1 / 41

Air Masses, Clouds, and Fronts

Air Masses, Clouds, and Fronts. The “nuts and bolts” of day-to-day weather analysis and forecasting. Frank Brody / Brian Hoeth National Weather Service Spaceflight Meteorology Group Johnson Space Center Houston, TX. Weather and the Space Shuttle. The Space Shuttle cannot fly:

jorden-alvarado
Download Presentation

Air Masses, Clouds, and Fronts

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. Air Masses, Clouds, andFronts The “nuts and bolts” of day-to-day weather analysis and forecasting Frank Brody / Brian Hoeth National Weather Service Spaceflight Meteorology Group Johnson Space Center Houston, TX

  2. Weather and the Space Shuttle • The Space Shuttle cannot fly: • Through thick low clouds • Through rain and snow • Near thunderstorms • Near lightning • In winds that are too strong • In strong turbulence

  3. High and Low Pressure Isobars: Lines of constant pressure • aka “anticyclone” • Sinking air • Usually associated w/ fair weather • aka “cyclone” • Rising air • Usually associated w/ clouds and precipitation

  4. Forces and Winds • Forces creating wind • Pressure Gradient Force • Coriolis Force • Frictional Force “Use the Force”

  5. Pressure Gradient Force The pressure gradient force results in a net force that is directed from high pressure to low pressure

  6. Coriolis Force

  7. Geostrophic Wind • Wind blows parallel to isobars (lines of constant pressure) • Clockwise around High Pressure • Counterclockwise around Low Pressure

  8. Frictional Force • Cause: Surface of earth is rough • Effect: Slows the wind down  Coriolis force weakens, pressure gradient force becomes dominant • Result: Converging winds near lows and diverging winds near highs.

  9. Cyclonic Circulation

  10. Cold Fronts

  11. Warm Fronts

  12. Stationary Fronts

  13. “Classic” Frontal Pattern

  14. Occluded Fronts • Cold front and warm front merge • Further lifts already rising warm air • Typically associated w/ intense, mature cyclones

  15. How to Read a Weather Map Temperature Pressure Weather Wind Dew Point

  16. And now … It’s time for a pop quiz …

  17. A warm front exists when ___ air is rising over ___ air • (a) cold, warm • (b) hot, moist • (c) warm, cold • (d) cold, stable

  18. A warm front exists when ___ air is rising over ___ air • (a) cold, warm • (b) hot, moist • (c) warm, cold • (d) cold, stable

  19. At the surface, winds tend to flow ___ and ___ towards a center of a low pressure center • (a) clockwise, outward • (b) counterclockwise, outward • (c) clockwise, inward • (d) counterclockwise, inward

  20. At the surface, winds tend to flow ___ and ___ towards a center of a low pressure center • (a) clockwise, outward • (b) counterclockwise, outward • (c) clockwise, inward • (d) counterclockwise, inward

  21. The pressure gradient force results in a net force that is directed from ___ to ___ • (a) high pressure, low pressure • (b) low pressure, high pressure • (c) left, right • (d) right, left

  22. The pressure gradient force results in a net force that is directed from ___ to ___ • (a) high pressure, low pressure • (b) low pressure, high pressure • (c) left, right • (d) right, left

  23. Clouds • How clouds are formed? • Types of clouds • Cumulus • Stratus • Cirrus • Nimbus • Clouds by height • High: Cirro • Mid: Alto • Low: Strato

  24. Cloud Formation • Clouds form when air is cooled to its dewpointor when the air reaches saturation. • Air rises  Lower pressure  requires work  Air is cooled! • Cooler air holds less water vapor  some of the vapor condenses  CLOUDS!

  25. Cloud Types

  26. Clouds by Height

  27. Cirrus – “Curl of Hair” Thin, wispy clouds composed of ice crystals

  28. Stratus -”Layer” Layered low clouds, sometimes patchy with poorly defined edges

  29. Cirrostratus Cirro prefix: High Cloud Cirrus: “Curl of Hair” Thin, wispy clouds Stratus: “Layer” Poorly defined edges “Halo around the sun”

  30. Cumulus – “Heap” Fair weather cumulus – small heaps of scattered clouds w/ flat bottoms and round tops Altocumulus – common ahead of cold front

  31. Altocumulus Cumulus: “Heap” Flat bottoms, round tops Alto prefix: Mid Cloud

  32. Stratocumulus Cumulus: “Heap” Flat bottoms, round tops Strato prefix: Low Cloud StratoCumulus – • Dark fluffy clouds • Relatively stable air • Not as menacing as it may appear

  33. Nimbus – “Rain” Cumulonimbus - Cumulo: “Heap” Nimbus: “Rain” Easier Translation: “Thunderstorm cloud” Nimbostratus - Widespread thick layer of cloud with poorly defined edges producing precipitation

  34. Got any questions or have we left you in a fog??? Thank you for coming … buh bye now!!

  35. Contact Info/Websites • Frank Brody:frank.brody-1@nasa.gov • Brian Hoeth:brian.r.hoeth@nasa.gov • http://www.srh.noaa.gov/smg • http://ww2010.atmos.uiuc.edu • http://virtualskies.arc.nasa.gov/main/mweather.html • http://www.srh.weather.gov/jetstream/ • http://www.windows.ucar.edu

  36. Backup Slides

  37. FRICTIONAL FORCE

  38. FRICTIONAL FORCE

More Related