1. Severe Weather Thunderstorms, Tornadoes, Hurricanes, etc…

2. Thunderstorms Thunderstorms are most often associated with a Cumulonimbus Cloud Thunderstorms are most often associated with a Cumulonimbus Cloud This is a cloud that forms when air is forced high into the atmosphere (against its will) This is a cloud that forms when air is forced high into the atmosphere (against its will) Cold fronts often create this condition Cold fronts often create this condition The process that forms a thunderstorm is very fast The process that forms a thunderstorm is very fast

3. Lightning Lightning is believed to be created by friction between the rising and falling air in a cumulonimbus cloud Lightning is believed to be created by friction between the rising and falling air in a cumulonimbus cloud This friction creates a static charge This friction creates a static charge Eventually there is a discharge between positive and negative charges, creating a “spark” a.k.a a lightning bolt Eventually there is a discharge between positive and negative charges, creating a “spark” a.k.a a lightning bolt

5. What is a blizzard? Blizzards are intense winter storms with winds of 35 m.p.h. or higher with falling and/or blowing snow to reduce visibility below ¼ mile for at least three hours. Blizzards are intense winter storms with winds of 35 m.p.h. or higher with falling and/or blowing snow to reduce visibility below ¼ mile for at least three hours.

6. How does it form? Just like a thunderstorm, a lot of warm moist air rises creating clouds and precipitation. The cold weather causes the precipitation to form as snow instead of rain. Just like a thunderstorm, a lot of warm moist air rises creating clouds and precipitation. The cold weather causes the precipitation to form as snow instead of rain.

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

8. Tornadoes Violent windstorms that take the form of a rotating column of air that extends down from a cumulonimbus cloud. Violent windstorms that take the form of a rotating column of air that extends down from a cumulonimbus cloud. Because of the lower pressure in the center, air near the ground rushes into the tornado from all directions. Because of the lower pressure in the center, air near the ground rushes into the tornado from all directions. Air streams in to the funnel, and spirals up into the sky. Air streams in to the funnel, and spirals up into the sky.

9. Tornado Development Most intense tornadoes are associated with supercells (big, cumulonimbus cloud structures). Most intense tornadoes are associated with supercells (big, cumulonimbus cloud structures). Warm Air quickly rises into the sky, as wind blows across the column of air it begins to spin Warm Air quickly rises into the sky, as wind blows across the column of air it begins to spin This creates an area of low pressure. The spinning air is pulled into the low pressure creating a funnel cloud. This creates an area of low pressure. The spinning air is pulled into the low pressure creating a funnel cloud.

10. Tornado Classification Fujita Intensity Scale- Fujita Intensity Scale- – Assesses the damage produced by a storm as it relates to wind speed. F0- Moderate; 40-72 mph F0- Moderate; 40-72 mph F5- Severe; 261-318 mph F5- Severe; 261-318 mph –Path of Destruction –Duration Problem: Doesn’t take into account for structural integrity of objects. Problem: Doesn’t take into account for structural integrity of objects. The ENHANCED Fujita Scale (EF – Scale) is now used in the US. It DOES take into account structural damage (but still uses a 0-5 numerical scale) The ENHANCED Fujita Scale (EF – Scale) is now used in the US. It DOES take into account structural damage (but still uses a 0-5 numerical scale)

11. Watches & Warnings Tornado Watch Tornado Watch –Conditions are ideal for a tornado to be created. Tornado Warning Tornado Warning –An actual tornado has been sighted in the area or is indicated by weather radar.

12. Tornado Frequency in the US

13. Cool Tornado Pictures

21. Hurricanes

22. Hurricane Formation The hurricanes that strike the Caribbean, Gulf of Mexico and the US start in Africa as a low pressure storm The hurricanes that strike the Caribbean, Gulf of Mexico and the US start in Africa as a low pressure storm The Trade Winds (a major wind system for the planet) blows the storm out over the warm water of the Atlantic Ocean The Trade Winds (a major wind system for the planet) blows the storm out over the warm water of the Atlantic Ocean

23. Hurricane Growth Low pressure pulls in air and pushes it up into the atmosphere Low pressure pulls in air and pushes it up into the atmosphere Air temperatures cool and the warm moist air forms big storm clouds Air temperatures cool and the warm moist air forms big storm clouds Lots of heat is released during condensation creating very fast winds Lots of heat is released during condensation creating very fast winds

24. Continued Growth The water over the Atlantic Ocean near Africa is warm (80°F) and has lots of moisture in it The water over the Atlantic Ocean near Africa is warm (80°F) and has lots of moisture in it The warm, moist air continues to fuel the system of Cumulonimbus clouds, making them bigger, and bigger, and bigger The warm, moist air continues to fuel the system of Cumulonimbus clouds, making them bigger, and bigger, and bigger

25. Hurricane Movement Once the growing low pressure system is out over the warm water of the Atlantic Ocean, the winds blow it west Once the growing low pressure system is out over the warm water of the Atlantic Ocean, the winds blow it west Because the oceans are relatively smooth (no land) it has plenty of time to get bigger and stronger Because the oceans are relatively smooth (no land) it has plenty of time to get bigger and stronger

26. Tropical Depressions, Tropical Storms and Huricanes Hurricanes start as “Disturbances“ Hurricanes start as “Disturbances“ Once they move out into the ocean they become “Tropical Depressions” Once they move out into the ocean they become “Tropical Depressions” When they reach a wind speed of 39 mph they become “Tropical Storms” and are given a name When they reach a wind speed of 39 mph they become “Tropical Storms” and are given a name When they reach a wind speed of 74 mph it becomes a Hurricane. When they reach a wind speed of 74 mph it becomes a Hurricane.

27. Hurricane Names Hurricanes are named based on a list created by the national hurricane center. Hurricanes are named based on a list created by the national hurricane center. There are a total of 6 lists of names that are used every six years (the 2014 names will be used again in 2020) There are a total of 6 lists of names that are used every six years (the 2014 names will be used again in 2020) If a Hurricane creates enough devastation to be remembered it’s name is retired. If a Hurricane creates enough devastation to be remembered it’s name is retired.

28. Hurricane names Answer to a previous question: Answer to a previous question: There once was a Hurricane Bob. The name was retired. There once was a Hurricane Bob. The name was retired.

29. List of names 201420152016201720182019 Arthur Bertha Cristobal Dolly Edouard Fay Gonzalo Hanna Isaias Josephine Kyle Laura Marco Nana Omar Paulette Rene Sally Teddy Vicky Wilfred Ana Bill Claudette Danny Erika Fred Grace Henri Ida Joaquin Kate Larry Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda Alex Bonnie Colin Danielle Earl Fiona Gaston Hermine Ian Julia Karl Lisa Matthew Nicole Otto Paula Richard Shary Tobias Virginie Walter Arlene Bret Cindy Don Emily Franklin Gert Harvey Irma Jose Katia Lee Maria Nate Ophelia Philippe Rina Sean Tammy Vince Whitney Alberto Beryl Chris Debby Ernesto Florence Gordon Helene Isaac Joyce Kirk Leslie Michael Nadine Oscar Patty Rafael Sara Tony Valerie William Andrea Barry Chantal Dorian Erin Fernand Gabrielle Humberto Imelda Jerry Karen Lorenzo Melissa Nestor Olga Pablo Rebekah Sebastien Tanya Van Wendy

30. Hurricanes, Typhoons and Cyclones We give different names to Tropical Storms that develop, depending on their location We give different names to Tropical Storms that develop, depending on their location Atlantic: Hurricane Atlantic: Hurricane Pacific: Typhoon Pacific: Typhoon Indian: Cyclone Indian: Cyclone They are all the same exact type of storm. They are all the same exact type of storm.

31. Hurricane Classification The Safir-Simpson Scale TypeKNOTSMPHmillibars inches of mercury Feet Meter s Damage 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

32. Hurricane Dangers The most dangerous component of a hurricane is the “Storm Surge” The most dangerous component of a hurricane is the “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 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 More people die as a result of drowning, than do of strong winds More people die as a result of drowning, than do of strong winds

33. A Hurricane’s “Death” As a hurricane makes landfall, the supply of warm, moist air that was fueling it is cut off As a hurricane makes landfall, the supply of warm, moist air that was fueling it is cut off This may take days and 100’s of miles This may take days and 100’s of miles