Experimental VIIRS DNB Outage Composite for Moore, Oklahoma

During the afternoon of May 20, 2013, the city of Moore, Oklahoma was struck by a large, violent tornado that caused widespread damage and numerous fatalities.  Some aspects of the tornado and the resulting damage are observable from space.  As with Superstorm Sandy and Hurricane Isaac, the VIIRS day-night band can be used to monitor changes in light resulting from a variety of features, such as moonlight reflection off of cloud tops or the surface, lightning from thunderstorms, fires, or human activity.  The images below show day-night band imagery prior to the major tornado as observed in the early morning of May 20 and an image obtained in the early morning of May 21.  In the May 21 image, thunderstorms continued east of Oklahoma City.  Reflected moonlight provides imaging of ongoing thunderstorms and the DNB captures a few lightning flashes.  Clearing skies over the Oklahoma City area help to identify the outages resulting from the tornado several hours earlier.  When pre- and post-event imagery are combined in a 24-bit RGB image, reductions in light output appear in shades of light yellow across the Moore, OK area.  Changes in cloud cover between the two days result in other shades of blue to identify cloud contamination where the RGB change product is not applicable.  A zoomed-in portion for Oklahoma City is shown in the final image.

Many SPoRT team members have spent time in the Oklahoma City area as students at the University of Oklahoma in Norman, or through collaborations with other scientists at the National Weather Center.  Our thoughts are with our colleagues in Moore and the citizens of Oklahoma during their recovery efforts.

Day-night band imagery from the VIIRS sensor aboard the S-NPP satellite show city lights, cloud cover, and lightning during the early morning hours of May 20 prior to the storms over Moore, OK and the Oklahoma City area.

VIIRS DNB imagery during the early morning of May 21 show city lights in the Oklahoma City area, but reduced light output in Moore, OK as a result of the major tornado that occurred during the afternoon of May 20. Storms from earlier in the day had shifted eastward, still visible in the DNB imagery.

When pre- and post-storm imagery are combined in a 24-bit composite, power outages in the Moore, OK area are evident in shades of yellow. Other areas appear yellow, such as Tulsa, OK, but this is a result of changes in cloud cover between the two scenes.

Zoomed in area of the outage composite focusing on the Oklahoma City area.