Earth Science CET (Weather)

It describes the short-term atmospheric conditions

in a specific place at a specific time. It includes conditions

such as temperature, humidity, precipitation, cloudiness,

visibility, and wind.

Weather

It can change minute-by-minute, hour-by-hour, and day-

by-day.

Examples: A rainy day, a snowstorm, a sunny afternoon, or

a cold snap.

Weather

It refers to the long-term average of weather

patterns in a particular region over a significant period,

typically 30 years or more. It encompasses the statistical

weather information that describes the variation of

weather at a given place over a period.

Climate

It is observed over long periods, from decades to

millennia.

Examples: The Mediterranean climate (hot, dry summers

and mild, wet winters), the Arctic climate (cold and dry), or

the tropical rainforest climate (hot and wet year-round).

Climate

They are the movement of air from high-pressure areas to

low-pressure areas and are a critical component of weather

and climate systems.

Winds

Types of Winds:

1. Local Winds

2. Prevailing Winds

Caused by differential

heating of land and sea. Sea breezes blow from the sea to

the land during the day, while land breezes blow from the

land to the sea at night.

Sea Breezes and Land Breezes

Occur in mountainous

regions. Valley breezes blow uphill during the day, and

mountain breezes blow downhill at night.

Mountain and Valley Breezes

This occurs on summer days because land heats up

faster than the sea. As the warm air over the land rises (since

it’s less dense than cooler air), cooler air from over the ocean

moves in to take its place. This movement of warm and cool

air creates the refreshing sea breeze we often feel near

coastlines.

Sea breeze

This occurs at night when the land cools

down faster than the sea. As the cooler air over the land sinks

(since it’s denser than warmer air), it moves toward the ocean.

This movement creates a gentle breeze blowing from the land

toward the sea.

Land breeze

Warm valley, cooler air overhead

Low pressure in valley causes wind to flow upward

Valey Breeze

Cool valley, warmer air overhead

High pressure in valley causes winds to flow downward

Mountain Breeze

These are dry, cold prevailing winds that

blow from the east. They originate from the polar highs

(areas of high pressure) around the North and South Poles.

Polar easterlies flow toward lower latitudes.

Polar Easterlies

Also known as prevailing westerlies, these

winds blow from the west toward the east in the middle

latitudes (between 30 and 60 degrees latitude). They

originate from high-pressure areas in the horse latitudes

and steer extratropical cyclones.

Westerlies

These steady winds blow from the northeast

in the Northern Hemisphere and from the southeast in the

Southern Hemisphere. They are associated with the Hadley

Cell and are great for sailing ships near the equator.

Trade Winds

These fast-flowing, narrow air currents

occur at high altitudes (around the polar front). They

influence weather patterns and can impact aviation routes1.

Polar Jet Streams

Narrow bands of strong winds in the upper

levels of the atmosphere, typically occurring at the

boundaries of different air masses.

Jet Streams

Most prominent types of jet streams:

1. Polar Jet Stream

2. Subtropical Jet Stream

They are seasonal wind patterns that cause dramatic

changes in precipitation. They are characterized by a shift in

prevailing winds that typically brings significant rainfall.

Monsoons

During summer, landmasses heat up

faster than the oceans, creating low-pressure areas over

the land. Moist air from the oceans is drawn inland, leading

to heavy rainfall.

Summer Monsoon

During winter, the land cools down faster

than the oceans, creating high-pressure areas over the

land. Dry, cool air flows from the land to the ocean,

resulting in dry conditions over the land.

Winter Monsoon

The Philippines’ two distinct

wind patterns and seasons that occur annually.

1. Amihan

2. Habagat

Also known as the Northeast monsoon, Amihan

brings cool northeast winds. It is characterized by

moderate temperatures, little or no rainfall in central and

western Luzon and Visayas, and prevailing winds from the

east. On the east coast of Luzon, it brings drizzling rainfall

and squalls. Amihan typically starts around November or

December and lasts until May or June, although there can

be variations from year to year.

Amihan

The Southwest monsoon, Habagat, brings hot

and humid weather, frequent heavy rainfall, and prevailing

winds from the western parts. The switch between Amihan

and Habagat

Habagat

Types of cyclonic

weather systems that form in tropical and subtropical waters:

1. Tropical storms

2. Tropical depressions

It is a cyclonic weather system with

sustained winds of up to 38 mph (62 km/h).

It has a well-defined center of low pressure and is

associated with organized thunderstorms. The wind

circulation is cyclonic (counterclockwise in the Northern

Hemisphere and clockwise in the Southern Hemisphere).

Tropical Depression

A tropical storm is a more intense cyclonic weather system

with sustained winds ranging from 39 to 73 mph (63 to 118

km/h).

It has a well-defined center and more organized structure

than a tropical depression. Tropical storms can bring heavy

rain, strong winds, and coastal flooding.

Tropical Storm

It is a large air mass that rotates around a strong

center of low atmospheric pressure.

Cyclone

In the Northern

Hemisphere, cyclones rotate at?

Counterclockwise

In the

Southern Hemisphere, they rotate at what? These weather systems can bring heavy rain and

strong winds.

Clockwise

It is a type of storm called a tropical cyclone, which

forms over warm tropical or subtropical waters. These

powerful weather systems are characterized by sustained

winds of 74 miles per hour (119 kilometers per hour) or greater

12.

Hurricane

They are usually accompanied by heavy rain, thunder,

and lightning. They can cause significant damage to coastal

areas and sometimes extend into temperate latitude.

Hurricane

It is a tropical cyclone that develops between 180°

and 100°E in the Northern Hemisphere. These powerful

storms produce sustained hurricane-force winds of at least 119

km/h (74 mph). They typically occur in the western Pacific

Ocean or the northern Indian Ocean and can intensify as sea

surface temperatures rise.

Typhoon

It is a belt of low

pressure that encircles the Earth near the equator where the

trade winds of the Northern and Southern Hemispheres come

together.

Intertropical Convergence Zone (ITCZ)

The ITCZ is generally located near the equator, but its

position shifts north and south with the?

Seasons

The zone moves toward the warmer hemisphere, typically

shifting northward during the Northern Hemisphere's

summer and southward during the Southern Hemisphere's

summer. This migration follows the _______ and

can range between about 5°N and 5°S to as much as 25°N

and 25°S in extreme cases.

Solar declination

It is characterized by high rainfall and thunderstorm

activity due to the rising, moist air that cools and

condenses to form clouds and precipitation.

ITCZ

They are common in the ITCZ, leading to

intense, localized thunderstorms.

Cumulonimbus clouds

The ITCZ is where the trade winds from the Northern

Hemisphere (northeasterly trade winds) and the Southern

Hemisphere (southeasterly trade winds) _______.

Converge

The ITCZ is a region of relatively

calm winds with weak and variable wind patterns is also known as?

Doldrums