Starter: What is the difference between a cold front and a warm front? Explain how a front is different from an air mass 2/2/ Severe Weather 2/2/15 Practice : Notes glue here when done Application: Severe Weather ws Connection:  Why do hurricanes only occur in certain places?  Where are thunderstorms most likely to occur? Exit : What are the characteristics of an air mass that form over the Gulf of Mexico? Explain how this air mass would affect us in Texas. Severe Weather

February 2, 2015 AGENDA 8.10 A Recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents. Supporting Standard C Identify the role of the oceans in the formation of weather systems such as hurricanes. Supporting Standard 1 Starter 2. Notes 3. Ws 4. Exit

DateLecture/ Activity/ Lab Page Table of Contents 1/26 Wind, Climate, and Ocean Currents /27 Convection and Ocean Currents /28 Fronts and Air Masses /29 Pressure and Atmospheric Movement /2 Severe Weather and Precipitation

Types of Precipitation/

The Whole Reason for Weather zThe sun is the driving force behind the movement of moisture and weather. zThe radiant energy from the sun transfers heat to the Earth and changes the water into solid, liquid and gas.

Moisture ☼ Evaporation is caused by heating water molecules until it turns into a gas. zWater molecules enter the air (atmosphere) through the process of evaporation Ice forms as vapor rises Liquid forms as vapor sinks

Humidity (GAS) z the amount of water vapor or moisture in the air. zAs air temperature increases, the amount of water the atmosphere can hold increases.

Rain (LIQUID)  Ice melts as it falls through warmer air.  Cloud droplets have little mass, so they may come together (condense) and become too heavy to stay in the cloud.  They then fall to Earth with the force of gravity. Shape of rain drops

Frozen Precipitation  Forms when water vapor (gas) changes directly into a solid. Sleet begins as snow, a shallow layer of warm air partially melts then it refreezes into an ice-pellet. Hail stones accumulate layers of ice as they move up and down within a cloud; eventually hailstones get too heavy and fall. Snow are ice crystals & comes in a variety of shapes depending on temperature.

Distribution of precipitation in the US

El Niño zEl Niño is characterized by unusually warm temperatures on the sea surface in the Pacific Ocean at the equator. zThis warming changes the flow patterns of the Trade winds and ocean currents and affects world- wide rainfall by causing flooding or droughts. zIn the continental US, temperatures in the winter are warmer than normal in the North Central States, and cooler than normal in the Southeast and the Southwest.

La Niña zLa Niña events follow the El Niño events and has the opposite effects on the ocean surface and weather patterns. zLa Niña forms unusually cool temperatures in the Pacific ocean at the equator (shown in blue). zDuring a La Niña year, winter temperatures are warmer than normal in the Southeast (USA) and cooler than normal in the Northwest.

Hurricane zA large, swirling, low- pressure system that forms over tropical oceans with wind speeds up to 156 miles per hour. zBegin as a group of thunderstorms moving over tropical waters zMost powerful storms on Earth yIn the Pacific Ocean called typhoons yIn the Indian Ocean called cyclones

Thunderstorms zContain strong winds, lightning, and thunder and heavy rain. zHappens when warm water evaporates, rises rapidly and then it cools, condenses and creates a Cumulonimbus cloud. zWarm and cold air move throughout the clouds swiftly; creating strong winds.

Tornadoes zViolent, spinning column of wind that has high wind speeds and touches to the ground. zUsually starts out as a funnel cloud that pokes through the bottom of a cumulonimbus cloud (thunderstorm) and hangs in the air. zCalled a tornado when it touches Earth’s surface.

Lightning zElectric discharge that takes place between a positively and negatively charged area in a cloud zCan happen between two clouds or between the Earth and a cloud zReleases energy when it strikes

Thunder zThe result of the energy from a lightning strike. zEnergy is transferred to the air and causes air to expand in waves of sound.

Starter: What is the difference between a cold front and a warm front? Explain how a front is different from an air mass 2/2/ Severe Weather 2/2/15 Practice : Notes glue here when done Application: Severe Weather ws Connection:  Why do hurricanes only occur in certain places?  Where are thunderstorms most likely to occur? Exit : What are the characteristics of an air mass that form over the Gulf of Mexico? Explain how this air mass would affect us in Texas. Severe Weather