Bellringer How might large bodies of water influence climate? What is transpiration? What are 2 of the 3 primary greenhouse gases?

Severe Weather Thunderstorms, Tornadoes, Hurricanes, etc…

Thunderstorms Most often associated with a Cumulonimbus Cloud Cold fronts often create this condition Produces UNSTABLE environment

Thunderstorm Formation Thunderstorms have three stages… The Cumulous Stage: Warm air rising and condensing to form clouds The Mature Stage: Strong updraft of warm, moist air, AND a strong downdraft of wind and precipitation (hail and lightning can occur in this stage too) The Dissipation Stage: Surface has cooled, cutting off the warm, moist air that “fuels” the storm

Lightning Created by friction between the rising updraft and the falling downdraft in a cumulonimbus cloud Creates a separation of charges Eventually discharge “spark” “spark” is a bolt of lightning

Thunder Lightning strikes, the “bolt” can be as hot as 30,000 degrees Air surrounding that bolt expands rapidly and then contracts quickly as it cools. air expands and contracts rapidly enough to break the sound barrier (767 mph) thunder is a “sonic boom”

Thought to be the 1st photograph of a tornado (1884) Tornadoes Thought to be the 1st photograph of a tornado (1884)

Tornadoes Violent windstorms that take the form of a rotating column of air Extends downward from a cumulonimbus cloud Lower pressure in the center vortex near the ground causes air to rush in from all directions. Air spiraled upward around the core until it merges with parent thunderstorm deep in a cumulonimbus tower.

Tornado Development Less than 1% of thunderstorms produce tornadoes Most intense tornadoes are associated with supercells (big, cumulonimbus cloud structures).

Tornado Classification Fujita Intensity Scale- Assesses the damage produced by a storm as it relates to wind speed. F0- Moderate; 40-72 mph F5- Severe; 261-318 mph Path of Destruction Duration

Tornado Frequency in the US

Tornado Frequency Around the World

Cool Tornado Pictures

Hurricanes

Hurricane Formation Strike the Caribbean, Gulf of Mexico and the US originate in Africa Begin as low pressure storm systems over land Trade Winds blow them out over the warm water of the Atlantic Ocean

Continued Growth Water over the Atlantic Ocean near Africa is warm (80°F) and has lots of moisture in it Precipitation begins, the rain and cool downdrafts of the Cumulonimbus system are not enough to cut off the updraft (it’s too warm) Warm, moist air continues to fuel the system of Cumulonimbus clouds, making them bigger, and bigger, and bigger

Hurricane Dangers Most dangerous component of a hurricane is “Storm Surge” As the storm makes landfall, a mound of ocean water (driven by strong winds AND the “sucking” power of the strong low pressure system) is pushed on shore

Hurricane Classification The Safir-Simpson Scale Type KNOTS MPH millibars inches of mercury Feet Meters  Damage Depression less than 34 less than 39 ------ Tropical Storm 35 - 63 39 - 73 Category 1 64 - 82 74 - 95 greater than 980 greater than 28.94 3 - 5 1.0 - 1.7 minimal Category 2 83 - 95 96 - 110 979 - 965 28.50 - 28.91 6 - 8 1.8 - 2.6 moderate Category 3 96 - 113 111 - 130 964 - 945 27.91 - 28.47 9 - 12 2.7 - 3.8 extensive Category 4 114 - 135 131 - 155 944 - 920 27.17 - 27.88 13 - 18 3.9 - 5.6 extreme Category 5 136+ 156+ less than 920 less than 27.17 19+ 5.7+ catastrophic