1. Welcome Back! 10/7/2012 1.Why is it important to understand how weather occurs? 2.What types of weather conditions did you observe over the weekend? 3.Describe a Maritime Tropical front (moisture/temperature). 4.What happens when two air masses collide? DO NOW!

2. Activator Weatherman freaks out over “THUNDERSNOW” in ChicagoTHUNDERSNOW 2 MINUTES 2 MINUTES - Think, Pair, Share: What unique weather phenomenon have you experienced? (Ex: Tornado, Hurricane, Blizzard, etc.)

3. Key Vocabulary W EATHER : The physical condition of the atmosphere at a specific place and time

4. Key Vocabulary S TORM : Natural disturbance in the earth’s atmosphere that involve air pressure, clouds, precipitation, and strong winds. Types of Storms: – Thunderstorms – Hurricanes – Tornadoes – Winter Storms

5. Thunderstorm Foldable What are they? How do they form? How are thunder & lightning produced? Picture

6. What are they? Turbulent weather – presence of lightning & acoustic effect on atmosphere (thunder) Cause strong winds, heavy rain, and sometimes sleet, snow, hail

7. How do they form?form Rising warm & humid air causes cumulonimbus* clouds to build upward into a thunderhead Cumulonimbus = Tall cumulus cloud

8. How are thunder & lightning produced? Water droplets & ice inside cumulonimbus cloud break up and become electrically charged. Big electric voltage between + and – charges = discharge (lightning) Heat produced by lightning mixes with local air  thunder

9. Picture