Lecture 19 Flashcards
Where are winds strongest within a hurricane?
Left side of hurricane
Build up of energy of radial and tangential (rotational) component of wind
Threats from hurricane
Strong wind, explosive pressure drops, seawater surges, flooding
Hurricane Sandy
22-29 October 2012 Almost 100 dead Major to record storm surge $50 billion in damage in US Category 3
Hurricane Juan
24-29 September 2003 8 deaths $113 million US$ Began as tropical depression about 480km southeast of Bermuda Category 2
Hurricane Katrina
1233 deaths
40-60 billions $ in damage, US
Hurricane Rita
33 death
4-7 billion $, US
Hurricane Irene
56 deaths
10.1 billion $, US
Hurricane prediction
Months in advance of the season (hurricane history, SST, ENSO (for longer term prediction), factors controlling tracks)
Attempt to estimate number and magnitude for a season, but cannot predict landfall location or time
Outlooks are issues throughout the year
SST
Surface skin temperature
Higher temperature, more likely to have hurricanes
ENSO
El Nino Southern Oscillation
Monitors sea-level pressure,
zonal and meridinal components of surface wind, sea surface temperature, surface air temperature, and total cloudiness fraction of the sky
ENSO
El Nino Southern Oscillation
Monitors sea-level pressure,
zonal and meridinal components of surface wind, sea surface temperature, surface air temperature, and total cloudiness fraction of the sky
Hurricanes are more frequent when…
El Nino absent
West Africa has wetter summer
Warner sea surface
Hurricanes are fewer when…
El Nino present
Cooler sea surface
West Africa has drier summer
Models for hurricane prediction
1) Atmospheric dynamics models
2) Statistical models
3) Dynamics-statistical model
4) Consensus model
Atmospheric dynamics model
Physics-based, supercomputer numerical models, track position and intensity