Hurricane FormationEl Nino

Warm-up: water cycle review. Label the arrows with these terms:

What are the 2 possibilities for precipitation that hits the land?

1.Runoff 2. Infiltration (to groundwater)

Evaporation

Transpiration

Precipitation

Condensation

http://viewpure.com/jB7t4KKV38Uhttps://www.brainpop.com/science/weather/hurricanes/

• Label Hurricane Katrina (2005) with the below terms and describe what happens at each one:

• Which direction did Hurricane Katrina spin? Counter-clockwise

• Which direction do all storms in the N.H. spin?• Counter-clockwise

Eye – sinking air, very calm. No wind.

Eyewall – STRONG upward winds; strongest part of storm!

Spiral rain bands – heavy rain and storms; gusty winds.

How do these play a role in the formation of a hurricane?

1. Convection – Causes Warm air to rises then it cools sinks, forming circular motion in the atmosphere.

2. Air Pressure - Very low pressure system in the center of a hurricane forms causing winds to rise upward because the air is warm and less dense.

How do these play a role in the formation of a hurricane?

3. Water Cycle – Warm water Evaporates then the water cools in the upper atmosphere and condenses into clouds, and then it rains (precipitates).

1. Hurricanes, Cyclones, and Typhoons are all names we use to describe the same weather phenomenon. 2. All of these storms form around the equator.

3. Why do you think they form there?They form there because the water in the tropic regions just north or south of the equator are the warmest. They are generally the warmest during late summer (hurricane season)4. The warmer, the water, the more violent the storm.

• Hurricanes happen when the oceans have been warmed during summer months. In the North Atlantic, hurricane season is from June 1 to November 30, but most hurricanes happen during the fall.

Wrap it up:

a. What does a hurricane need as “fuel” to form?• Warm water!!! (80˚ F/27 ˚C)

b. What is one of the best ways to “kill” a hurricane? (how does it die)• Go over land!!!• Move into cooler water.

Storms headed towards the Americans come together off the West Coast of

Africa.

Water Vapor rises and wind speeds increase.

Storms begin to rotate.

Storms organize and form a center of extreme low pressure.

http://www.pbslearningmedia.org/resource/ess05.sci.ess.watcyc.hurrlife/how-hurricanes-form/

150 years of Atlantic OceanHurricane Data

http://www.cbsnews.com/htdocs/natural_disasters/hurricanes/framesource_flash.html

Fill in the 6 steps to hurricane formation

1. Warm air rises over the ocean near the equator.

2. Condensation of clouds form.

3. Winds start circling; the eye of the storm is created. As the storm travels, wind speed increases.

4. Circling winds hit up to 74 mph or more. (Wind speed determines category)

5. As it reaches shore, storm surges flood the area.

6. The storm begins to fade out as it comes onto land.

El Niño

http://esminfo.prenhall.com/science/geoanimations/animations/26_NinoNina.html

Questions1. What is an El Niño?

Usually strong trade winds WEAKEN causing warm water and rain to spread across the Pacific Ocean.

2. How does this impact the world?In the Summer:Asia/Australia – DroughtSouth America - Poor Fishing due to warmer waters.

3. Are surface water temperatures warm or cold off the coast of South America during an El Niño?

Warm

4. How does El Nino affect the United States?In the Winter:Strong storms in the Northern states Warm and rainy weather in the Southern states.

5. Does El Nino affect Texas specifically?Yes, Texas experiences warmer and more rainy winters.

6. Are there more frequent hurricanes during El Nino? Why?No. Weaker hurricane season in the Atlantic Ocean.