1 / 15

Weather

Weather. Part 5: Weather Patterns. Air Masses. Large bodies of air Movement of them causes changes in weather Cover thousands of square kilometers Properties fairly uniform Classified by where they form. Continental – form over continents; relatively dry

bethan
Download Presentation

Weather

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Weather Part 5: Weather Patterns

  2. Air Masses • Large bodies of air • Movement of them causes changes in weather • Cover thousands of square kilometers • Properties fairly uniform • Classified by where they form • Continental – form over continents; relatively dry • Maritime – form over oceans; relatively humid • Polar – cold • Tropical - warm

  3. 4 Major Air Mass Types in USA 1. Maritime tropical – • Forms over ocean near the equator • Warm, moist air • Most commonly affects Eastern states • In summer brings hot, humid weather • In winter brings rain or snow if it encounters a cold air mass

  4. 4 Major Air Mass Types in USA 2. Maritime polar – • Forms over northern Atlantic and northern Pacific oceans • Cool, moist air • Bring cloudy, damp weather to Northeast and Pacific Northwest

  5. 4 Major Air Mass Types in USA 3. Continental tropical – • Hot and very dry • Forms over the desert southwest and Mexico usually during summer • Affects southwest states, plains, and Mississippi valley and can bring record high temperatures

  6. 4 Major Air Mass Types in USA 4. Continental polar – • Cold and dry • Forms over Canada • Often dominant weather in winter • Brings very cold weather • Can also bring clear, pleasant weather to the North in summer

  7. Major Air Mass Types • mT = Maritime Tropical • mP = Maritime Polar • cT = Continental Tropical • cP = Continental Polar cA = Continental Arctic (5th type) Brings extremely cold temperatures with very little moisture, originate north of the arctic circle in winter

  8. Fronts • A front is a boundary that forms when two air masses with different properties meet • Weather is usually unsettled and stormy along a front. 4 types of fronts: • Cold • Warm • Occluded • Stationary

  9. Cold Front • Cold air mass meets and pushes under a warm air mass • Pushes warm air up • Can cause violent storms • Fair, cool weather usually follows a cold front • Generally move northwest to southeast • Can cause a rapid drop in temperature of more than 15° in one hour

  10. Cold Front • Weather symbol: blue triangles point in the direction the cold front is moving http://commons.wikimedia.org/wiki/File:Example_of_a_cold_front.svg

  11. Warm Front • Warm air overtakes cold air and goes over it • Showers followed by hot, humid weather • Noticeably warmer after the front passes • Generally move southwest to northeast

  12. Warm Front • Weather symbol: Red, semicircles pointing in the direction the warm front is moving http://commons.wikimedia.org/wiki/File:Example_of_a_warm_front.svg

  13. Occluded Front • A cold front moves faster than a warm front • When a cold front overtakes a warm front an occluded front forms • Usually form around low pressure areas • At the occluded front the cold air mass meets the cool air mass that was ahead of the warm front • Warm air rises to form cumulonimbus or nimbostratus clouds bringing precipitation

  14. Occluded Front • Weather symbol: purple, alternating triangles and semicircles pointing in the direction the front is moving https://commons.wikimedia.org/wiki/File:Occluded_cyclone.svg http://commons.wikimedia.org/wiki/File:Occlusiefront.png

  15. Stationary Front • When warm air meets cold air and no movement occurs • Rain may fall for many days • Weather Symbol: Alternating blue triangles pointing towards the warmer air and red semicircles pointing towards the colder air

More Related