Why and How Typhoons works

1. TYPHOON
Presenter: Orlean Troy Agad

2. OBJECTIVES OF THE TOPIC
After completing this lesson, the students should be able to:
1. Describe what a typhoon is,
2. Explain how typhoons develop,
3. Discuss what causes them,
4. Identify it’s effects and impacts, and
5. Discuss its possible mitigation and preventive measures.

3. KEY TERMS & DEFINITIONS
• Monsoon - a seasonal prevailing wind in the region of
South and Southeast Asia, blowing from the southwest
between May and September and bringing rain (the wet
monsoon ), or from the northeast between October and
April (the dry monsoon ).
• Trough - an elongated area of relatively low pressure
extending from the center of a region of low pressure.
• ITCZ - The Intertropical Convergence Zone, or ITCZ, is
the region that circles the Earth, near the equator, where
the trade winds of the Northern and Southern
Hemispheres come together.
• Ocean Basin - any of several vast submarine regions
that collectively cover nearly three-quarters of Earth’s
surface.
• Natural Disasters - also referred to as natural hazards
are extreme, sudden events caused by environmental
factors such as storms, floods, droughts, fires, and
heatwaves.

4. KEY TERMS & DEFINITIONS
• Low Pressure Area - a place where the atmospheric
pressure is lowest compared to the surrounding area.
• Clusters - represent groups whose mean air mass
transport fields are statistically different from one another
and correspond to the types of high and low pressure
patterns seen on daily weather maps.
• Vortex - refers to the counter-clockwise flow of air that
helps keep the colder air near the Poles.
• Hazards - a source or a situation with the potential for
harm in terms of human injury or ill-health, damage to
property, damage to the environment, or a combination of
these.
• Mitigation- defined as “sustained action that reduces or
eliminates long-term risk to people and property from
natural hazards and their effects.”

5. WHAT IS TYPHOON?
• A typhoon is a type of large storm system having a
circular or spiral system of violent winds, typically
hundreds of kilometers or miles in diameter. The winds
spiral around a region of low atmospheric pressure.
• "Typhoon" is the name of these storms that occur in the
Western Pacific. "Hurricane" is the name given to these
storms in the Atlantic Ocean and Eastern Pacific. In the
Indian Ocean, they are called "Tropical Cyclones".

6. WHAT IS TYPHOON?
• The energy that powers typhoons comes from the
evaporation of warm ocean water. The water vapor rises to
the top of the typhoon along the sides of the eye, then
condenses into clouds. Warmer ocean water produces
more powerful typhoons, which can grow into "super
typhoons".
• For stronger typhoons, a characteristic structure called the
"eye" forms when the maximum wind speeds exceed about
85 miles per hour, or 140 kilometers per hour. The eye is a
region of clear air with no clouds, and is a few tens of
kilometers in diameter.

7. HOW TYPHOONS ARE
FORMED?

8. Typhoons are categorized into five:
Category 1
TROPICAL DEPRESSION
(TD)
• sustains winds between
119 and 153 km/hour.
• It is the first notable
stage in the formation of
a hurricane.
Category 2
TROPICAL STORM
(TS)
• It has winds between 154
and 177 km/h.
• a tropical storm is a
system of intense
thunderstorms that
progressively intensifies.

9. Typhoons are categorized into five:
Category 3
SEVERE TROPICAL
STORM (STS)
• a typhoon or tropical
cyclone with maximum
wind speed of 87 to 117
kph or 48 - 63 knots.
Category 4
TYPHOON (TY)
• An intense typhoon
sustains high winds of
210 to 249 km/h and is
classified as a category -
5 storm, which carries the
highest element of risk.

10. Typhoons are categorized into five:
Category 5
SUPER TYPHOON
(STY)
• A violent typhoon which
characterized by winds
exceeding 249 km/h