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Causes of hurricanes and storms in u.s.a


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Causes of hurricanes and storms in u.s.a

  1. 1. GEOGRAPHICAL LOCATION OF U.S.A  U.S.A. is comprised of 52 states which are surrounded by the Atlantic and Pacific ocean and the Gulf of Mexico.  Lower 50 states have Atlantic Ocean on the East ,Pacific Ocean on the West and Canada is in the North of America .
  2. 2.  Mexico is in the South while The Gulf of Mexico is in the Southeast of U.S.A. • Alaska has the Arctic Ocean on the north and Pacific Ocean on the south. • Hawaii is the chain of islands surrounded by Pacific Ocean.
  3. 3.  STATES THAT BORDER ATLANTIC OCEAN: New York , North Carolina, South Carolina, Georgia, Florida , Maryland, Virginia, New Jersey  STATES THAT BORDER THE PACIFIC OCEAN: Alaska, California, Hawaii, Oregon, Washington  STATES THAT BORDER THE GULF OF MEXICO: The Gulf of Mexico has total area of 1.5 million sq. km.  Alabama ,Florida , Louisiana ,Mississippi and Texas
  4. 4. STORM DEFINATION:  A disturbance of the normal condition of the atmosphere, marked by winds of unusual force or direction, along with heavy rain, snow, hail, thunder, and lightning, or flying sand or dust.
  5. 5. SEVERE WEATHER:  “Natural Disasters And Severe Weather” , The National Weather Service defines severe weather as:  Tornadoes  Hail of greater than 1 inches in diameter • Winds of speed greater than 55 mph  Knox Pam ,2011:Natural Disaster:What Causes Severe Weather. reived at 4 May 2013
  6. 6. CAUSES FOR EXTREME WEATHER IN U.S.A  The central plains  Other countries are shielded  Size of the U.S  Ocean front property  Ocean currents
  7. 7. COMMON TYPES OF STORMS IN U.S.A  Winter storms  Floods  Hail storms  Tornadoes  Derecho storms  Tropical cyclones (Hurricanes)
  8. 8. WINTER STORMS  Winter storms derive their energy from the clash of two air masses of different temperatures and moisture levels. • Winter storms usually form when an air mass of cold, dry, Canadian air moves south and interacts with a warm, moist air mass moving north from the Gulf of Mexico.
  9. 9. TYPES OF WINTER STORMS  Ice storms  Blizzard  Lake Effect snow  Nor'easters
  10. 10. ICE STORMS  An ice storm is a type of winter storm caused by freezing rain.  The U.S. National Weather Services defines an ice storm as a storm which can accumulate at least 0.25 inches of ice on exposed surfaces.
  11. 11. BLIZZARDS  Blizzards are accompanied by gusty winds  Accumulating snow at a rate of 5 cm per hr.  Temp. -10 ͦC and wind speed greater than 35mph
  12. 12. LAKE EFFECT SNOW  Winds accompanying Arctic air masses generally blow from a west or northwest direction, causing lake effect snow to fall on the east or southeast sides of the lakes.
  13. 13. NOR'EASTERS  They are strong areas of low pressure that often form either in the Gulf of Mexico or off the East Coast in the Atlantic Ocean.  Nor'easters are notorious for producing heavy snow, rain, and oversized waves that crash onto Atlantic beaches, often causing beach erosion and structural damage.
  14. 14. According to a research paper, “Monitoring and understanding trends in extreme storms”, The dominant factors that determine US winter storms characteristics ( frequency, duration and intensity) are El Nino and La Nina .La Nina favors northerly storms bringing intense snow to Northern Midwest and the northern Rockies, while El Nino favors southern storms bringing heavy precipitation to southern states. • Kunkel, Kenneth E., and Coauthors, 2013: Monitoring and Understanding Trends in Extreme Storms: State of Knowledge. Bull. Amer. Meteor. Soc., 94, 499–514. doi: x.dRetrieved at 4 May 2013
  15. 15. Tornado is a violent ,low pressure storm relatively small in diameter. Tornados are most common in united states than any other country. United states receives 1200 tornado annually . Tornados in united states can occur at any time but they are more common in spring .
  16. 16. IMPACTS  United states receives many deaths and injuries related with tornados.  According to National Oceanic Atmospheric Administration (NOAA) most of deaths occur because people are not following guidelines.  Florida was the state with most losses.
  17. 17. TROPICAL CYCLONES  Low pressure structures that form over warm tropical waters and have gale force winds near the centre.  Heavy rainfall connected with the passage of a tropical cyclone can create extensive flooding.  tropical cyclones are important features of the Earth's atmosphere, as they transfer heat and energy between the equator and the cooler regions nearer the poles.
  18. 18. HOW DO TROPICAL CYCLONES FORM  Within region of low pressure air is heated over warm tropical ocean.  This air rises in distinct parcels causing thundery showers to form.  These showers come and go they grouped together in to large masses of thunder storms.  This create flow of very warm, moist air leading to increase of center of low pressure.
  19. 19. NOTABLE TROPICAL CYCLONES  Katrina - 2005 - Katrina was the most costly hurricane on record causing an estimated $75 billion in damage in Louisiana and Mississippi.  Andrew - 1992 - Andrew was a Category 5 hurricane which hit south-east Florida and south-east Louisiana causing $44,878 million of damage.  The most deadly tropical cyclone ever recorded hit Bangladesh in 1970 killing approximately 300,000 people.
  20. 20. IS CLIMATE CHANGE AFFECTING TROPICAL CYCLONES?  Climate models show that there may be an increase in tropical cyclone intensity in the future, under nonstop global warming.  However, the models also indicate that tropical cyclone rate will either remain unmoved or decrease.
  21. 21. THUNDERSTORMS  A thunderstorm is a kind of storm that generates lightning and thunder. It is usually accompanied by heavy precipitation  Thunderstorms can create many types of damage weather such as lightning, hail, tornadoes, straight-line winds, flooding and more.
  22. 22. HAIL STORMS  Hailstorms are defined as thunder storm that make hail.  Hail is defined as an opening at diameter of 0.2 inches or more.
  23. 23. DERECHO STORMS  A derecho is a huge, violent, fast-moving, complex of thunderstorms that chase one another along a course of at least 240 miles, with wind gusts of at slightest 58 mph.
  24. 24. HURRICANES  A hurricane is a tropical cyclone with winds that have speed of 74 miles per hour  Hurricanes in Atlantic ocean  Typhoons in Northwest Pacific ocean  Cyclones in South Pacific and Indian ocean
  25. 25. FORMATION CONDITIONS  Warm moist air  Warm water  High temperature (26.5 degrees C or above )  Humidity  Winds (Hurricane Formation - NOAA - National Oceanic and Atmospheric Administration)
  26. 26. STRUCTRE OF HURRICANES EYE  Center portion of hurricane  Low pressure place in hurricane  The eye is typically 20 to 40 miles  Does not forms until winds have speed of 74 mph EYE
  27. 27. EYE WALL  Eye wall surrounds the eye of hurricane  Strongest winds and heaviest rains are found  Its Contraction and expansion changes size  Challenges in forecasting the strength of hurricane EYE WALL
  28. 28. RAIN BANDS  Long curving bands of clouds that spiral around eye wall  Heavy rain and wind are associated with rain bands  Speed of winds within the rain bands decreases outward  Gaps between rain bands are calm having no wind or rain RAIN BANDS
  29. 29. SAFFIR-SIMPSON HURRICANE WIND SCALE  Estimates potential property damage.  1 to 5 rating based on a hurricane's sustained wind speed  Category 3 and higher are considered major hurricanes
  30. 30. Category Sustained winds Types of damages due to hurricane wind 1 74-95 mph 119-153 km/h Very dangerous wind will produce some damage 2 96-110 mph 154-177 km/h Extremely dangerous winds will cause extensive damage 3 (Major) 111-129 mph 178-208 km/h Devastating damage will occur 4 (Major) 130-156 mph 209-251 km/h Catastrophic damage will occur 5 (Major) 157 mph or higher 252 km/h or higher Catastrophic damage will occur
  31. 31. CAUSES OF KATRINAAND SANDY  Katrina was a tropical cyclone drew its energy from warm waters of Atlantic Ocean.  Sandy also blow through tropics but as the storm moved northward, it merged with a weather system arriving from the west and started transitioning into an extra tropical cyclone.
  32. 32. Difference between katrina and sandy Katrina Sandy Tropical cyclone drew their energy from warm ocean waters Extra tropical cyclones are fueled by sharp temperature contrasts between masses of warm cool air Symmetrical Asymmetric 65 km/h or 500 kilometer (300 miles) 1,500 kilometer (900 miles) Wind were more intensity but cover less area Cover more area
  33. 33. NAMING OF HURRICANES  List of hurricane names for 2013  Andrea, Barry, Chantal, Dorian, Erin, Fernand, Gabrielle, Humberto, Ingrid, Jerry, Karen, Lorenzo
  34. 34. For formation Hurricanes need Heat Moisture It generally form on tropical ocean where these two condition exist.
  35. 35.  Human activities increase the global warming which lead to increase in 1. Air 2. water temperature over the globe. Variation in temperature in Atlantic increase the severity of hurricanes over the pervious years
  36. 36. FREQUENCY AND SEVERITY OF HURRICANES INCREASES The three main factor of temperature change causes hurricanes 1)Rise in temperature of air and water over the globe. 2)Human activities like deforestation and greenhouse gases. 3)Failure to take action now to lower atmospheric level of greenhouse gases will responsible for frequent and sever hurricanes in coming years.
  37. 37. RESEACH REPORT The scientist of Princeton University and the Massachusetts institute of technology provides the indication of In coming years the extreme hurricane strike the united state and coastal area because of variation in temperature. According to statement of professor Michael Oppenheimer “sea level rise and warmer water temperature could possibly cause a storm that likes of which have not been seen”
  38. 38. Scientist believe that rise of sea level by 2100, cause a hurricane of century which have not been seen before. Research evidence shows that increase in temperature cause a rise of storm surge. NASA reported that there is increase in temperature of 1 Fahrenheit over the past 100 years on tropical ocean surface.
  39. 39. Green house gases are major contributor increase in temperature of sea which cause hurricanes. That there is strong relationship between the tropical Atlantic sea surface temperature and Atlantic hurricanes activities. The rain fall and wind speed also increase by human activities i.e.1oc increase in tropical sea surface temperature: hurricanes surface wind speeds increase =1 to 8% increase rainfall rates =6 to 18%.
  40. 40. Hurricanes in Atlantic ocean Atlantic hurricanes start from the west coast of Africa and move west toward United States. Hurricanes of Atlantic rise in late summer and earlier autumns.
  41. 41. Difference in East and West coast of USA Atlantic Ocean hurricanes form which cover the 1)East side of U.S. 2)Northeast pacific basin to the west of the U.S.
  42. 42. Reasons 1) The hurricanes form in the tropical and subtropical latitude when they move toward the west-northwest. In the Atlantic the hurricanes strike to the U.S east coast area because of motion. 2) the major factor which is involve is the temperature difference in east and west coasts of U.S. The east coast provide the source of warm water (>80of or 26.5oc)
  43. 43. The formation of hurricanes is also affected because of ocean clockwise current. The current move from north to south in the pacific, whereas on the east coast the warm water move from south to north from the Gulf flows
  44. 44. REFRENCES • Atlantic Ocean and USA. hurw.htm.Retrieved at 4 May 2013. • Causes of Katrina and Sandy. 2012_Sandy.html.Retrived at 3 May 2013. • Climate Change Cause Hurricanes; U.S.A NEWS. change-could-cause-killer-hurricanes-in-nyc. Retrieved at 4 may 2013.
  45. 45.  Deadly Storms in U.S.A. news/deadly-super-derecho-strikes- m/67383.Retrived at 3 May 2013  Five Factors Contribute To Increased Severe Weather in U.S.A. eved at 29 April 2013  Geographical Location of U.S.A. at 30 April 2013.  Geography Of Gulf Of Mexico m.Retrieved at 1May 2013  Hurricanes in east and west coast of USA at 4 May 2013.
  46. 46.  Hurricanes Basics. etrived at 2 May 2013  Hurricanes Formation. 4/stories/what-are-hurricanes-k4.html.Retrived at 3 May 2013  Ice storm and Lake Effect Snow. storms.htm.Retrieved at 2 May 2013  Knox Pam, 2011: Natural Disaster: What Causes Severe Weather. er.pdf.Retrieved at 4 May 2013  Kunkel, Kenneth E., and Coauthors, 2013: Monitoring and Understanding Trends in Extreme Storms: State of Knowledge. Bull. Amer. Meteor. Soc., 94, 499–514. D-11-00262.1 Retrieved at 4 May 2013.
  47. 47.  Naming of Hurricanes. at 3 May 2013.  SAFFIR-SIMPSON Hurricane Scale. at 3 May 2013.  Storm Definition. at 29 April 2013  Structure of Hurricanes. php. Retrieved at 2 May 2013.  The Hurricane Research Division (HRD) is a part of the Atlantic Oceanographic and Meteorological Laboratory (AOML). Retrieved at 4 May 2013.
  48. 48.  Tornadoes and Tropical cyclone formation in U.S.A cyclone/247926/Tornadoes.Retrieved at 2May 2013  U.S.A States That Surround Atlantic Ocean Retrieved at 30 April 2013  Winter storms. at 1May 2013