Natural hazards final Hurricanes
How a hurricane works/develops
-Becomes tropical depression (receives identifying number) -Surface winds strengthen and flow around and into core -Rotates counterclockwise (in northern hemisphere)
typhoons and cyclones
-Mostly form on west sides of oceans where warm water is concentrated -The east-west width of the tropical ocean, and the distribution of warm water currents at mid latitudes exert strong spatial controls of the birth and development of hurricanes
Requirements for development of hurricane (4)
1) Seawater at least 27oC (80oF) in upper 60 m 2) Air must be warm, humid and unstable 3) Weak upper-level winds, preferably blowing in same direction as developing storm is moving 4) Coriolis effect must be significant
1,836
100,000 Peopledid not evacuate:_____ of them died
present
1995-_____ has had Numerous seasons with many hurricanes
Hurricane Katrina
24 Aug 2005, New OrleansThe costliest hurricane in US history, with the third highest death toll. -80% of New Orleans was flooded
3 to 5
As it approached New Orleans, Hurricane Katrina grew in strength from a category __ to a category __ hurricane overnight.
84
Average of ___ tropical cyclones (hurricanes, typhoons, cyclones) form each year.
Inside eye of hurricane
Cool, high-altitude air sinks and absorbs moisture
Katrina, $160 Billion
Costliest mainland US tropical cyclones, 1900-2017, corrected for inflation to 2017 dollars. Most costly was hurricane _______ with $________ in damage.
eye wall of hurricane
Cylinder-shaped area of spiraling upward winds around eye Strongest winds
Gavelston, Texas 1900 (Sep 8th)
Deadliest hurricane in the U.S. which resulted in 8,000 deaths?
winds, storm surges, heavy rains/inland flooding(59%)
Destruction and deaths caused mainly by (3 things)
Predicting hurricane season forecast
Difficult, but increased number of storms in North Atlantic region can be forecast based on: -Wetter western Sahel region, Warmer sea surface temperatures, Low atmospheric pressure in Caribbean, La Nina conditions in Pacific
25
FEMA estimates in next 60 years: ___% houses within 150 m of shorelinewill fall into water during some hurricane, without mitigating actions
Geography, urban development, subsidence, warm sea surface temp
Factors that contributed to Hurricane Harvey flooding (4)
240
Generate winds over _______ km/hr
latent heat
Huge amounts of _____ ______ released by water vapor as air rises -much more than kinetic energy of the winds. (how hurricanes work)
51.88
Hurricane Harvey dropped ______ inches of rainfall on Houston.
Mitch
Hurricane _____ (October 1998)On 26 October -became one of the strongest category 5 hurricanes ever observed, with 180 mph winds
deaths, damages
Hurricane _____ are down in recent decades however, Hurricane ______ are up -Larger, more expensive homes on coastlines. (north Atlantic ocean hurricanes)
Ike
Hurricane _____ in 2008 (Category 2) -Wind damage and flooding extends far inland (affected Ohio, Michigan)
Harvey
Hurricane ______ (August-september 2017) the second costliest Hurricane on record (after Katrina), inflicting damage primarily from catastrophic rainfall-triggered flooding in the Houston metropolitan area. - the wettest tropical cyclone on record in the United States.
Andrew (1992)
Hurricane ______ was forth most costly hurricane in US history (after Katrina, Harvey and Irma ). This hurricane did enormous damage in Florida. -It was wind rather than water that did most of the damage during this event.
Bangladesh and Burma
Hurricane death toll record is the worst in which countries? In 1970 a single cyclone in ________ killed ~ 400,000 people. The death toll in the 2008 _______ cyclone exceeded 100,000 people.
zone c
If located to South: guides hurricanes to Gulf of Mexico
zone a
If small, or located to the north: hurricanes miss coastlines
zone b
If strong, extensive: guides hurricanes along east coast of U.S.
Hurricanes
Large tropical ocean storms powered by the latent heat of water vapor. -They provide one mechanism for transferring heat from lower to higher latitudes -Heat engines converting heat of tropical ocean into winds, waves
sun
Location of ITCZ (Intertropical Convergence Zone ) moves with migration of the ____. -associated with tropical storm/hurricane Mitch 1998
Azores
Many north Atlantic ocean hurricanes develop in Atlantic in the vicinity of the _______. Tropical disturbances form as the result of instabilities in the trade winds.
late summer
Most hurricanes form in _____ _______-this time period is that in which tropical and sub-tropical waters have reached their maximum temperatures.
2005
Numerous records made during the ____ Atlantic hurricane season
building codes, roofs, Reduce Impact of Wind borne Debris, Land Use Planning
Reduction of hurricane damage improvements
Bangladesh
Seven of world's nine most deadly weather events in 20th century were cyclones hitting densely populated ________.
Florida (113)
State with most hurricane landfalls on US coast line?
119 km/hr (74 mph)
Surface wind speed (general characteristics of north Atlantic hurricane)
Gavelston
The ________ Hurricane -September 1900. The drowning of an entire city. -city destroyed by category 4 hurricane -More than 6000 people drowned
Nargis, Burma
The ruling military refused international aid with cyclone _____ in _____ in 2008. 80,000 fatalities occurred.
200x
The total power production associated with an average hurricane is ______ times that of global electrical power production.
119
When winds exceed ____ km/hr its a hurricane
63
When winds exceed _____ km/hr its a tropical storm
storm surge
Winds push water ashore to pile up above normal levels, especially on right-hand side of storm -where wind velocities are highest.
North Atlantic Oscillation
_____ ______ _______ (NAO) appears to correlate with Hurricane activity.
2017
______ was a memorable Atlantic Hurricane season, but did not surpass 2005
Size, position of Bermuda (Azores), North Atlantic high pressure zone
what influences hurricane paths?
