Presentation on theme: "Tornadoes Defined as a violently rotating column of air extending from a thunderstorm to the ground."— Presentation transcript:
1 TornadoesDefined as a violently rotating column of air extending from a thunderstorm to the ground.
2 Tornadoes Occur in many parts of the world Found most frequently in the United States east of the Rocky MountainsMost frequent during the spring and summer months.An average of 800 tornadoes are reported nationwide each year80 deaths and over 1,500 injuries average per year.Capable of tremendous destruction with wind speeds of 250 mph or more.Damage paths can be in excess of one mile wide and 50 miles long.
5 Tornado Formation Cont’d Change in wind direction along with an increase of speed causes horizontal spinning effect.Rotating air tilts becoming vertical, forming funnel shape.Funnel extends to the ground becoming the Tornado.“Wall cloud”-slow rotating cloud, parent to the Tornado.
6 When and Where they occur Mainly in the US but can occur anywhereSouthern states- March-MayNorthern states- Summer months.Wayne CountyAll CountiesHistorical Tornado Statistics for Southeast Lower Michigan(updated through 2001 season)
7 “Watches” versus “Warnings” Many people confuse their meanings“Watch”- tornadoes are possible in your areaA tornado watch is issued by the National Weather Service when tornadoes are possible in your area. Remain alert for approaching storms. This is time to remind coworkers where the safest places within your office are located, and listen to the radio or television for further developments.“Warning”- tornadoes have been sighted by weather radar
8 Tornado Clues Look out for: Dark, often greenish sky Wall cloud Large hailLoud roar; similar to a freight trainTornadoCluesA lower cloud base in the center of the photograph identifies an area of rotation known as a rotating wall cloud. This area is often nearly rain-free. Note rain in the background.Moments later a strong tornado develops in this area. Softball-size hail and damaging "straight-line" winds can occur with this storm.
9 TornadoVariationsSome tornadoes may form during the early stages of rapidly developing thunderstorms.Occasionally, two or more tornadoes may occur at the same time.Tornadoes may appear nearly transparent until dust and debris are picked up.Waterspouts are weak tornadoes that form over warm water.
10 Different types of Tornado The “Wedge” TornadoStraight on sides- not funnel shaped.Not stronger than a funnel shape but cover larger areas causing more damage.
11 Different types of Tornado Another wedge with a different appearanceOften blamed for striking without warning.Appear as a boiling well of fog as they are positioned close to the rain wall.The rain stops and the tornado appears
12 Different types of Tornado Classic funnel but white.Tornado seen here is front lit by the sunlight so appears whiteMost Tornadoes are photographed from the west so appear black or grey
13 Different types of Tornado Discontinuous funnel in the rainThis funnel made a sudden appearance from out of the rain.An example of what might lurk in a tornadic storm
14 Classification of |Tornadoes Done using the “Fujita Scale”F-0: mph, chimney damage, tree branches broken F-1: mph, mobile homes pushed off foundation or overturned F-2: mph, considerable damage, mobile homes demolished, trees uprooted F-3: mph, roofs and walls torn down, trains overturned, cars thrown F-4: mph, well-constructed walls leveled F-5: mph, homes lifted off foundation and carried considerable distances, autos thrown as far as 100 meters
15 HowTornadoesHideTornadoes hide in many ways -- under cover of darkness, heavy rain, landscape.They usually develop in areas in which a severe thunderstorm watch or warning is in effect. Remain alert to signs of an approaching tornado and seek shelter if threatening conditions exist
16 TornadoMythsMYTH: Areas near rivers, lakes, and mountains are safe from tornadoes.FACT: No place is safe from tornadoes. In the late 1980's, a tornado swept throughYellowstone National Park leaving a path of destruction up and down a10,000 ft. mountain.MYTH: The low pressure with a tornado causes buildings to "explode" as thetornado passes overhead.FACT: Violent winds and debris slamming into buildings cause most structuraldamage.MYTH: Windows should be opened before a tornado approaches to equalizepressure and minimize damage.FACT: Opening windows allows damaging winds to enter the structure. Leave thewindows alone; instead, immediately go to a safe place.
17 In a home or building, move to a pre-designated shelter, such as a basement. Stay away from windowsIf an underground shelter is not available, move to an interior room or hallway on the lowest floor and get under a sturdy piece of furniture.TornadoSafetyMobile homes, even if tied down, offer little protection from tornadoes and should be abandoned.Interior bathroom was all that was left standing of this house:
18 Tornado Safety at School Go to an inside hallway at the lowest level (central 1st floor hallway).Stay inside1st floor aisle side cubicles under work surfaceRooms (restrooms, etc. adjoining 1st floor aisleAvoid places with wide-span roofs areasMove away from exterior walls and windowsGet under a piece of sturdy furniture such as a cubicle work surface or heavy table or desk and hold on to it. (Several of the people that survived the Jarrell tornado lived because they had gotten into a bathtub).Use arms to protect head and neck.
19 Tornado Safety Get out of automobiles. Do not try to outrun a tornado in your car; instead, leave it immediately.
20 Vehicle Procedures During a Tornado Never try to out drive a tornado in a car or truck. Tornadoes can change direction quickly and can lift up a car or truck and toss it through the air.Get out of the car immediately and take shelter in a nearby building.If there is no time to get indoors, get out of the car and lie in a ditch or low-lying area away from the vehicle. Be aware of the potential for flooding.
21 Procedures for Outdoors If possible, get inside a building.If shelter is not available or there is no time to get indoors, lie in a ditch or low-lying area or crouch near a strong building.Be aware of the potential for flooding.Use arms to protect head and neck.
22 Before A Tornado Happens Conduct tornado drills each tornado season. Designate an area in the office as a shelter, and practice having everyone go there in response to a tornado threat.
23 Tornado Drill Procedures When the tornado alarm is given you must immediately:Always treat any alarm as the real thing.Take cover quicklyGo to the designated tornado shelter for your office.Avoid places with wide-span roofs such as auditoriums, cafeterias, large hallways, or shopping malls.Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.Use arms to protect head and neck.Safety personnel should monitor the process and fill out the evacuation report.
24 After the All Clear Is Given You must follow all procedures set forth in the emergency evacuation policy.Report to the designated meeting area for roll call.Remain calm, no smoking or talking.Follow the directions of safety personnel.Evacuation Meeting area.
25 Communications Is Key Element After the Tornado. Remember to follow the communications procedures set for your department. Staying in touch will help:Ease the concerns of family members.Formulate a response to the emergency with information supplied by you on the status of the system.
26 Destruction caused by Tornadoes Its troublesome when you’ve got no home to come home to.Schools out!Just as well there was no-one in this car!This church was never the same again
27 SummaryTornadoes are a serious problem causing widespread devastation.Quick thinking could save lives