Hurricanes And Tornadoes Flashcards
How hurricanes form
1.Dry hot air on surface of ocean rapidly heat and evaporate = low pressure and instability
2. Condensation around hygroscopic nuclei = latent heat, increase instability = tall thick cumulonimbus clouds
3. wind reach 23-39mph cuz low air pressure, cloud replaces evaporated warm air = thunderstorm
4.Thunderstorm creates humid surrounding air = supply storm with more latent heat transfer energy
5.Coriolic forces moves wind in a circular motion
6.Winds in upper atmosphere weaken with height = air spirals outwards or sink into eye, creates a hurricane when winds over 74
1. dry hot air on surface of ocean = heated evaporates and = low pressure
2. condensation around hydroscopic nuclei = released latent heat = increase instability = cumulonimbus cloud
3. surface winds as cold air replaces the warm air = thunderstorm = increase latent heat
4. Coriolis force moves strong winds in a circular pattern = increase speed towards the centre = tropical storm
5. winds in upper atm. Weaken and spiral outwards = tropic cyclone
6. whole system moves westward and route varies over the ocean
- dry hot air on surface of ocean = heated evaporates and = low pressure
- condensation around hydroscopic nuclei = released latent heat = increase instability = cumulonimbus cloud
- surface winds as cold air replaces the warm air = thunderstorm = increase latent heat
- Coriolis force moves strong winds in a circular pattern = increase speed towards the centre = tropical storm
- winds in upper atm. Weaken and spiral outwards = tropic cyclone
- whole system moves westward and route varies over the ocean
Primary impact from hurricanes
Storm surges
Coastal flooding
River flooding
Strong winds
Mass movements
Heavy rainfall
Typhoon/Hurricane Haiyan in the Philippines key facts
195mph
895 air pressure
90% flooded
6300 deaths (5,800 from storm surge)
5 million homeless
$8 billion in cost
Occurred 2013, 7 Nov
Management of Hurricane Haiyan
Prediction - satellite and computer models
Prepare - afforestation, warning systems
Response - Red cross, UN raises 788 million, slow overall response 100 police reported for duty
Factors of Hurricanes
1.Last 1-2 weeks usually
2.Wide and thick (500-800km wide)
3.Circular funnel with columns of clouds shaped
4.74mph+
5. High Air pressure around 910-980
6. June-Nov occurs in NA
Factors for Tornadoes
- Short duration (minutes-hours)
- Thin 80m (but can reach 2miles)
- Cone vortex funnel shape
- Low air pressure
- Fast 75-100mph (but can reach 300mph)
- Occurs spring/early summer in NA
What direction do Hurricane spin
Counterclockwise in Northern Hemisphere, Clockwise in Southern Hemisphere
Formation of Tornadoes
- Cold and Warm front meets
- Fronts collide causing frontal rainfall
- Creates cumulonimbus clouds and an anvil head due to jet streams
- Instability = thunderstorms = supercell
- Wind shear and jet streams = increase speed and increase narrowness = horizontal spinning = mesocyclone
- Column of cold air sinks = rain and increase flooding
- Difference in warm inflow and cold outflow = drag
Important information from Tornado in Oklahoma
Occurred 2013, 20 May
3 schools, 1 hospital, 1 theatre destroyed
24 killed
2 billion in cost
10,000 affected
fires, power outages
2500 homes destroyed
Management of Tornado in Oklahoma
Predict - Hazard mapping, ballons, 290,000 storm spotters, rada, satellite
Prepare - Education, reinforced underground shelters, Oklahoma department of emergency protocols
Response - assistance from US gov, doctors and nurses, FEMA, Mandatory building code withstand EF-2
Hazards of Tornadoes
Torrential rainfall
Hail storms
High winds
Impacts of Tornadoes
Lifting vehicles
Uprooting trees
Destroy Buildings
Hurl lethal missiles (cows)
Winds blast over roof, roof blow away
Secondary impacts:
Poverty
Homelessness
Anxiety
Loss of life
