• homogenous in temperature and humidity
• source regions - nearly homogenous surface
  • large extent of land or water
    
    
• Maritime Tropical (mT)
• Continental Tropical (cT)
• Maritime Polar (mP)
• Continental Polar (cP)

Fronts

• Fronts - where unlike air masses don't easily mix
  • like meeting of the "Zax"
  • frontal (vertical) lifting occurs
  • zone of precipitation
    
    
• cold front
  • steep "snout-like" slope
  • pushes air rapidly up
  • high intensity rainfall (precip)
    
    
• warm front
  • gentle slope
  • gently overrides colder, denser airmass
  • assoc. with high cirrus clouds preceeding storm
  • drizzle or light intensity rainfall
    
    
• occluded front
  • latter part of storm dissipation
  • cold front merges with warm front
    
    
• stationary
  • neither front moves
  • stalled fronts (unpredictable weather)