Weather4 days of Notes

Topic: Water Properties

Objectives: Day 1 of 4• I will know what weather is• I will understand humidity • I will know the difference between

evaporation and condensation• I will understand the water cycle

Quickwrite

Answer one of the following questions in 2-3 sentences:

• Have you ever visited someplace tropical like Texas, Florida or Hawaii? What did the air feel like?

• Why do you think water droplets form on the outside of a cold beverage?

Weather vs. Climate

• Weather changes from day to day

• One day it may be hot and dry, the next day cold, wet, and stormy

• Climate is the average weather for a particular

region over a long period of time

• As the saying goes, “Climate is what you expect and weather is what you get”

What is Weather?

• The state of our atmosphere on a ___to day basis, with respect to _______and precipitation

Answer Banktemperature

dayLiquid

AbsorbedPhase

released

Humidity

• If you remember, air is made up of 78% Nitrogen & 21% Oxygen

= Nitrogen = Oxygen• Air also contains

a small amount of water vapor

= Water Vapor (gas)

Humidity• Now lets

imagine we are some place tropical like Hawaii

• Here the air is more humid

• In other words there are more water molecules in the air!

• We say the air is more humid!!!!

Humidity

• Humidity is a measure of the amount of water vapor in the air

• Warmer air can hold more moisture or water vapor

• It also makes your hair curly!!!!

What is Humidity?

•A measure of the amount of _____in the air•Warmer air can hold more water vaporAnswer

Bankdecreasesurfacealtitudedroplets

Water vaporrises

condensation

Liquid(energy absorbed)

Gas

Evaporation

• Water exists in our atmosphere in a solid, liquid and gas form

• In order for a liquid like water to become a gas, energy must be absorbed!

• If enough energy is absorbed, the molecules can escape, and enter the gas phase

Gas

Liquid(energy absorbed)

Evaporation

Condensation• Think of Condensation

as evaporation in reverse

• If warm humid air comes in contact with a cold glass, water droplets form

• In other words, water has been converted from a gas (in the air) to liquid (on the glass)

• Clouds form the same way

Condesation

• If water vapor in the air cools, it will turn back into a liquid forming cloud droplets

• So, Condensation is the process by which water vapor in the air is changed into liquid water

Condensation

Liquid (heat released)

Gas(water vapor)

What is Evaporation and Condensation?

• Evaporation is a cooling process by which water is converted from a liquid into a ____ (water vapor)

• Energy is ____• Condensation is the process by

which water vapor in the air is changed back into _____water

• Energy is released

Answer BankEvaporation

gasContinuous

LiquidAbsorbed

Phase

The ocean absorbs

radiation (heat) from the sun

Evaporation Causes water

moleculesto rise

As water vapor rises it cools,

and condenses,turning back intoA liquid, forming

clouds

As the Clouds rise higher, they cool,

dropping Precipitation

(snow, hail, rain)

Stored water on land flows back to the

ocean through rivers or groundwater

Water is now stored in the atmosphere

The Water Cycle

What is the Water Cycle?

• The _______movement of water on, above, and below the surface of the Earth through evaporation and condensation

Answer BankEvaporation

gasContinuous

LiquidAbsorbed

phase

Summarize:

• _______ is when water is converted from a liquid into a gas

• As humid air rises, it cools and _____ forming clouds

• Clouds and fog are made of water droplets that form as a result of ______

• If you live in Hawaii, the air is more _______ because there is more _____ ____in the air

Answer BankHumid

condensesWater cycle

WeatherCondensationWater vapor

Topic: Dew Point and Clouds

• Objectives: Day 2 of 4– I will know what the dew point is

– I will know what a cloud is and how we classify them

– I will know how condensation Nuclei provide the seed for water droplets to form

Quickwrite

Answer one of the following questions in 2-3 sentences:

• What kinds of shapes do clouds have?

• Why do we always get fog in the morning?

• What do you think clouds are made of?

Dew Point

• Remember, humidity is the amount of water vapor in the air

• When warm, saturated, humid air comes in contact with cooler surfaces, dew forms as a result of condensation

• Features such as grass, leaves, and spider webs often contain dew

• At night, the temperature drops

• Sometimes the temperature will fall below the dew point temperature

• If this happens, you might wake up to dew on your grass or fog

At the dew point temperatureFog, clouds or dew form

What is the Dew PointDew Point?

• The temperature air needs to cool for _______to begin

• If the temperature is _____then Dew Pt., then clouds, fog or Dew will form

Answer Bankdecreasesurfacealtitudedroplets

Water vaporrises

Condensationbelow

Clouds

• Clouds are small collections of small water droplets or ice crystals that form through condensation or freezing

• Clouds can form either high in our atmosphere or near the surface

• Compared to rain droplet, cloud droplets are small

• Millions upon millions of cloud droplets make up one cloud

Cloud Droplet

Rain Droplet

Cloud Droplet

What is a Cloud?

• A collection of small water _____ or ice crystals suspended in the air,

• They form from ______when the temperature is below the_______

Answer BankDew point

surfacealtitudedroplets

Water vaporrises

Condensationbelow

Cloud Classification

• Clouds are classified by their shape and altitude

• The 3 basic cloud types are: stratus, cumulus, and cirrus

Stratus

Cumulus

Cirrus

Stratus Clouds• Clouds with flat

bottoms that are found close to the surface

• “Stratus” means sheet like or layered

• Right above fog are stratus clouds

Stratus

Cumulus Clouds• Cumulus clouds

resemble big fluffy cotton balls

• They have a flat base that show a well-defined condensation level Cumulus

Cirrus Clouds• Cirrus clouds have

feathery appearance and are composed of ice crystals

• They form at high elevations

• Cirrus clouds are seen during sunny skies and are a sign that bad weather is on it’s way

Cirrus

What are the 3 types of clouds?

• Stratus- low _____ clouds, with layered, sheet like shape

• Cumulus-middle altitude clouds, with flat, _____shape

• Cirrus- ____altitude clouds made of ____ crystals, giving them a feather like shape

Answer Bankwedging

Icecombination

Altitudehigh

convergencefluffylifting

Stratus

Cumulus

Cirrus

Condensation Nuclei• Our atmosphere

contains billions of particles of dust, pollen, ice, salt and other materials

• These condensation nuclei float through our air and provide the seed needed for water vapor to condense and make water droplets

• Water molecules are attracted to these condensation Nuclei

• It takes thousands of these tiny water droplets to make one rain droplet

Condensation Nuclei

Droplets ofWater form

Water Molecules Are attracted to these

Condensation nuclei

• Condensation Nuclei are small particles of dust, pollen or salt

• Water is attracted to these particles

• These particles provide the seed need to make cloud droplets and eventually rain

Condensation Nuclei

Condensation Nuclei

Cloud Droplet

Rain Droplet

What are Condensation Nuclei?

• Small solid particle (dust, pollen, salt) in the atmosphere that provides the _____on which water vapor condenses

Answer Bankdecreasesurfacealtitudedroplets

Water vaporrises

Condensationbelow

Summarize

• Draw and label the 3 types of clouds:

• If the outside air temperature is ______ the dew point temperature, ______, or fog will form

• ______ ______ are small particles in the atmosphere that provide the surface for water vapor to condense

Answer BankDew

belowWater vapor

CumulusCirrusStratus

Condensation Nuclei

????

????

????

Topic: Cloud Formation

• Objectives: Day 3 of 4– I will know the 4 ways clouds can form

– I will understand coalescence and the 4 kinds of precipitation

– I will know the different severe low pressure systems and their charateristics

Answer one of the following questions in 2-3 sentences:

• How do you think rain drops form in clouds?

• Why do mountains receive more rain and snow?

Quickwrite

Cloud Formation• When air rises it cools, condenses and

reaches the DEW POINT temperature• Whenever humid air rises, clouds form

Dew Point Temperature

Temperature air needs to cool In order for clouds,

fog & dew to form

As air rises it cools!!!!!

Convective Lifting

Dew Point Temperature

Orographic Lifting

Mountains force air to rise, as it rises it cools and condenses!!!!!

Dew Point Temperature

Temperature air needs to cool In order for clouds,

fog & dew to form

As air rises it cools and condenses!!!!!

Covergence

Frontal Wedging

Dew Point Temperature

Temperature air needs to cool In order for clouds,

fog & dew to form

Cold Heavy AirWarm Light Air

As air rises it cools and condenses!!!!!

What caused this band of clouds to form over the

equator?

Frontal Wedging

• Cold air lifting warm air, resulting in clouds

How did this cloud form?2 ways

Convergence -2 air masses coming togetherOrographic Lifting - mountains lifting air

What are the 4 ways clouds can form?

• When air rises it cools, condenses forming water droplets or clouds

• 4 ways air rises: - Orographic lifting -mountains lift air

- Frontal_____- warm air is lifted above colder air

-____________- air converges and is forced upward

- Convective______- hot air rises over hot land

Answer Bankwedging

combinationAltitude

highconvergence

fluffylifting

Precipitation• Any moisture that

falls from the air to Earth’s surface is called Precipitation

• The 4 major types of precipitation are rain, snow, sleet, hail

• Any _______ that falls from the air to Earth’s surface is called Precipitation• 4 types exist: ______, snow, sleet, hail

What is Precipitation?What is Precipitation?

Answer BankAnswer Bankwedgingwedging

rainrainAltitudeAltitudemoisturemoisture

convergenceconvergencefluffyfluffy

Coalescence

• Ever wonder how rain drops form?

• They form through a process call coalescence

• A rain drop is the combination of smaller cloud droplets coming together to form a large rain droplet

• As larger droplets grow, they fall picking up even more small droplets in the process

Coalescence• How do we go

from a small cloud droplet, to a typical, large raindrop

Coalescence

Cloud DropletsRain Droplet

Gravity pulls the heavyLarge raindrop down

• The formation of a large rain droplet by the ______ of smaller droplets

What is CoalescenceCoalescence??

Answer Bankwedging

Icecombination

Altitudehigh

convergencefluffylifting

• Severe weather is any weather that may cause property damage or loss of life

• Severe weather may include large quantities of rain, lightning or hail, strong winds, or tornadoes

• Severe weather causes billions of dollars in damage each year

Severe Weather

Thunderstorms

• A thunderstorm is accompanied by rain, thunder, lightning, and strong winds

• A thunderstorm is an extreme low pressure system

Tornadoes

• A tornado is the most violent, and shortest lived severe storm or low pressure system

• It is basically a destructive rotating column of air that has very high winds producing a funnel shaped cloud

Tornadoes

• The winds of a tornado may reach speed of over 400 kilometers!

• Usually everything in a tornado’s path is destroyed

• A scale to measure tornadoes is the Fujita scale with and F1 being the weakest and an F5 being the strongest

Tornado Formation

• A tornado is the result of warm tropical air coming up from the gulf of Mexico meeting cold dry air coming down from Canada

Warm, humid Warm, humid air mass from air mass from Gulf of MexicoGulf of Mexico

Cold, dry Cold, dry air mass from air mass from

CanadaCanada

Hurricanes

• A hurricane is a tropical storm

• Hurricanes do not have warm and cold fronts

• Hurricanes develop over warm tropical water where evaporation release a tremendous amount of heat and energy

Hurricanes

• Hurricanes are about 700 kilometers in diameter and can have winds that can reach up to 275 kilometers an hour along the eye wall

• Hurricanes are the most destructive storms on earth

Hurricanes form of Hurricanes form of the coast of Africa the coast of Africa where warm ocean where warm ocean temperatures cause temperatures cause massive amounts of massive amounts of

evaporationevaporation

The Tradewinds The Tradewinds blow theblow the

hurricane hurricane toward the gulftoward the gulf

of Mexico & the of Mexico & the United StatesUnited States

The evaporation of warm ocean water feeds hurricanes

Hurricane Katrina on its

path of destruction towards

New Orleans

What are 3 types of severe low What are 3 types of severe low pressure systems?pressure systems?

• A ______ storm consists of rain, strong winds, lightning, and rain

• A ______is a destructive, rotating funnel shaped column of air that has winds up to ______km

• A ______ is a severe storm that develops over _____ oceans with winds up to 275 km/h

Answer Banktropicalcumulus

400hurricanethunderstratuswarm

tornado

Summarize

• When mountains cause clouds to form it is called _______ _______

• When clouds form between to air masses it is called _______ ______

• ________ is the formation of a large rain droplet by the combination of smaller droplets’

• The largest and most severe storm is a _____

• The most violent and shortest lived storm is a _______

Answer BankTornado

Orographic liftingCollision

Coalescence

Hurricane

Frontal wedging

Topic: Fronts & High/Low Pressure

• Objectives: Day 4 of 4– I will know the difference between a cold

and warm front– I will understand the difference between

high and low pressure systems– I will know how wind flow from high

pressure to low pressure

Quickwrite

Answer one of the following questions in 2-3 sentences:

• If a warm air mass meets a cold air mass, which one is lighter?? Which one is heavier??

• If warmer air can hold more water, what type of air mass do you think creates more rain-cold or warm air mass????

How Air Moves• If you recall, The sun drives

our winds due to the uneven heating of earth

• This unequal heating creates our global wind patterns

• Remember, hot equatorial air moves to the cold poles by convection, resulting in our wind

• Then, the Coriolis Effect causes our wind to curve and spin

• But, air also moves as a result of pressure differences in our atmosphere

How Air Moves

• Air moves from areas of high pressure (H), to areas of low pressure (L)

• During High Pressure, air

sinks• During Low Pressure, air rises

High vs. Low

Low PressureAs air rises, it spins Counter clockwiseAs a result, cloudy stormy weather forms

High PressureAs air sinks, it spins clockwiseAs a result sunny, clear weather forms

Where in the U.S. is sunny High pressure? Where in the U.S. is stormy Low pressure?

Where is the Stormy Weather?

Isobars are lines Isobars are lines of equal pressureof equal pressure

During High Pressure, During High Pressure, (H) air spins clockwise (H) air spins clockwise

as it sinksas it sinks

During Low Pressure, (L) airDuring Low Pressure, (L) airspins Counter-Clockwise spins Counter-Clockwise

as it sinksas it sinks

High vs. LowHigh vs. Low

High vs. LowHigh vs. Low• Wind flows from High Pressure to ____Pressure• The greater the pressure difference, the faster

the windHigh = 1020mb Low = 990mbAir_____, spinning clockwise creating

Sunny clear weather

Air_____, spinning counter-clockwise creating, cloudy

stormy weather

Answer Banklow

cumulusSinks

thunderstratuswarm rises

Air Masses• When air doesn’t move, it starts to take on a

characteristic temperature and humidity for that region

• An air mass is a large body of air throughout which temperature and moisture content are similar

Maritime-Maritime-air masses air masses

formformover the oceanover the oceanCold & HumidCold & Humid

Polar Polar Continental-Continental-

Air Masses form Air Masses form over landover land

Cold & DryCold & Dry

TropicalTropical--air masses air masses

formformover the oceanover the oceanWarm & HumidWarm & Humid

Tropical-Tropical-air masses form air masses form over the oceanover the oceanWarm & HumidWarm & Humid

Maritime-Maritime- air masses air masses

formformover the oceanover the oceanCold & HumidCold & Humid

TropicalTropicalContinental-Continental- air masses formair masses form

over the landover the landWarm & DryWarm & Dry

• A large body of air throughout which temperature and moisture content are________

• 4 types:-Polar Continental –cold and dry because they form over land-Maritime – cold and humid because form over cold _______

-Tropical – Warm, humid that forms over tropical water

-Continental Tropical –Hot and dry because they form over warm land

What is an Air Mass?What is an Air Mass?

Answer Bank

tropicaloceanfunnel

thundersimilarwarm

moisture

Fronts• When 2 air masses meet

they don’t mix, they form FrontsFronts

• Why?!• Because they have

different Temperatures and Densities

• A cold air mass is dense and does not mix with a warm air mass

• There are 2 types of fronts: Cold Front and a Warm Front

Cold Fronts• When a cold air mass

overtakes a warm air mass, a cold front forms

• The moving, heavier, cold air lifts the warm air

• If the warm air is moist, Clouds will form

• Large cumulus and cumulonimbus form along cold fronts

• Cold front is the boundary where cold air pushes warm air out of the way and brings colder weather and cumulus clouds

Cold Fronts

• The side with the “teeth” has the warmer air

• The colder air is pushing the warmer air up

A Cold Front Approaching:Notice the large cumulus clouds

Warm Fronts• When a cold air mass

retreats from an area, a warm front forms

• This warmer, lighter, less dense air rises over the cooler air

• A warm from has a gradual slope, with clouds that form as the warm air rises along the front

• A warm front can cause rain, and even sever thunderstorms

• A warm front is defined as the area or zone where a warm air mass is replacing a cold air mass

Warm FrontWarm Front

On a weather map, Colder temperatures are on the side of the semi circles

Where is the warm front? Where is the cold front?

Isobars are lines Isobars are lines of equal pressureof equal pressure

What is the difference between What is the difference between Cold Front and Warm Front?Cold Front and Warm Front?

• Cold front is the boundary where cold air ______warm air out of the way and brings colder weather and ______ clouds

• A warm front is the boundary where a ____ air mass is replacing a cold air mass and _______ clouds form as warm air is forced upward

Answer Bankpushescumulus

Sinksstratuswarmrises

Summarize

• High pressure, air is _____ & the weather is ____

• Low Pressure, air is _____ & the weather is _____

• At location D and B you are experiencing _____

Answer BankWarm

Cold (2)low

risingsinking

rainCloudy rainy

highSunny, clear

_______air_______air_______air

______Clouds

______Clouds

_______Front_______FrontFront Movement