Chapter 11: Cyclonic Storms Flashcards
What is the smallest and largest cyclonic storm?
Smallest= thunderstorm Largest= Hurricane/Typhoon
How do thunderstorms form?
When there is moisture, atmospheric instability and a lifting mechanism
-Rising air cools causing some of the water vapour to convince which forms cumulonimbus clouds for thunderstorms
What are 3 things that cause air to rise?
- Differential heating- uneven heating of the ground and air creates pockets of warm air called thermals which tend to rise
- Cold fronts- warm air goes over colder air
- Terrain
How long to thunderstorms cells last?
30 mins
what are he 3 stages in the lifecycle of a thunder storm?
- Towering cumulonimbus stage: clouds grow up with turbulence at the edges
- Mature stage: air moving in both un and down directions
- Dissipating stage: downdrafts dominate and the upward supply of warm moist air is cut off
what are the 3 other types of thunderstorms?
- Multi cell storms
- Line cell storms
- Supercell thunderstorms
Proper definition of a hurricane?
Sever cyclonic tropical storm in North Atlantic Basin. Originating in the tropics and rotate counterclockwise
what are the 5 steps in the formation of a hurricane?
- Cold front+ warm from coming together from opposite directions
- Boundary between the 2 fronts isn’t in a straight line
- Both fronts are moving to the right (counterclockwise)
- Denser cold air moves faster than the warm air. Lifts the cell upward, creating a low pressure area
- As the air is lifted, it expands and cools adiabatically and reaches dew point.. Clouds develop over low pressure area. Eventually a front forms that has been lifter completely off the ground
Where do hurricanes begin?
With a disturbance in the westward flowing air near the equator. temp must be 26C or warmer
-water rises and condenses in these warm tropic areas, which releases large amounts of latent heat which is the main source for a hurricane
What are the classification stages before a hurricane?
Tropical wave > Tropical storm > Hurricane
What is hurricane wind velocity?
When winds travel fast and counterclockwise sooner the eye
What is storm centre velocity?
At the same time, when the storm is being pushed by regional winds
What do you get when you combine hurricane wind and storm centre velocity?
It creates a significant difference in effective wind speed on opposite sides of the storm
What are the primary effects hurricanes have on oceans?
Sea swells which are long period waves that move in all directions from the storm enter and can be 6-12 hours ahead of the storm
Where did Hurricane Andrew touch down?
Homestead south of Miami as a category 4