What are the differences between a cyclone and an anticyclone?
- low vs high pressure
- ocean vs land
- counter-clockwise circulation vs clockwise in Northern hemisphere
- spring vs winter
How, where and under what conditions to extratropical cyclones form?
- form along weather fronts over land or ocean in mid-latitudes
- uses energy from contrasting temperatures of air masses
What are the hazards associated with extratropical cyclones?
- high waves
- coastal erosion
- wind damage
Where and how does a tropical cyclone form?
- from disorganized low pressure systems (troughs)
- over tropical ocean away from the equator
What are cyclones called in areas of the world?
- hurricanes - atlantic
- typhoons - everywhere else
What environmental conditions are needed for a hurricane to form/live?
warm water 80 degree F and 150 ft deep
What are the structures of a cyclone
- rain bands: spiraling lines of thunderstorms with some "towers" extending to top of troposphere
- eye: circular area of calm winds, lowest atmospheric pressure
- eyewall: most intense winds and rains, sometimes inner and outer eyewall
How is a tropical storm defined?
winds > 39 mph, low pressure area
How is a hurricane defined?
- winds > 74 mph
- 5 categories based on wind speed intensity
What are the stages in a life cycle of a tropical cyclone?
- tropical storm
What are the common tracks these storms follow in the Atlantic Ocean and what land areas are in danger?
- inter-tropical convergence zone (ITCZ) west of Africa in Atlantic
- tracks north out into Atlantic or West into Gulf of Mexico
- Haiti, Cuba, Florida, Louisiana, Carolinas
What are some hurricane hazards?
- storm surge
- massive erosion and deposition
- loss of infrastructure
What factors affect storm surge height?
- wind speed
- speed of storm
- profile of seaflore
- atmospheric pressure
- time of day
- barrier islands and wetlands to protect cities, followed by levees and floodwalls
What caused Hurricane Katrina to be so devastating and how could this have been avoided?
- damming of rivers lessened needed deposition for barrier islands and wetlands
- failure in levees and floodwalls
- failure in FEMA regarding communication and leadership
education and awareness of the hazard
What is importance of coastal wetlands?
1 mile of wetlands reduces storm surge by 1 foot
How can you mitigate for hurricane hazards?
- prep for flooding & high winds
- evacuate or take shelter
- prep for 3+ days without source of food, water, or power
- Engineering - elevated structures, etc.
- Insurance - not working well presently, becoming costly
- Zoning - don't build certain structures on a coast at risk
What should individuals do to prepare for a large hurricane
- survival/emergency kit
- flashlight, fire extinguisher, NOAA, cash, raingear, meds, water purification, maps
- concentrated winds at high altitudes (troposphere)
- polar and subtropical
closed circulation on tropical disturbance
winds > 39 mph
winds > 74 mph
inter-tropical convergence zone
- area encircling earth near equator where trade winds converge causing erratic weather patterns
- known to sailors as the doldrums
When is hurricane season in the US
July - November
abnormal rise in sea level along a coast, due to high winds in ocean literally pushing the water towards the coast
a lowland area that is saturated with moisture
federal emergency management agency