1. AIR MASSES AND FRONTS

2. OCTOBER 27, 2014 QOD: What brings changes in the weather? OBJ: Apply how differential heating of the Earth’s surface and atmosphere drives convection within the Earth’s system. HW: Complete the question sheet

3. WHAT IS METEOROLOGY? The study of hydrometeors and atmospheric phenomenon Examples: Rain, Hail, Sleet, Snow, Drizzle, Graupel, Snow Pellets, Fog

4. GRAUPEL

5. HAIL Largest Hail Stone in U.S. Vivian, South Dakota 8” in Diameter

6. WEATHER VS CLIMATE

7. Weather is the current state of the atmosphere. Climate is the average weather over a long period of time.

8. HOW DOES THE EARTH WARM UP? Direct sunlight form the sun. Some of the Earth receives more sunlight than other areas. Why is the equator warmer than the Poles?

9. AIR MASSES 5 Main types of air masses

10. AIR MASSES 5 Main types of air masses. Continental Tropical (cT)- Warm and Dry Continental Polar (cP)- Cold and Dry Maritime Tropical (mT)- Warm and Humid Maritime Polar (mP)- Cold and Humid Artic (A)- Colder and Drier than cP

11. GLOBAL WIND SYSTEMS http://earth.nullschool.net/

12. FRONTS A narrow transition zone, or boundary, between disparate synoptic scale air masses whose primary discontinuity is density. It is synoptic scale along the length of the front but mesoscale across the front.

13. COLD FRONT Cold, dense air displaces air and forces the warm air up along a steep front Usually forms vertically developing clouds, i.e. Cumulus, Cumulonimbus, Supercell Thunderstorms

14. WARM FRONT Advancing warm air displaces cold air. Gradual increase in clouds Carries in warmer, more humid air masses

15. LOW PRESSURE Air rises in surface low pressure systems. The winds rotate counter-clockwise around low pressure systems These systems usually bring a significant change in weather

16. HIGH PRESSURE Air sinks in a surface high pressure system Winds rotate clockwise around a high pressure system Usually brings dry, quiet weather

17. LET’S TAKE A LOOK! http://www.hpc.ncep.noaa.gov/