The Nature of Storms Chapter 13

How many thunderstorms are happening right now around the world?

What’s a Severe Thunderstorm Winds of 50mph or more http://www.youtube.com/watch?v=3_e4yidYXHg&feature=related Hailstones measuring 0.75 inches http://www.youtube.com/watch?v=DcvduJanqJc http://www.youtube.com/watch?v=wZr8jXo1Uso Produce a tornado http://www.youtube.com/watch?v=sxkK9k84Udw&feature=related 10,000 in the US every year

Supercell Thunderstorm 2,000-3,000 a year Single HUGE thunderstorm Do the most damage Whole cloud is rotating Entire center of cloud= updrafts http://www.youtube.com/watch?v=UygT5N7Rgg8&feature=fvst http://www.youtube.com/watch?v=RW2y76xRaLs&feature=relmfu

Tornadoes Begin with air moving on the surface. Storm updrafts pick this air up Air begins to stretch out More stretching = Faster air Mesocyclone

Profile of a Tornado Form in front of cold fronts Form in southwest winds Travel to the northeast http://www.youtube.com/watch?v=fNi-ofz8trw&feature=related http://www.youtube.com/watch?feature=fvwp&NR=1&v=VQDkmziz1n8 http://www.youtube.com/watch?v=IUTQI52Vhg8&feature=fvsr http://www.youtube.com/watch?v=Cv9n-2Wpe2g&feature=related

Record Breakers Longest Touch-Down Most Tornadoes Tri-State Tornado Deadliest Longest Path On the ground for 219 miles (3.5 hours) Most Tornadoes Super Outbreak of 1974 148 tornadoes 315 fatalities 5,000 injured

Fujita Tornado Intensity Scale Used after the tornado has occurred Based upon damage caused Old version = misleading Doesn’t differentiate between structures Enhanced: Differentiates between structures

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Severe Thunderstorm Hazards 1). Lightning 2). Tornadoes 3). Flash Flooding

Lightning When there is lightning it is not safe to be outside; you could be struck. 80% of victims are males between the ages of 15-40.

Lightning Myths 1). It can’t occur without rain 2). Rubber soles of shoes or car tires can protect you 3). People can carry an electrical charge 4). Heat lightning means the thunderstorm is far away so you cannot be struck by lightning. 5). All lightning strikes the ground.

How does lightning work? During a thunderstorm, particles at the bottom of clouds take on a negative charge. More positive by the Earth. Electrical current, in the form of lightning, passes down to the ground Picks up a positive charge (Like a hand) Returns to cloud. http://regentsprep.org/Regents/physics/phys03/alightnin/default.htm

Most Lightning Strikes When it comes to being a human lightning rod Roy C. Sullivan is the iron clad holder of the title. Roy C. Sullivan was a U.S. forest ranger in Shenandoah National Park in Virginia and it seemed that having an electric personality prerequisite for his job. Lightning strike #1 came in 1942 in a fire lookout tower. Lightning strike #2 came in 1969when he was in his truck. Lightning strike #3 came in 1970 in his front yard. Lightning strike #4 came in 1972 in a ranger station. Lightning strike #5 came on August 7, 1973 while he was in his car. Lightning strike #6 came on June 5, 1974 in a campground. Lightning strike #7 came on June 25, 1977 while fishing.

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Flash Flooding Causes the most deaths out of all thunderstorm hazards 3 Ways for Flash-Flooding to Occur 1). Heavy Rains in a small area 2). Great volume of rain in a short time 3). Urban areas receiving lots of rain in a short time

Flash Flood Videos http://www.youtube.com/watch?v=vfT5dEKaUdk http://www.youtube.com/watch?v=Q0MGB7RtfCU&feature=fvst http://www.youtube.com/watch?v=wSw3FChSn_0&feature=related

Hurricanes Require Warm Ocean Water Occur in Late Summer Coriolis Force Causes Rotation

Hurricane Comic Strip You are going to have a comic square for each of these stages of a hurricane Each square should have some words or a picture that help you distinguish between stages Make them Funny…But Appropriate!! Remember….Comics Should Be Entertaining We will share 

Model For Your Comic Strip You Comic Strip Should Have Four Boxes

Hurricanes Stages 1). Tropical Disturbance 2). Tropical Depression 3). Tropical Storm 4). Hurricane

Tropical Disturbance Band of thunderstorms Located in the tropics Air rises because It is warm Waves

Next Stages Tropical Depression When a tropical disturbance reaches warm ocean water Wind speeds = 37 mph Tropical Storm Wind is moving up to 74mph Hurricane Wind is traveling faster then 74mph

Tropical Storm vs Hurricane http://www.youtube.com/watch?v=e_pYLGWLiic http://www.youtube.com/watch?v=EiNyAsSmI4s http://www.youtube.com/watch?v=QDFK40UMotc&feature=related http://www.youtube.com/watch?v=s76Qn7bpCsQ

Put the four stages of a hurricanes lifecycle in order Try to do this without any notes!! Put the four stages of a hurricanes lifecycle in order

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Names/Stages of a Hurricane “Hurricane" is given to systems that develop over the Atlantic or the eastern Pacific Oceans. In the western North Pacific and Philippines, these systems are called "typhoons" In the Indian and South Pacific Ocean, they are called "cyclones". Tropical Disturbance Band of thunderstorms Located in the tropics Air rises because It is warm Waves Tropical Depression When a tropical disturbance reaches warm ocean water Wind speeds = 37 mph Tropical Storm Wind is moving up to 74mph Hurricane Wind is traveling faster then 74mph

Parts of a Hurricane Eye: Center of the rotating storm Calm High Pressure: Air is sinking Eyewall: Location of the fastest winds Air is rising

Hurricane Death How do hurricanes lose energy? Move over land → lose moisture Move over colder water → lose heat supply

Saffir-Simpson Hurricane Scale Rates hurricanes based upon current conditions A hurricane moves through different levels throughout its life. 1-5 scale Based upon storm surge and pressure Saffir–Simpson Hurricane Scale Category Wind speed Storm surge mph (km/h) (kn) ft (m) Five ≥ 156 (≥ 250) (≥ 136) > 18 (> 5.5) Four 131–155 (210–249) (114–135) 13–18 (4.0–5.5) Three 111–130 (178–209) (96–113) 9–12 (2.7–3.7) Two 96–110 (154–177) (83–95) 6–8 (1.8–2.4) One 74–95 (119–153) (64–82) 4–5 (1.2–1.5) Additional classifications Tropical storm 39–73 (63–117) (35–63) 0–3 (0–0.9) Tropical depression 0–38 (0–62) (0–34) 0 (0)

Hurricane Destruction 1). Storm Surge 2). Wind Damage 3). Flash Flooding

Storm Surge Rise in sea level Caused by hurricane force winds Looks like a wall of water rushing in http://www.youtube.com/watch?v=nV6Qtrt2CNQ http://www.youtube.com/watch?NR=1&v=FOkyNq1eMvs Causes 90% of all hurricane deaths

Instant Flooding Hurricanes produce a lot of rain Causes Flash Flooding A lot of rain in a small amount of time Worse if combined with storm surge http://www.youtube.com/watch?v=3ItWEgfLwEA http://www.youtube.com/watch?v=-Kou0HBpX4A&feature=fvwrel

Wind Damage 75-150 mph winds These change in intensity depending on your location and the path of the hurricane http://www.youtube.com/watch?v=RIRodRRFu4s

Watches vs Warnings Watch Warning Specific Area Possibility of coastal areas being struck 36 hour notice Warning More Severe Hurricane force winds are expected to arrive Less then 24 hr notice

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Reoccurring Weather Floods: Abundance of water When storms hang around Droughts: Lack of rainfall Extended period with no rain or below average rainfall Result of high pressure systems

Temperature Extremes Heat Waves Cold Waves Extended Period of Above Normal Temperature Associated with High Pressure Systems High Humidity Cold Waves Extended Period of Below Normal Temperature High Pressure System of Polar Origin Wind Chill: How cold does it feel Combo of cold air and wind

Extra Credit Question What is the name of the tornado that crossed the three states and caused the most deaths? What three states did it cross?