Fronts March 2011

Bell Work 1. Using a psychrometer, figure the relative humidity in the classroom. 2. Yesterday, there were high, curl or “wispy” clouds in the sky, indicating a change in the weather. What type of clouds were they? 3. Which type of air mass may cause the type of weather we are seeing today? 4. If thunderstorms were to roll in Mt. Gilead later on this afternoon, which kind of clouds would you expect to see?

Bell Work What do the following letters represent in an air mass? (m) (c) (P) (T)

Cloud Quiz 1. stratus 2. cirrus 3. cumulus 4. nimbo (nimbus) 5. alto 6. strato 7. cirro

Front 1. Front- Boundary that forms when two different air masses meet

Cold Front Map symbol Weather Conditions Cold fronts move fast, producing thunderstorms, heavy rain, or snow Cold air meets and moves a warm air mass

Warm Front Warm air meets and over-rides a cold air mass Map symbol Weather Conditions Nimbostratus clouds, Usually drizzly rain After the front passes, weather is clear and warm. Warm air meets and over-rides a cold air mass

Occluded Front Map symbol Weather Conditions Cool temperatures with large amounts of precipitation Fast moving cold air mass overtakes a slower moving warm air mass. Warm air ↑

Stationary Front Map symbol Weather Condition Usually drizzly After the front passes, weather is clear and warm Cold air mass meets a warm air mass with little horizontal movement