Transcript wind

Weather...
You can’t see me, but you feel me, you can’t touch
me, but I can touch you. I have been called the
“Breathe of the Gods”, or the killer and giver of
life, gentle and fierce, friendly and enemy, angry
and happy. The Native Americans called me
Moriah, and Snow Eater (Chinook). The Japanese
call me Kaze and in Russia I am called Veter. I can
shatter homes, or wake a child from a peaceful
sleep or bring relief in times of need. I can spread
the most dreaded diseases or bring a welcome
freshness. What am I?
Weather is....

The current state of the
atmosphere...what is happening right
now
Main points to remember as we
learn about weather:
The sun warms the earth’s surface and
therefore all the air above the surface
 The earth is warmed most at the equator and
least at the poles---why?
 The air above land is warmed more quickly
than air above water.
 Warm air expands and rises, creating an area
of low pressure; cold air is dense and sinks,
creating an area of high pressure

All weather is a result of humidity,
condensation and pressure.
Types of Air Masses
Continental: dry
Maritime: wet

Polar: cold
Tropical: warm
continental polar (cP): cold & dry (Canada)
 continental tropical (cT): warm & dry (Mexico)
 maritime polar (mP): cold & wet (north oceans)
 maritime tropical (mT): warm & wet (south
oceans)
Label on your map…
Air Mass

Warm air= expanding or rising air=
leaves behind Low (L) pressure

Cold Air=sinking air= leaves an area
of High (H) pressure
Weather Fronts…

Fronts - the boundary between 2 air
masses
Warm Front
Warm Front: warm air slides over
departing cold air.
 Large bands of precipitation form

This is
the
symbol
on a
map for
a warm
front
Cold Fronts
This is the symbol
for a cold front
Cold air pushes under a warm air mass.
Warm air rises quickly.
 Narrow bands of violent storms form

Occluded Front
This is the
weather map
symbol for an
occluded front
2 air masses merge and force warm air
between them to rise quickly.
 Strong winds and heavy precipitation
will occur

Stationary Front
This is the
weather map
symbol for a
stationary front
Warm or cold front stops moving.
 Light wind and precipitation may occur
across the front boundary

QUIZ TIME!!!

Get a scrap piece of paper and number
1-3
What type of front(s) do you
see?
Answer…

Cold Front & Stationary Front
What type of front(s) do you
see?
Answer…

Cold Front
What type of front(s) do you
see?
Occluded Front
 Warm Front
 Cold Front

Reading a weather map
ISOBAR= connects areas of equal
pressure BAR comes from BARometric
pressure.
 We measure
wind pressure
with a
Barometer

Reading a weather map...

Isotherm: Connects areas of equal
temperature; therm means
temperature
Isotherms
Let’s practice…
Wind Movement
Uneven heating of the earth’s
surface causes some areas to
be warmer than others.
 As we know, warm always
follows cold to share it’s
warmth.
 When this happens in the
atmosphere, wind happens!

What causes winds?
A wind is a
horizontal
movement of air
from a area of high
pressure to an area
of low pressure
 It is this difference
in pressure that
makes the air
move=wind

Winds are measured
by direction and
speed
 The anemometer
is the tool we use to
measure this
 Wind chill=↑ cooling
the wind causes

Local Winds


The land cools and heats faster than the ocean.
Water holds heat longer than land, and takes longer
to heat or cool.
Sea Breeze


During the day, the
land gets hotter
faster than the water.
The heated air rises,
leaving behind an area
of low pressure.
Wind from the cooler
sea blows in to take the
place of that warmer
air.
These happen during
the day!
Land Breezes
At night the lands cools off faster than
the sea. Cool air sinks creating an area
of high pressure. Wind blows from
the land to the sea.
Temperature

Air temperature is shown in Fahrenheit
degrees by the number to the upper
left of the circle.
75
Pressure

Pressure—measured in mb (millibars)—
is given by the number to the upper
right of the circle
194
Dew Point Temperature

The dew point temperature in
Fahrenheit degrees is shown to the
lower left of the circle.
57
Wind Direction and Speed


Wind direction is shown
by an “arrow” going
into the circle. The
example shows wind
blowing from the lower
right, so this is a
southeast wind.
Each long “feather”
represents 10 mph and
each short “feather 5,
so the wind speed is 25
mph.
Cloud Cover
The amount of the circle that is filled in
indicates how much of the sky is
covered by clouds.
 It may range from “clear” (left) to
“overcast” (right).

“Present Weather”

When rain, snow, or
other forms of
precipitation, lightning,
and special weather
conditions exist, these
are shown by symbols
to the left of the circle
between air
temperature and dew
point temperature
rain
showers
thunderstorm
*
snow
Try to interpret this station
model
1.
2.
3.
4.
5.
6.
Temperature:
Pressure:
Dew Point:
Clouds:
Wind:
Precipitation:






76 o F
138 mb
55 o F
cloudy
from NE at
20 mph
rain
Weather Station (not on the TV)
Clouds

In order for clouds to form, air must be at its dew point (temperature at which
air is saturated). Water vapor condenses on small particles called
condensation nuclei.

Cirrus—light, thin, feathery (fair weather clouds)

Cumulus—puffy white clouds

Stratus—low gray clouds
Cloud Formation
Clouds form when water vapor
condenses on dust & salt particles in
the air
 The temperature in which condensation
begins is called the dew point

TYPES OF CLOUDS

Cirrus Clouds: wispy, feathery clouds
Form only at high levels,
therefore are made of ice
crystals
Types of Clouds

Cumulus Clouds: are puffy white
cotton ball looking clouds
Cumulonimbus Clouds
These are
thunderstorm
clouds
 Brainpop

Types of Clouds

Stratus Clouds: clouds that form in flat
layers- cover all or most of the sky and
are low level clouds