Comparing Hurricanes and Hurricane Seasons Saffir-Simpson Scale What is a hurricane? What 4 conditions are necessary for hurricane formation What happens as hurricanes approach land? Based on wind speed: Hurricanes that are Category 3 or
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Presentation Transcript
01
Comparing Hurricanes and Hurricane Seasons<br>
02
Saffir-Simpson Scale What is a hurricane?
What 4 conditions are necessary for hurricane formation
What happens as hurricanes approach land? Based on wind speed: Hurricanes that are Category 3 or higher (>111 knots) are called major hurricanes.<br>
03
ACE =10-4Σ(maximum wind speed in knots)2
maximum sustained winds every 6 hours Accumulated Cyclone Energy<br>
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Example: Irene (2011)<br>
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Example: 2011 Total Is a seasonal total ACE of 126 above normal? Below normal? Normal?<br>
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ACE Season Totals What was last season’s ACE total?
http://www.srh.noaa.gov/bro/?n=2012event_hurricaneseasonwrap<br>
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Seasonal Outlooks There is great interest in trying to predict:
How many hurricanes, major hurricanes?
WHY?
General awareness/preparedness
Some predictions about climate are useful for deciding what crops to plant
HOWEVER — we cannot yet predict specific hurricanes more than a few days in advance<br>
08
We are currently in a high-activity era More total storms per year
More big storms per year
And more energy released by all the hurricanes combined in a year (ACE)<br>
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The latest . . .<br>
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Looking at the most recent hurricane season outlook for the Atlantic Ocean: http://www.cpc.ncep.noaa.gov/products/outlooks/
What implications can you imagine for this outlook (above-normal, normal, or below-normal) for
a farmer in Georgia?
a governor in New Jersey?
your own life? Plant more drought-resistant or water-loving crops?
Allocate funds for education and evacuation?
Cut tree limbs near house? Restock emergency kit?<br>
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Summary How big is a hurricane?
Saffir-Simpson scale
ACE Index calculation
Multi-decadal cycles (high/low activity eras)
Seasonal outlooks and applications to society<br>
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References and Reuse Slide 4. Data in public domain.
http://en.wikipedia.org/wiki/2011_Atlantic_hurricane_season
Slides 4 and 5. Data in public domain . . . Can be updated for different years and hurricanes:
http://rammb.cira.colostate.edu/products/tc_realtime/
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Screenshot from NOAA. Website in public domain.
http://www.srh.noaa.gov/bro/?n=2012event_hurricaneseasonwrap
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Screenshot from NOAA. Website in public domain.
http://www.cpc.ncep.noaa.gov/products/outlooks/hurricane2012/August/figure3.gif
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Screenshot from NOAA. Website in public domain.
http://www.cpc.ncep.noaa.gov/products/outlooks/figure2.gif
Slide 11. Screenshot from NOAA. Website in public domain.
http://www.nhc.noaa.gov/
Slide 12 refers to Hurricane Outlooks at:
http://www.cpc.ncep.noaa.gov/products/outlooks/<br>
