Derecho Strikes the Eastern United States

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    Image acquired June 29, 2012

    On June 29, 2012, a windstorm started in northwestern Indiana, and traveled roughly 600 miles (1,000 kilometers) eastward to the Atlantic Ocean. Embarking on a roughly 10-hour journey, the fast-moving storm toppled trees, downed power lines and left more than a million residents without power in the District of Columbia alone.

    The storm was what meteorologists call a derecho. Deriving its name from the Spanish term for “straight ahead,” derecho storms generally blow in one direction. They do not swirl like tornadoes, but they can cause tornado-style damage. The U.S. National Oceanic and Atmospheric Administration (NOAA) reported that the wind gusts in the June 29 derecho rivaled those of an EF-1 tornado.

    This photo, also available from the NOAA storm summary, was taken in LaPorte, Indiana, on the afternoon of June 29. It shows a shelf cloud on the leading edge of the derecho. These long, flat clouds are often associated with thunderstorms, and the massive windstorm that swept over the eastern United States was also associated with thunderstorms—a long line of them stretching for hundreds of miles.

    The June 29 derecho occurred along the boundary of two air masses. In the north, the air was stable and dry. In the south, the air was unstable and moist. And hot. The Capital Weather Gang reported that, before the derecho began, areas affected by the southern air mass were facing record-high temperatures—109 degrees Fahrenheit (43 degrees Celsius) in Nashville, Tennessee, and Columbia, South Carolina; and 104 degrees (40 degrees Celsius) in Washington, DC. This hot, humid air provided fuel for the windstorm, which pulled the air skyward, then returned it in violent downdrafts.

    Derechos have occurred before, and were actually given their name in the late nineteenth century. They occur most often in the Midwestern and Great Lakes regions of the United States, between May and July. To qualify as a derecho, a storm must cause damage over 240 miles (400 kilometers) and pack wind gusts of at least 58 miles (93 kilometers) per hour. The June 29 derecho damage extended over a much greater length, and the storm brought wind gusts of more than 90 miles (145 kilometers) per hour. The June 29 storm did not just qualify as a derecho. It was, according to the Capital Weather Gang, “one of the most destructive complexes of thunderstorms in memory.”

    Photo courtesy Kevin Gould / NOAA. Caption by Michon Scott.

    Credit: NASA Earth Observatory

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    NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission.

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    eny space captain, and 126 other people added this photo to their favorites.

    View 8 more comments

    1. Canuck with a camera 33 months ago | reply

      Oh my goodness. Just look at the price of gas! :)

    2. lindseyannee 33 months ago | reply

      learn something new every day! awesome!

    3. dodagp 33 months ago | reply

      Perfectly captured and described !!!

    4. Pyrrhos 33 months ago | reply

      WoW, excellent photo !

    5. petrus.13 33 months ago | reply

      foto sempre molto interessanti

      my last pic:
      Freedom Red Passion
      Seen in my contacts' photos. ( ?² )

    6. Crimson Wolf 33 months ago | reply

      I was almost exactly where it first started. Got a few pictures, too. Knocked out power to my company so I got to go home early.

    7. Ben_Lepley +_+ 33 months ago | reply

      What is the historical precedence for a Dericho in the US? did it happen in the Dust bowl at all?

    8. Heather_Wright 33 months ago | reply

      truly frightening to see this line of clouds... never experienced this in my lifetime

    9. encouragement 33 months ago | reply

      Amazing storm, but regular gas at $3.07? Haven't seen either one of those in a long time here in CA.

    10. Smile Moon 33 months ago | reply

      Incredible! Thank you, NASA, for the education!

    11. ♫ joyousjoym~ Blessings♥ 33 months ago | reply

      What an Awesome and Amazing image ! ive seen this kind of storm over our house here in merritt island florida ,and wow they are so awesome and ive never been able to capture it on my camera like you have ! for some reason it never seems to come out the same as it really is ! you have captured its awesomeness for sure here!
      Amazing storm and image !

    12. sethlefkow 33 months ago | reply

      Derecho -- straight ahead? Tsk, tsk. How dumb of me. I had always thought it meant "right", like izquierdo means "left".

    13. World Resources 33 months ago | reply

      This image was used in the post More Extreme Weather: Say Hello To Our Changing Climate

    14. StAlbans&Jamaica 33 months ago | reply

      Just to alert the whole world and people who don't know there's only five months left, remember that.

    15. vue3d 31 months ago | reply


      Nice work I like well.

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