Hurricane Intensity

• Saffir-Simpson scale


  Scale used to identify the intensity of a hurricane based on wind speed
• Hurricane categories


  • Category 1
  • Category 2
  • Category 3
  • Category 4
  • Category 5
• Category 1


  • Sustained winds 74-95 mph
• Category 2


  • Sustained winds 96-110 mph (maximum strength of Hurricane Sandy in 2012)
• Category 3


  • Sustained winds 111-129 mph (Katrina's strength in 2005)
• Category 4


  • Sustained winds 130-156 mph (Florence and Michael in 2018)
• Category 5


  • Sustained winds 157+ mph (Andrew 1992, Maria 2017, Dorian 2019)
• Most hurricanes that have made landfall in the US since 1900 have been Category 1-3
• Flooding


  Major cause of life loss from hurricanes
• Storm surge


  Abnormal rise of several meters in ocean level that submerges low-lying coastal areas
• Causes of storm surge

  1. Wind driven surge

  2. Pressure driven surge

  3. General motion of the storm

  4. High tide
• A 17-foot storm tide with a 2-foot normal high tide would mean 15 feet of devastating surge
• Hurricane Andrew made landfall in Florida as a Category 5


  August 1992
• Andrew had maximum sustained winds of 175 mph and a pressure just above 27 inches
• Most active Atlantic hurricane season on record

  2005
• Hurricane Katrina made landfall in Mississippi and Louisiana as a Category 3


  2005
• Katrina was the costliest hurricane in US history with over $100 billion in damage</b>
• Hurricane Sandy made landfall in New Jersey as a Category 1


  October 2012
• Sandy caused devastating flooding and damage in New York and New Jersey
• Second most active Atlantic hurricane season on record

  2017
• Hurricane Florence made landfall in North Carolina as a weaker hurricane but caused massive flooding


  2018
• Hurricane Michael made landfall in the Florida Panhandle as the strongest hurricane to hit that area


  October 2018
• Michael had sustained winds up to 155 mph
• Hurricane Dorian was a Category 5 with 185 mph winds, the strongest since Andrew


  September 2019
• Dorian just grazed the Florida coast and did not cause the expected massive damage