What is weather?What is weather? Refers to the state of the atmosphere at a Refers to the state of the atmosphere at a

specific time and place.specific time and place.What are some of the factors that affect the What are some of the factors that affect the

weather?weather?

Air TemperatureAir Temperature

Temperature is the Temperature is the measure of the measure of the average amount of average amount of motion in particles.motion in particles.

WindWind a natural movement of a natural movement of

air of any velocity; air of any velocity; especiallyespecially :: the earth's the earth's air or the gas air or the gas surrounding a planet in surrounding a planet in natural motion natural motion horizontally horizontally

HumidityHumidityThe amount of water vapor present in the airThe amount of water vapor present in the air

Relative HumidityRelative Humidity -is a measure of the -is a measure of the amount of water vapor present in the air amount of water vapor present in the air compared to the amount needed for compared to the amount needed for saturation at a specific temperaturesaturation at a specific temperature

CloudsClouds Masses of small water droplets or tiny ice Masses of small water droplets or tiny ice

crystals that float in the air.crystals that float in the air. Three main types are cirrus, cumulus, and Three main types are cirrus, cumulus, and

stratus.stratus. Other clouds are a mixture of these three Other clouds are a mixture of these three

main types.main types.

CirrusCirrus

Cirro- means “curled” Cirro- means “curled” or “feathery”or “feathery”

Form highest in the Form highest in the sky; are made up of sky; are made up of ice crystals; and ice crystals; and appear as curls, tufts, appear as curls, tufts, or wisps.or wisps.

Usually signal the end Usually signal the end of clear weather.of clear weather.

CumulusCumulus Cumulo- means Cumulo- means “heaped” or “piled”“heaped” or “piled”

Cottony clouds with flat, Cottony clouds with flat, usually gray bases, and usually gray bases, and puffy, bright tops.puffy, bright tops.

Usually signal good Usually signal good weather, but if weather, but if atmosphere is unstable, atmosphere is unstable, can build into towering can build into towering clouds that produce clouds that produce showers and showers and thunderstorms.thunderstorms.

StratusStratus Strato- means Strato- means “layer-like” or “layer-like” or “sheet-like.”“sheet-like.”

Low-lying, dull-Low-lying, dull-colored clouds colored clouds that form in that form in layers or layers or sheets.sheets.

Usually bring Usually bring drizzling rain or drizzling rain or light-falling light-falling snow.snow.

AltoAlto

A prefix meaning A prefix meaning “middle range of “middle range of clouds “ and used clouds “ and used to describe clouds to describe clouds that lie from that lie from 6,500-18,500 ft. 6,500-18,500 ft. (1,980-5,640m).(1,980-5,640m).

NimbusNimbus

A rain cloudA rain cloud

Other Cloud TypesOther Cloud Types

Cirrocumulus Cirrostratus

Stratocumulus Cumulonimbus

More Cloud TypesMore Cloud Types

Altocumulus

Altostratus

Nimbostratus

PrecipitationPrecipitation

Water that falls from the cloudsWater that falls from the clouds Air temperature determines the form of Air temperature determines the form of

precipitation that fallsprecipitation that falls 4 main types of Precipitation: Rain, Sleet, 4 main types of Precipitation: Rain, Sleet,

Snow and HailSnow and Hail

Types ofTypes of PrecipitationPrecipitation

RainRain SleetSleet

SnoSnoww

HailHail

Air MassesAir Masses

A large body of air that A large body of air that has properties similar to has properties similar to the part of the Earth’s the part of the Earth’s surface over which it surface over which it develops. develops.

Air Mass MapAir Mass Map

FrontsFronts

A boundary between two air A boundary between two air masses of different density, masses of different density, moisture, or temperature. moisture, or temperature.

Cold FrontCold Front

Warm FrontWarm Front

Occluded FrontOccluded Front

Stationary FrontStationary Front

Severe WeatherSevere WeatherThunderstorms

Lightning

Tornadoes

More Severe WeatherMore Severe Weather

Hurricanes Blizzards

Severe Weather SafetySevere Weather Safety

Watches- conditions are favorable Watches- conditions are favorable Warnings- conditions already existWarnings- conditions already exist Examples- Tornadoes, Flooding, Examples- Tornadoes, Flooding,

Thunderstorms, Blizzards, Winter Mixes and Thunderstorms, Blizzards, Winter Mixes and HurricanesHurricanes

LightningLightning

Tornado AlleyTornado Alley

Fujiti ScaleFujiti Scale

Weather MapWeather Map

HurricaneHurricane

Hurricane ScaleHurricane Scale

Hurricane CharleyHurricane Charley

Two sources of Two sources of forecasting weatherforecasting weather– Data collected from Data collected from

upper atmosphereupper atmosphere– Data collected on the Data collected on the

Earth’s surfaceEarth’s surface

Weather Station ModelWeather Station Model

IsobarsIsobars

Isobars-connect points Isobars-connect points of the “same”of the “same”

Examples: Examples: temperature and wind temperature and wind speedspeed

The further away the The further away the lines the lower the lines the lower the wind speedwind speed