
– the wind changes direction counter-clockwise
– wind backs and decreases as altitude decreases
• e.g. 90° to 60°
– wind backs and decreases at night
Regional Gliding School
Wind Shear
Sudden “tearing” or “shearing” change in
wind speed or direction. Can be very violent.
Jet Stream
Narrow bands of exceeding high speed
winds known to exist in higher levels of the
troposphere at altitudes ranging from 20,00040,000 feet. Wind speed is usually 100-125
knots but may get as high as 250 knots.
Regional Gliding School
NOTE: You must use the buttons in the Confirmation Stage
Regional Gliding School
Meteorology
Winds
Let's try a few review questions on Meteorology:
Question #3 -
Regional Gliding School
What is a rapid and brief increase in the
wind speed?
A
Squall
B
Gust
C
Wind shear
D
Jet stream
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
That answer is correct.
Let's move on...
Meteorology
Winds
Let's try a few review questions on Meteorology:
Question #4 -
Regional Gliding School
When happens to the wind as an aircraft
ascends?
A
Veer and increase
B
Veer and decrease
C
Back and increase
D
Back and decrease
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...
Flying Scholarship Program
That answer is correct.
Let's move on...
Meteorology
Winds
Congratulations!!
You have now completed the Winds lesson of the Meteorology Module.
Of course, this lesson is always available to you for future reference if
required.
You are now ready to move along to the next Meteorology lesson you
have not completed or to any other module you wish. You can advance
to the Self Test Module if you feel ready to challenge the final exam.
Good Luck!
Regional Gliding School