Tuesday, May 1, 2012

The Tornado Chronicles: Medford, OK Tornado of April 30, 2012

A strong tornado took place near Medford, Oklahoma during the late evening hours of Monday, April 30, 2012. The above photo was shown on News9 in Oklahoma City, which appears to show the tornado as it was approaching the Medford area.

I believe the above photo is a screen grab of the following video by Ben Holcomb. Look closely during the lightning flashes and you can see the well defined tornado and large debris field at times:

You can view his full still photo stream by going to this link.

Nighttime tornadoes are always particularly dangerous (for obvious reasons - its dark, some folks are asleep, etc.).  This tornado appears to have been quite strong based on radar, especially when it was further to the West of Medford.

In the last 15-20 years, I've only seen the following scenario take shape on radar a half dozen or so times - and it's always been associated with a strong or violent tornado. The first image shows the radar near Jet, OK in reflectivity (rain, hail, etc.) mode.  This was taken when the tornado was still to the West of Medford (as noted toward the right center portion of the image - click to enlarge): 

Note the "donut hole" within the reflectivity pattern just to the left of the center of the image (I  have circled it in white for easier identification).  That was the location of the tornado at the time this image was taken (at 8:57 pm CDT).  The "donut hole" phenomenon takes place when a large tornado (and/or the parent circulation within the storm) is drawing rain in around itself.  This is why we always point out that a "rain wrapped" tornado is very dangerous as you likely won't be able to see it coming.

Now lets take that same radar image and switch over to velocity (wind speed and direction) mode from the exact same time:

Remember, when looking at velocity imagery, the red shadings reflect wind blowing away from the radar, and the green shadings reflect wind blowing toward the radar.  The radar is located just off the left hand side of the image.

I believe the tornado was likely at its strongest near this time (as shown above on the radar imagery), and thankfully weakened (as well as decreased in size) as it neared the city of Medford proper (probably just before the video  was taken).  

The Oklahoma Mesonet (an automatic weather observation station) location 1 mile Southwest of Medford recorded an 84 mph wind gust and a dramatic drop in pressure at about 9:10 pm CDT:

According to the radar, the tornado likely moved just to the South of the site, sparing a direct hit both it as well as, more importantly, the city of Medford.  Preliminary reports indicate damage to "hundreds" of utility poles throughout a mostly rural area from near Medford to West of Deer Creek.  Damage was also reported at the Hohmann electrical substation to the West of Deer Creek.

There were also reports of damage to rural homes, outbuildings and barns, however we do not yet know the extent of the damage, nor their exact locations.  I would suspect most of the damage would have taken place along that same rural swath from near Medford to West of Deer Creek, as described above.

The National Weather Service (NWS) in Norman has just published the following track map based on radar approximations and spotter/chaser reports.  The tornado track from just South of Medford to just North of Deer Creek is the one that we've been talking about in this particular post:

If you have interest in this tornado event, please bookmark this post and check back for more updates as they become available.

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