1. Weather

2. Weather is....
Weather: The state of the atmosphere at a specific time and place

3. Temperature Thermometer is used to measure temperature.
TEMPERATURE=the average motion of molecules
↑ TEMP= ↑movement of molecules= feels hot
↓ TEMP= ↓movement of molecules= feels cold

4. Warm air= expanding or rising air= leaves behind L pressure
Cold Air=sinking air= leaves an area of H pressure
Air Pressure

5. What causes winds?
A wind is a horizontal movement of air from a area of high pressure to an area of low pressure
It is this difference in pressure that makes the air move (wind)
Winds are measured by direction and speed
The anemometer is the tool we use to measure this
Wind chill=↑ cooling the wind causes

7. Local Winds: The land cools and heats faster than the ocean
Local Winds: The land cools and heats faster than the ocean. Water holds heat longer than land, and takes longer to heat or cool.
During the day, the land gets hotter faster than the water.
The heated air rises, leaving behind an area of low pressure.
Wind from the cooler sea blows in to take the place of that warmer air.
SEA BREEZE:

8. Land Breeze: At night the lands cools off faster than the sea
Land Breeze: At night the lands cools off faster than the sea. Cool air sinks creating an area of high pressure. Wind blows from the land to the sea.

9. Intense heat = Powerful CONVECTION
Warm, moist air rises and leaves behind an area of low pressure. This is why most rain forests are found along equatorial regions.
That air rises until it reaches the top of the troposphere, where it can’t rise any further.
It spreads out towards the polar regions: HOT follows COLD wanting to share its warmth.
As it spreads it begins to cool and sink, sinking air produces an area of H pressure with dry conditions= desert regions on earth

10. Humidity
Humidity: measure of the amount of water vapor stuck between molecules in the air. Temperature*
The hotter the air, the more water the air can hold
Cold air: molecules move slower so droplets of water can start to stick together=condensation
100% = air is saturated (rain)
Temperature at which air becomes saturated is the dew point.
A hygrometer is used to measure humidity.

12. Air Masses
Air masses are masses of air that have the same characteristics of the surface over which it develops
Pressure Systems
descending (going down)=H pressure
ascending (going up)=L pressure

13. This is the symbol for a warm front
warm air slides over departing cold air and large bands of precipitation form

14. This is the symbol for a cold front
Cold Fronts
Cold air pushes under a warm air mass. Warm air rises quickly and narrow bands of violent storms form

15. This is the symbol for an occluded front
2 cold air masses merge and force warm air between them to rise quickly. Strong winds and heavy precipitation will occur

16. This is the weather map symbol for a stationary front
Warm or cold front stops moving. Light wind and precipitation may occur across the front boundary

17. Reading a weather map
Isotherm: Connects areas of equal temperature; therm means temperature

18. Reading a weather map
ISOBAR= connects areas of equal pressure. BAR comes from BARometric pressure