Tropical cyclones form over warm ocean waters with surface temperatures above 26°C. As warm air rises from the ocean surface, it creates a low pressure area at the center. Surrounding winds begin to rotate inward due to the Coriolis effect from the Earth's rotation. Thunderstorms form in a spiral pattern around the low pressure center, and if conditions continue to allow for further development, a tropical cyclone will form. Once over land, tropical cyclones weaken due to a lack of warm ocean waters providing energy and moisture.

1. GOOD DAY!

3. HOW DO TROPICAL
CYCLONES FORM?

4. Tracks (paths) of four tropical cyclones that entered the PAR in the past years. Study
and analyze the maps.

5. Questions
◦1. Where did the tropical cyclones form? On land
or in the ocean?
◦2. In what direction did the tropical cyclone move?
◦3. Which part of the Philippines was hit by the four
tropical cyclones?
◦4. In the case of Agaton, Yoyong, and Huaning,
where did they die out? Near land or in the middle
of the ocean?

7. What are the requirements for a tropical cyclone
to form?
SEA TEMPERATURE ABOVE
26°C
LIGHT WIND SHEAR &
CONVERGING WINDS
EARTH’S ROTATION
THUNDERSTORM CLUSTER

9. Questions
1. Where did the tropical cyclones form?
2. Which is a better source of water vapor?
3. Where do you think would evaporation be greatest?
4. What can you say about the temperature of the bodies of
water in the vicinity of the Philippines?
5. What should be the temperature of ocean water for the
tropical cyclones to form?
6. Why is the Philippines prone to typhoon?

10. Water evaporates from the
ocean surface and comes into
contact with a mass of cold air,
forming clouds.
A Low Pressure Area
develops at the center.
Winds form around the
column.
As pressure in the center (eye)
weakens, the speed of the
wind around it increases.
TROPICAL
CYCLONE
FORMATION

11. What are the effects of Landforms
and Bodies of water to Typhoons?

13. Questions
1. What happened to typhoon when reaches a landmass?
2. Why do typhoon weaken when reaches a landmass?
3. What happened to typhoon when stayed on a body of
water for a long time?
4. Why do typhoon intensify in a body of water?

14. Effects of Bodies of water to Typhoons

16. TROPICAL CYCLONE
•Is a rapidly rotating system characterized by:
A LWO PRSURESE CTEENR
A LOW PRESSURE CENTER
SONTRG WNDIS
STRONG WINDS
SPRAIL AANRRGEMENT OF
THNDUERTOSRMS
SPIRAL ARRANGEMENT OF
THUNDERSTORMS
HAVEY RINAS
HEAVY RAINS

17. Arrange the following phenomena that describe the formation
of tropical cyclone.
1. C. Occurrence of warm water in the
Pacific Ocean, usually a temperature
of 26.5⁰C or above.
2. A. Warm ocean water heats up the air
above it and warm air rises resulting in
a low – pressure area. Air in the
surroundings will then move.
3. E. Water in the rising warm air soon
condenses and heat is given off. The heat
makes the air rise even more, and air in the
surroundings will keep coming in.
4. B. Air starts to spin.
5. D. A tropical cyclone is born.
A. Warm ocean water heats up the air above
it and warm air rises resulting in a low –
pressure area. Air in the surroundings will
then move.
B. Air starts to spin.
C. Occurrence of warm water in the Pacific
Ocean, usually a temperature of 26.5⁰C or
above.
D. A tropical cyclone is born.
E. Water in the rising warm air soon
condenses and heat is given off. The heat
makes the air rise even more, and air in
the surroundings will keep coming in.

18. Multiple Choice
1. From what bodies of water do typhoons originate? A. ocean B. lakes C. rivers D.
streams
2. Name the agency of the government that monitors typhoon in the Philippines. A.
DOST B. PAGASA C. PHIVOLCS D. DENR
3. What is the name of the big body of water that is where almost all typhoon that pass
in our country? A. Indian Ocean C. Atlantic Ocean B. West Philippine Sea D. Pacific
Ocean
4. What happen to typhoon when it hits land? A. intensifies B. weakens C. become
stronger D. increase in speed.
5. What should be the temperature of ocean water for the tropical cyclones to form? A.
at least 15°C B. less than 26 °C C. more than 26 °C D. 20-25 °C
6. Why do tropical cylone usually weakens when reach land?
A. the wind spins faster B. decrease in moisture/water vapor
C. the direction change D. another LPA forms

20. ◦ circulation disturb weaken
◦Tropical cyclone air ocean
◦Water vapor winds
◦mountain ranges

21. Warm bodies of water, with at least surface temperature of
__(1) , is the main factor in the formation of a (2)__. The warm
air above the surface of the (3)__ builds and tends to rise up.
The surrounding (4)__ is forced to move in the direction where
the air is rising until it creates a cyclonic (5)__ that results in
tropical cyclone. On the other hand, landforms like a (6)__ , act
as an obstacle to traveling air masses forcing them to rise over
the peaks and tend to affect (7)__ direction and therefore, (8)__
the spin of a tropical cyclone. Tropical cyclone (9)_ or even die
out because of lack of (10)__ supply.

23. BIBLE VERSE OF THE DAY
◦1 Corinthians 15:33
◦33 Do not be misled: “Bad company corrupts good
character.”
◦Huwag kayong paloloko. “Ang masasamang kasama
ay nakakasira ng mabuting pagkatao.”

24. REVIEW

25. ◦1. What is the name of the tropical cyclone formed
in the northwestern part of the Pacific Ocean?
◦A. Hurricane
◦B. Tornado
◦C. Tsunami
◦D. Typhoon

26. ◦2. In what year did super typhoon Yolanda hit the
Philippines?
◦A. 2011
◦B. 2012
◦C. 2013
◦D. 2014

27. ◦3. In what direction does a tropical cyclone usually
move?
◦A. Northeast
◦B. Northwest
◦C. Southeast
◦D. Southwest

28. ◦4. What is the wind speed of severe tropical storm?
◦A. 62 – 88 km/h
◦B. 89 – 117 km/h
◦C. 118 – 220 km/h
◦D. more than 220 km/h

29. ◦5. During a typhoon, Public Storm Warning Signal
(PSWS) is issued over the affected area. What is the
impact of the wind when PSWS signal is 4?
◦A. No to light damage
◦B. Light to moderate damage
◦C. Moderate to heavy damage
◦D. Heavy to very heavy damage

30. ◦6. What should be done after a typhoon?
◦A. Store sufficient amount of food.
◦B. Always ready with the emergency kit.
◦C. Keep monitoring the typhoon’s movement.
◦D. Boil water before drinking as it may be
contaminated.

31. ◦7. What happens to a typhoon when it makes a
landfall?
◦A. gets weaker
◦B. stays longer
◦C. moves faster
◦D. gets stronger

32. ◦8. How do landforms affect typhoon?
◦A. no effect at all
◦B. increase wind direction
◦C. serve as a fuel to travelling air masses making
typhoon stronger
◦D. serve as an obstacle for travelling air masses
making typhoon weaker

33. ◦9.Which will occur as results of tropical cyclone?
◦A. strong wind, light rainfall, tornado, and tsunami
◦B. strong wind, heavy rainfall, flood, and storm surge
◦C. strong wind, heavy rainfall, storm surge, and
earthquake
◦D. strong wind, light rainfall, pyroclastic flow, and
earthquake

34. ◦10.Which statement is INCORRECT?
◦A. Warm bodies of ocean water are the main source in the
formation of typhoon.
◦B. Warm bodies of ocean water build up increasing the
wind speed of typhoon.
◦C. Air from surrounding areas with lower air pressure
pushes to the high-pressure area.
◦D. Tropical cyclone does not form in the South Atlantic
Ocean due to its lower temperature.

35. Activity: Tropical Cyclone Formation
1

36. 2

37. 3

38. 4

39. 5

40. THANK YOU!

41. ◦Assume that you are a meteorologist, report on how
a tropical cyclones develop.

42. RUBRICS
5 4 3 2
Organization Excellent
The presentation
was well
organized, well
prepared and easy
to follow.
Good
The presentation
had organizing
ideas but could
have been much
stronger with
better preparation.
Fair
There were
minimal signs of
organization or
preparation.
Poor
The presentation
lacked
organization and
had little evidence
of preparation.
Content Excellent
Presentation had
an exceptional
amount of
valuable material
and was extremely
beneficial to the
class
Good
Presentation had a
good amount of
material and
benefited the
class.
Fair
Presentation had
moments where
valuable material
was present but as
a whole content
was lacking.
Poor
Presentation
contained little to
no valuable
material.
Presentation Excellent
Presenters were all
very confident in
delivery.
Preparation is very
evident.
Good
Presenters were
occasionally
confident with
their presentation.
Fair
Presenters were
not consistent with
the level of
confidence/
preparedness they
showed the
classroom.
Poor
Presenters were
unconfident and
demonstrated little
evidence of
planning prior to
presentation.