Meteorologists study weather and use weather data to predict conditions. Weather is the current atmospheric conditions of an area, including factors like temperature, wind, and precipitation. Climate is the average weather of a region over a long period of time. Weather instruments and satellites provide accurate weather information that helps meteorologists make forecasts to inform public planning.

1. CHAPTER 19
WEATHER AND CLIMATE

2.  Weather satellites, computers, and other kinds
of weather instrument provide accurate
information about weather conditions.
 Meteorologists are people who study the
weather and use weather data to predict the
weather.
 Their forecasts help us plan our daily activities.
 Guide Questions:
 1.Have you ever wondered what the weather
will be on a certain day?
 2.You experience weather (yes or no) and
why?

3. WHAT DOES WEATHER MEAN?
 Weather is the condition of the atmosphere at
any given time and place.
 The chief elements of weather are
sunshine, temperature, air
pressure, wind, humidity (moisture), clouds
, and precipitation. All these elements change
frequently.
 Weather science is known as meteorology.
 This term comes from two Greek words
 Meteoros meaning ‘high in the air’
 Logos meaning ‘knowledge’

4.  Meteorologists in all parts every hour of what
the weather is where they are.
 Each country has typical or average weather.In
the Philippines, April and May are the warm
summer months, while July and August are the
rainy months.
 The average weather in a region over a period
of time is called climate.
 Climate is the weather condition of a place over
a long period of time.
 Thus weather is very variable and can be
described as fair, rainy, sunny, or stormy.

5. THE EARTH IS DIVIDED INTO THREE ZONES
 (1)The zone of tropical climate,
 (2)The zone of temperate climate,and
 (3)The zone of polar climate
 These climate zones are related to the angle at
which the sun’s rays strike the earth
 Thus the general descriptions of climate
conditions in these zones are as follows:
 1.Zone of tropical climate – hot humid climate
 2.Zone of polar climate – very cold climate
 3.Zone of temperate climate – mild climate

6. ELEMENTS OF WEATHER
 The earth’s surface absorbs heat but also radiates
some of this heat but also radiates some of this
heat.
 The sun’s energy that is absorbed by the earth is
spread throughout the atmosphere in
 Three basic ways: Conduction, Convection, and
Radiation
 Conduction is the direct transfer of heat energy
from one substance to another.
 Convection is the transfer of heat in a gas or liquid.
 Radiation is the transfer of heat energy in the form
of waves through a vacuum.

7. QUIZ
FILL IN THE BLANK
Write the group of words that will correctly
complete each sentence.
 1. m _ t e o ro l_ og_ _ _ t are people who study
_e __ _ i s
the weather and use weather data to predict the
weather.
 2.W_ a t h e_r_ is the condition of the
e ___
atmosphere at any given time and place.
 3.M_ t _ o r_o_ lo_ _ _ science that deals with
e_e _ g y
weather and climate conditions.
 4. m e t_e o ro s _ meaning high in the air
_ __ _
 5.L_ g o_s_meaning knowledge
o _

8.  6.The average weather in a region over a
period of time is called c_i _ _ _t _ _.
l ma e
 7.P_ e c i_ p i_ t_a t_ io n_ is
r __ _ _
rain, snow, sleet, hail or any other
moisture u c t fails.
o n d that i o n
 8.C_ _ _ _ _ _ _ _ _ is the direct transfer
of C o n energy from one substance to
heat e c t o n
another.
 9._ _a_ vi _ _ _i i o n is the transfer of heat
d at __
in a gas or liquid.
 10.R_ _ _ _ _ _ _ _ is the transfer of heat

9. TYPES OF CLOUDS
 Clouds have different shapes and sizes.
 Clouds are classified according to shape and
altitude.
 The main types of clouds are cirrus
clouds, cumulus clouds, stratus clouds, and
nimbus clouds.
 Cirrus clouds are fair-weather clouds. They
appear thin and curly.
 Cirrus means ‘feathery’. They consist of ice
crystals because they are formed under low
temperature at high altitudes.

10.  Cumulus means ‘piled’ or ‘heaped up’.
 Cumulus clouds look like heads of cauliflower
with flat bottoms.
 These clouds develop when rising columns of
moist air are cooled to the dewpoint
temperature.
 Stratus means ‘spread out’ or ‘stretched in
layers’.
 Unlike cumulus clouds, stratus clouds are only
a few hundred meters thick but may extend
over thousands of square kilometers.
 Nimbus means ‘rainy’.

11. AIR MASSES
 A cold air mass is turbulent because of the
many convection currents affecting it.
 The convection currents are caused by the
warming of the air when it comes in contact
with the ground.
 Warm air masses form very few convection
currents but form fog and low clouds close to
the ground.
 This condition develops because the air close
to the ground is cooled to a temperature near
its dew point.

14. AIR MASS BOUNDARIES
 A cold front forms when a mass of cold air
meets and replaces a mass of warm air.
 A warm front forms when a mass of warm air
overtakes a cold air mass and moves over it.
 A cold front travels faster than a warm front.
 When cold front overtakes a warm front, and is
rushed upward, an occluding front occurs.
 An occluded front produces less extreme
weather than a cold or a warm front.
 When a warm air masses meets a cold air
mass and no movement occurs, a stationary
front forms.

15. ENUMERATE THE FOLLOWING:
 1-4 types of clouds
 5-8 types of fronts
 9-10 two air masses
 Answers:
 1.Cumulus clouds 5.cold front 9.cold air masses
 2.Cirrus clouds 6.warm front 10.warm air masses
 3.Stratus clouds 7.occluding front
 4.Nimbus clouds 8.stationary front

16. STORMS AND TYPHOONS
 Thunderstorms are heavy rainstorms with
thunder and lightning.
 These storms can be violent.During a
thunderstorm, areas of positive and
negative electrical charges build up in the
storm clouds.
 Lightning is a sudden discharge or spark
of electricity between these cloud areas or
between a cloud and the ground.

17. THE CLIMATE OF THE PHILIPPINES
 The climate of the philippines may be
categorized into three:
 1.From March to May–warm and dry
seasons
 2.From June to November–rainy
seasons
 3.From December to February–cool
and dry seasons

18.  Tropical cyclones, which affect the Philippines
during the months of June to November, may
be classified into three categories depending on
the wind speed.
 1.Tropical depression–has a maximum wind
speed of less than 63 kilometers per hour(kph).
 2.Tropical storm–has a maximum wind speed of
63 to 118 kph.
 3.Typhoon–has a maximum wind speed
exceeding 118 kph.
 The Philippines Atmospheric, Geophysical, and
Astronomical Services Administration
(PAGASA)

19. WEATHER FORECASTING
 All over the world, weather stations keep track
of the presence of cyclones, anticyclones, and
weather fronts.
 This information is supplied to meteorologists in
local weather stations.
 The information received is put together or
summarized in a weather map.
 Stations with the same air pressure are joined
by a line.
 Such a line is called an isobar.

20. CLOUD SEEDING
 Cloud seeding is a method that is used to
control precipitation.
 This method uses silver iodide particles spread
in clouds to act as condensation nuclei.
 Cloud seeding helps disperse fog in airports
and, in dry areas, it induces rainfall and
snowball.
 It ha also been successful in reducing the
power of thunderstorms and hurricanes.
 Cloud seeding causes droplets of water to

21. QUIZ
MULTIPLE CHOICE:ON THE LINE BEFORE EACH NUMBER, WRITE
THE LETTER THE CORRESPONDS TO THE CORRECT ANSWER.
 ____1.Which refers to the general conditions of
b.
temperature and precipitation over a large area over a
long period of time?
 a.atmosphere c.latitude
 d. b.climate d.weather
 ____2.What occurs due to the unequal heating of the air?
 a.conduction c.radiation currents
 b. b.precipitation d.convection currents
 ____3.What instrument is used to measure air pressure?
 a.altimeter c.psychomotor
 a. b.barometer d.thermometer
 ____4.What term refer to an area where two different air
masses meet?
 a.front c.low pressure area
 b.isobar d.high pressure area

22.  ____5.Which of the following people study weather?
c.
 a.astronomers c.meteorolgists
 b.geologists d.seismologists
 ____6.What kind of front occurs when a cold front overtakes a warm
b.
front?
 a.cold c.stationary
 b.occluded d.warm
 ____7.What happens to air above a surface when the surface
a.
absorbs more heat?
 a.becomes warm c.becomes dense
 b.becomes cooler d.becomes humid
 b.
____8.Which layer in the upper atmosphere absorbs ultraviolet rays?
 a.hydrogen c.water vapor
 b.ozone d.carbon dioxide
 a.
____9.Which area of high pressure contains cold, dry air?
 a.anticyclone c.hurricane
 b.cyclone d.tornado
 ____10.Which type of cloud is feathery and occurs only at very high
a.
altitudes?
 a.cirrus c.cumulus
 b.cumulonimbus d.stratus

23. SEATWORK/HOMEWORK
ANSWERS:
Pages 281 to 283