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StormsWhat is a storm? A violent disturbance in the atmosphere.

What is a storm? Involves sudden changes in air pressureCause rapid air movementConditions that bring one kind of storm in one area often cause other kinds of storms in the same areaA thunderstorm is a small storm often accompanied by heavy precipitation and frequent thunder and lightening.A thunderstorm forms when warm, humid air rises rapidly within a cumulonimbus cloud.

Types of severe stormsThunderstormsTornadoesSnowstormsHurricanes

Torrential DownpoursStrong winds at greater than 58 miles per hourHail inch diameter (or larger)Frequent lightningSevere Thunderstorms6Issued by National Weather ServiceThis means that conditions are favorable for a thunderstormLength is multiple hours.Severe Thunderstorm Watch7Issued By Local Weather ServiceMeans a severe storm has been spotted by doppler radarUsually lasts for only an hourSevere Thunderstorm Warning8LightningA sudden spark or energy discharge, caused when electric discharges jump between parts of a cloud, nearby clouds, or between a cloud and the ground.

Because a lightening bolt can heat the air near to it close to 30,000 C, it causes the air to expand explosively. Thunder is the sound of the explosion. Since light travels faster than sound you see lightening flash then you hear thunder.9

10Temperatures of over 30,000C (much hotter than Suns surface)Heated air expands suddenly and explosively making a sound of thunder.

Properties of a Lightning11Stay indoors, away from doors and windows.

Avoid objects that conducts electricity, such as metal objects and bodies of water.

Do not seek shelter under the trees. Do not use phones with cords.

Remember: Cars are pretty safe

Thunderstorm/Lightning Safety12Why do we see lightning before we hear thunder?Because light travels much faster than sound.Tornadoes

Tornado Alley14A tornado is a rapidly whirling, funnel shaped cloud that reaches down from a cloud to touch Earths surface.

What is a tornado?15How are tornadoes formed?Same system that produces thunderstorms can produce tornadoes.

Late in the day, when earths surface is very warm, convection (the flow of heat through a material, causing hot parts to rise and cooler parts to sink) can get very strong. This can lead to a tornado.

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17Tornado WatchConditions are favorable for a tornado to formTornado WarningA tornado has formed.18Tornado Happenings 1. When the updraft in a convection cell is really strong, the air rushes in from all sides at high speeds.

19Tornado Happenings 2. Air curves into a spin. This lowers the pressure even more. Air rushes in even faster, and the pressure gets even lower, and so on. Like a skater who pulls her arms in close to her sides. The tornado spins faster and faster.

203. As the tornado gets stronger, a funnel forms that can destroy anything in its path. The center of the tornado can reach speeds of 500 kilometers per hour (about 300 miles per hour) or more.

Tornado Happenings 21Where Do Tornadoes Happen?Tornadoes happen where dry, cold air masses mix with moist, warm air masses. More tornadoes occur in the United States than in any other country, especially in the area known as TORNADO ALLEY.22A Famous TornadoGrand Island, NebraskaJune 3, 1980

23On June 3, 1980, a series of tornadoes devastated the city of Grand Island, Nebraska. Seven tornadoes hit within a three hour period. The storm did massive damage and closed the city down for three days.

24Tornadoes AlleyAbout 800 tornadoes every year in the United States.

Tornadoes SafetyThe safest place to take a shelter is in a storm shelter or the basement of a well-built building.

http://environment.nationalgeographic.com/environment/natural-disasters/forces-of-nature/25All year round, most precipitation begins in clouds as snow.

If the air is colder than 0 degrees all the way to the ground, the precipitation falls as snow.

What is a snowstorm?26Snowstorm Safety

Try to find a shelter from the wind.Cover exposed parts of your body and try to stay dry.Hurricanes

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Formation Regions

29What is a hurricane?A tropical storm that has winds of about 119 kilometers per hour or higher (200 miles per hour).

Storm usually doesnt last for more than 7-10 days.

As it moves inland it continues to move across the land but it begins to weaken

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Map SymbolsWhat Does a Hurricane Need in Order to Develop?

Needs warm watertime to growfavorable upper level winds in the troposphere. 32Typical Path

33Naming SystemA list of names from A-W (excluding Q)Alternate from male to female6 lists, repeated in cycleBig name storms retired, like KATRINA.34Hurricane WatchA hurricane poses a possible threat within the next 36 hoursHurricane WarningHurricane conditions expected within 24 hours35

The Saffir-Simpson Scalehttp://www.nhc.noaa.gov/aboutsshws.php Saffir-Simpson Wind Scale and Animationshttp://www.nhc.noaa.gov/surge/ Storm Surge Overview and AnimationsMEMORIZE!!!

Scale developed to categorize the hurricane based on winds speed.Hurricane SafetyBest plan is to evacuateTowns have voluntary evacuation during a watch, and some switch to mandatory during a warning.Plan early in advance37IF you choose to stay.Board all windowsPrepare Flashlights, avoid candlesStay tuned to radioStay indoors

http://environment.nationalgeographic.com/environment/natural-disasters/forces-of-nature/38The End

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