Note: Atmospheric Profiles are Included to Properly Interpret Radar Data.

Atmospheric Profile - Ft. Worth, Texas - 6 PM CST - January 8, 2008
(Note: When Temperture and Dewpoint Lines Join the Humidity is 100%)

• Profile Shows Strong Temperature Inversion With Top Near 7,500 Feet
  
  
• Normally Temperatures Decrease With Height
  
  
• When Temperatures Increase With Height an "Inversion" is Present
  
  
• At the Top of a Temperature Inversion a "Super Refraction" of Radar Waves May Occur.
  
  
• Super Refraction Can Cause the Radar to Pick Up Ground Targets (e.g. Cars)
  
  
• Visible Light Can Also Be Refracted by Inversions Resulting in "Mirages"
  
  
• The Winds Were From the Northwest Below About 25,000 Feet
  
  
• Above 25,000 Feet The Winds Were West to Southwesterly

Graphic Showing Potential for Refraction of Radar Waves in the Atmosphere.

• Graphic is Based on Atmospheric Profile Above
  
  
• Atmospheric Height Increases Left to Right
  
  
• Lower Numbers (Longer Blue Bars in Above Graphic) Show Higher Potential For Super Refraction (Downward Bending) of Radar Waves
  
  
• For Land Stations Radar Index (Change/1,000 FT) The Average Value is -12
  
  
• Radar Index Values < -24 Are Considered Favorable For Super Refraction of Radar Waves
  
  
• Refraction Index is Very Strong at 4,900 FT (-40) & 5,300 FT (-25)
  
  
• Super Refraction (Downward Bending) of Radar Waves Could Occur For Targets < 5,300 FT
  
  
• This Indicates a Possibility That Radar Could Pick up Ground Targets at a Distance
  • Ground Target Detection Unlikely Because All Indices > -49