WHAT IS WEATHER The state of the atmosphere

WHAT IS WEATHER? The state of the atmosphere at a given place and time 1) Temperature 2) Humidity 3) Air Pressure (atmospheric pressure) 4) Wind

What Makes up Weather? • Whether you see a weather report or look at a weather map… • The following elements make up weather • • Heat (temperature) Atmospheric (air) pressure Wind (speed and direction) Moisture (humidity)

Weather & Energy • Obviously, MANY FORMS of ENERGY play a role in and affect severe weather patterns that happen all over the world… – But how and why does severe weather happen? – Is all weather “severe”? – Why are some forms of severe weather common in some places and not in others? • In order to understand how and why severe weather happens, first we have to understand what weather is and how it works!

WHAT IS CLIMATE? Weather conditions at a location over a long time period 1) Polar – little rainfall, severe cold 2) Temperate – a lot of rainfall, more mild to cool temperatures 3) Arid – little rainfall, dry, hot 4) Tropical – a lot of rainfall, humid, hot 5) Mediterranean – a lot of rainfall during winter, dry summers 6) Mountains – wet, cold winters, mild summers

Atmosphere Weather The state of the atmosphere at a given place and time Thin envelope of gases that surrounds the planet Weather vs. Climate –Small picture, short-term –Constantly changing, hour to hour, day to day –Temperature, cloudiness, rainfall, wind speed and direction, humidity, air pressure Climate Weather conditions at a location over a long time period –Big-picture, long-term

ednesday/Thursday 2/25 -2/26/2015 Agenda: Weather and Climate Unit ØNotes: Weather and Climate ØActivity: Weather and Climate Foldable ØActivity: Heat Transfer Review Homework/Classwork ØHeat Transfer Review Packet due Friday 2/27/2015 for 30 Points

What Causes the Weather to Change from Day to Day? • Earth’s atmosphere being heated by the Sun’s rays and being mixed and moved about by wind causes changes in weather

WEATHER FUELED BY: THE SUN

Heat vs. Temperature Heat: the total kinetic energy (energy of motion) of all the molecules that make up a substance Temperature: a measure of the degree of hotness or coldness in a substance Measured in °F or °C

MEASURING TEMPERATURE THERMOMETER

Severe Weather Tornado with lightning in KS Definition: A weather condition likely to cause hardship and destruction Hurricane forming Heavy ice during an Ice Storm Types: • • Blizzards Flooding Extreme Heat Ice Storms Thunderstorms Tornado Hurricane

Severe Weather Statistics • According to the National Weather Service (NWS) in 2007 in the U. S. alone, severe weather caused more than 515 deaths and close to $13 billion in damage.

How Does Severe Weather Happen? • Lightning – – Definition: A visible electrical discharge produced by a thunderstorm. • How does LIGHTNING form? – Forms when updrafts of air carry water droplets, which have a charge, upward to heights where some freeze into ice and snow • The discharge may particles. occur within or between – The particles form a clouds, between the cloud and air, between – As these particles begin to fall a cloud and the ground back to Earth, charges within the or between the ground cloud become mixed. and a cloud. – The differences in charge are released as lightning.

So What Kind of has hit Arizona? SEVERE WEATHER In 2006, there were 21 deaths, 26 injuries and $159. 4 million in property damage reported for the state of AZ. NOAA National Weather Service

AZ Lightning

Lightning September 2, 1994 • Severe thunderstorms ripped through the greater Phoenix area with winds in Chandler estimated between 60 -65 mph. • Extensive street flooding was reported around the Valley with water 35 ft. deep in some underpasses. • Numerous trees, both medium and large were blown down. • A house caught fire from lightning. • 70 power poles were blown down in the Queen Creek area. • Thunderstorm winds blew out a store front window causing an estimated $6000 damage. • A 22 -year-old man was killed by lightning in Tempe while trying to retrieve his vehicle in a parking lot. http: //www 4. ncdc. noaa. gov/cgi-win/wwcgi. dll? ww. Event~storms

How Does Severe Weather Happen? • Thunderstorm – – Definition: A local storm produced by a cumulonimbus cloud and accompanied by lightning and thunder. • How do THUNDERSTORMS happen? – Form when warm air rises from Earth's surface and moves upwards quickly into the colder levels of the atmosphere. – If conditions are right, tornadoes can form from this rapid updraft (upward moving air). – Normally, the result is rain, wind, lightning, and thunder. – “Thunder” is the noise lightning makes as it travels through the air.

Monsoonal Thunderstorm in AZ - 2006