Hurricanes and Extratropical Cyclones

Cyclone

Area/center of low atmospheric pressure characterized by rotating winds

Tropical cyclones

Large thunderstorm complex rotating around an area of low-pressure

Form over warm tropical subtropical waters

Extratropical cyclones

Mid-latitude cyclones/wave cyclones

Associated with the development of weather fronts + possess cool cores

Saffir-Simpson Hurricane Scale of severity

 Rating of 1-5 based on hurricane’s present intensity

Storm Surge

Local rise of sea level resulting from water pushed toward shore by winds swirling around a storm

Heavy Rains

Occurs with storms of variable intensities + tropical storms and even tropical depressions can cause extensive flooding

Factors of Heavy Rain

Storm’s speed, changes in land elevation, interactions with other storms, amount of water already present, drainage pattern can route flooding water back into already damaged coastal areas

Trends affecting hazards exposure to cyclones?

Coastal erosion being rapidly increased as a result of the storms

Saltwater flooding with storm surge

Freshwater flooding from rainfall

Landslide

Downbursts of precipitation-driven winds and tornadoes

Sea level rises

How to minimize?

Accurate forecast

Issue timely advisories to warn populations

Evacuate people from harm's way

Mandate improved building codes and strategically plan how to make use of coastal resources

Examples of equipment used for forecast and need for hurricane hunters still today:

Weather satellites

Hurricane-hunter aircraft

Doppler radar

Weather buoys

Ship reports

Computer models

Hurricane watch

 Issued when storm is likely to make landfall within the next 36 hours

Hurricane warning

Issued when the storm is likely to make landfall within the next 24 hours or less

Coriolis

Apparent deflection that occurs as a result of the rotation of a body (earth)

Cyclogenesis

Initial frontal formation typically occurs off the west coast

Tropical depression

When winds increase and begin to spiral, forming a low-pressure center

Characteristic of Hurricane Katrina

Ranked top 5 of intense hurricanes to make landfall in the U.S.

Barometric pressure of 902

Human catastrophe