SCIENCE NEWS Thunderstorms What are thunderstorms? A storm which contains A storm which contains...
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Transcript of SCIENCE NEWS Thunderstorms What are thunderstorms? A storm which contains A storm which contains...
SCIENCE NEWSSCIENCE NEWS
Thunderstorms
What are thunderstorms?What are thunderstorms?
A storm which containsA storm which contains
lightning and thunder lightning and thunder
Why Study Thunderstorms ?Why Study Thunderstorms ?
FatalitiesFatalities InjuriesInjuries
Property Damage Property Damage Crop DamageCrop Damage
Weather related deaths in the Weather related deaths in the u.s.u.s.
Weather damage costWeather damage cost in the U.S. in the U.S.
According to NOAA’s National According to NOAA’s National Weather ServiceWeather Service
The US has sustained 90 The US has sustained 90 weather related disasters over weather related disasters over the 29 years the 29 years
Total cost of all 90 events?Total cost of all 90 events?
$700 billion$700 billion
ILLINOIS ILLINOIS According to NOAA, 2008 Summary According to NOAA, 2008 Summary
of Hazardous Weather Fatalities, of Hazardous Weather Fatalities, Injuries, and Damage Costs by Injuries, and Damage Costs by
StateState Fatalities 35 Fatalities 35 Injuries 48 Injuries 48 Property Damage $ 227.14 millionProperty Damage $ 227.14 million Crop Damage $ 41.04 millionCrop Damage $ 41.04 million Total - $ 268.18 millionTotal - $ 268.18 million
Average number of days perAverage number of days peryear with thunderstormsyear with thunderstorms
FACTSFACTS
FEATURESFEATURES Cumulonimbus Cumulonimbus
cloudsclouds Heavy rainfallHeavy rainfall LightningLightning Occasional hailOccasional hail
OCCURANCESOCCURANCES 2000 in progress 2000 in progress
at any one timeat any one time 100,000 per year 100,000 per year
in the United in the United StatesStates
Most frequent in Most frequent in Florida and Florida and eastern Gulf eastern Gulf Coast regionCoast region
All thunderstorms needAll thunderstorms needMoisture Moisture -- source typically over source typically over water, cloud formation & rainwater, cloud formation & rain
LiftingLifting- - mechanism for condensing mechanism for condensing moisture to release its latent heatmoisture to release its latent heat
Unstable air-Unstable air- rising air warmer rising air warmer than the surrounding air, produce than the surrounding air, produce
upward growing clouds and upward growing clouds and vertical updrafts keep precipitation vertical updrafts keep precipitation
suspendedsuspended
2 Types of Thunderstorms2 Types of Thunderstorms
Classified by lifting mechanismClassified by lifting mechanism
1. Air mass1. Air mass - unequal heating of - unequal heating of surfacesurface
MountainMountain : Orographic lifting : Orographic lifting
Sea breezeSea breeze : difference between : difference between land/water storage & release of land/water storage & release of thermal energy thermal energy
2. Frontal2. Frontal – advancing cold fronts and – advancing cold fronts and
more rarely warm frontmore rarely warm front
Stages of developmentStages of development
3 distinct stages make up a t-3 distinct stages make up a t-stormstorm
Cumulus stageCumulus stage
Warm, humid air rises vertically and Warm, humid air rises vertically and condenses into a cumulus cloud condenses into a cumulus cloud
Large amounts of latent heat are Large amounts of latent heat are release inside the cloudrelease inside the cloud
As the cloud grows, particles As the cloud grows, particles eventually get heavy enough toeventually get heavy enough to
fall also sides of the cloud evaporates fall also sides of the cloud evaporates forming a downdraftforming a downdraft
No precipitation during this stageNo precipitation during this stage
Cumulus StageCumulus Stage
Mature stageMature stage
The appearance of a downdraft The appearance of a downdraft Updraft/downdraft is called a Updraft/downdraft is called a
““cellcell”” An “anvil” top appears as the An “anvil” top appears as the
updrafts hit the tropopauseupdrafts hit the tropopause Heavy rain possible in this stageHeavy rain possible in this stage Strong/gusty surface windsStrong/gusty surface winds
Mature StageMature Stage
DissipationDissipation
Downdrafts basically choke out Downdrafts basically choke out the updraftsthe updrafts
Cuts off the warm, moist air Cuts off the warm, moist air which is the energy supply for which is the energy supply for the stormthe storm
Light rain onlyLight rain only
Dissipating StageDissipating Stage
Multi cell thunderstormsMulti cell thunderstorms
If new thunderstorms forms If new thunderstorms forms due to downdrafts from the air due to downdrafts from the air mass, they are called “mass, they are called “multi multi cellcell” thunderstorms” thunderstorms
Most severe storms & ordinary Most severe storms & ordinary storms are multi cell storms storms are multi cell storms
Multi cell ThunderstormMulti cell Thunderstorm
Thunderstorm hazardsThunderstorm hazards Hail Hail
Collision of super Collision of super cool water drops cool water drops forms layersforms layers
Cause extensive & Cause extensive & quick damage quick damage
Largest Aurora, Largest Aurora, Nebraska 6/03 Nebraska 6/03
7 in diameter & 7 in diameter & 18.75 in 18.75 in circumference circumference almost a soccer ballalmost a soccer ball
Lightning & ThunderLightning & ThunderCharge differences Charge differences between the between the thunderstorm and thunderstorm and ground can cause ground can cause lightning strokes lightning strokes of 30,000°C, and of 30,000°C, and this rapid heating this rapid heating of air will creates of air will creates an explosive shock an explosive shock wave called wave called thunder, which thunder, which requires requires approximately 3 approximately 3 seconds to travel 1 seconds to travel 1 kilometerkilometer
Lightning Stroke DevelopmentLightning Stroke Development
Charge layers in the cloud Charge layers in the cloud are formed by the transfer are formed by the transfer of positive ions from of positive ions from warmer hailstones to warmer hailstones to colder ice crystals.colder ice crystals.
When the negative charge When the negative charge near the bottom of the near the bottom of the cloud is large enough to cloud is large enough to overcome the air's overcome the air's resistance, a stepped resistance, a stepped leader forms.leader forms.
A region of positive ions A region of positive ions move from the ground move from the ground toward this charge, which toward this charge, which then forms a return stroke then forms a return stroke into the cloud.into the cloud.
Lighting Lighting
• Several names, such as Several names, such as forked, bead, ball, and sheet forked, bead, ball, and sheet lightning describe forms of the lightning describe forms of the flashflash
• Distant, unseen lightning is Distant, unseen lightning is often called heat lightningoften called heat lightning
2007 Lightning Fatalities2007 Lightning Fatalities 45 lightning fatalities45 lightning fatalities Above the 10-year average of Above the 10-year average of
44 fatalities.44 fatalities. For the 9th consecutive year, For the 9th consecutive year,
Florida was hardest hit with 11 Florida was hardest hit with 11 fatalitiesfatalities
Illinois 1 fatalityIllinois 1 fatality
ANY QUESTIONS?
HOMEWORKHOMEWORK QUIZ? QUIZ?
Read Ch 13 p 344- 349Read Ch 13 p 344- 349
Ch 13 Study Guide Due Tues 4/28 Ch 13 Study Guide Due Tues 4/28
Ch 12 test corrections due TR Ch 12 test corrections due TR 4/304/30
Good ReferencesGood Referenceshttp://www.eoearth.org/article/Thunderstormhttp://www.eoearth.org/article/Thunderstorm
USE THIS FOR SEVERVE TSTROMSUSE THIS FOR SEVERVE TSTROMS
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