<ul><li>To form they need: </li></ul><ul><li>Warm ocean water </li></ul><ul><li>Low pressure </li></ul><ul><li>High humidity </li></ul><ul><li>Coriolis effect </li></ul>If any of these is missing, a hurricane cannot form!
Hurricanes usually begin their development over the warm waters west of Africa.
Notice how this hurricane got worse over the dark red (warmer water) and finally died when it got over the colder water.
A storm surge is the change in sea level produced by wind pushing the water up onto the shore. It is the MOST damaging part of a hurricane.
Thunderstorms can produce tornadoes, hail, and lightning.
How do thunderstorms form? First, cumulus clouds form. http://www.freewebs.com/
If enough energy and moisture is available, they grow huge! http://serbian.wunderground.com
http://blog.weatherbug.com What do you see happening in this cloud diagram?
Lightning occurs during thunderstorms. Lightning is very common in Georgia. What causes it?
One region within the cloud builds up a positive charge and the other a negative charge. The bottom of the cloud usually ends up being negatively charged and the top positively charged. If the build up (separation) of charge becomes great enough, the negative charges may leap to the positive.
A lightning strike can heat the air in a fraction of a second. When air is heated that quickly, it expands violently and then contracts, like an explosion that happens in the blink of an eye. It's that explosion of air that creates sound waves, which we hear and call thunder .
Tornadoes - rapidly turning, funnel shaped clouds. http://img.metro.co.uk Some are small, some are not! http://www.nssl.noaa.gov
Develop when humid, warm air from the Gulf of Mexico runs into cold, dry air from Canada.
Most tornadoes occur in an area called Tornado Alley! http://www.nssl.noaa.gov
<ul><li>If there is lightning, avoid touching anything metal. </li></ul><ul><li>If outside during lightning, do not take shelter under a tree! </li></ul><ul><li>If there is a tornado nearby, move to a basement or bathroom on the lowest level of your house. </li></ul><ul><li>Stay away from windows. </li></ul>
Watch – event could occur, conditions are favorable. Warning– it is on its way to you! Be sure you know the difference between a watch and a warning!
Flash floods occur when water from a storm cannot run off quickly enough.
Floods occur when water in a river overflows it banks because of heavy rain upstream.