NSSL scientists study tornadoes in their own backyard

May 24, 2011 Oklahoma tornadoes

Seven destructive tornadoes struck Oklahoma on May 24, 2011.  The tornadoes were well forecast by the National Weather Service (NWS), and NSSL was in position to capture the storms in several ways.

NSSL’s dual-polarized X-band mobile radar captured the early and mature stages of the first tornado reported near Canton Lake, Okla.  The data will be compared with another X-band dual-polarized radar for accuracy.  This storm produced an EF-3 tornado.

The phased array radar successfully sampled a tornadic supercell every one minute as it evolved and went on to produce devastating EF-4 damage in towns west of Oklahoma City, Okla.  A comparison of PAR data with the damage path shows that the radar captured rotation in the storm 12 minutes before it touched down. This tornado was on the ground for two hours with a 75-mile long track.

Visiting forecasters in the NOAA Hazardous Weather Testbed 2011 Spring Experiment found it interesting to be under the threat of tornadoes and then to be in the forecast path of them.  They watched the storms out the window and on the National Weather Radar Testbed Phased Array Radar along with the area Terminal Doppler Weather Radar and the NWS NEXRAD.  These radars showed the evolution of two confirmed tornadic debris balls as both storms moved towards Norman, Okla.  Participants also reported the NSSL/CIMMS weather-adaptive 3D variational data assimilation system (3DVAR) products all handled the track and evolution of the storms and tornadoes very well.

The American Red Cross of Central Oklahoma began using NSSL’s Warning Decision Support System – Integrated Information (WDSS-II) to map rotation tracks of the storm and deploy their teams by 8 a.m. the next day.

And, several NSSL scientists have been in the field as part of NWS teams to survey the tornado tracks and assign EF-Scale ratings based on the damage they find.  The EF-Scale is an estimate of the strength of the tornado based on damage to structures and vegetation.  Preliminary results show three tornadoes out of the seven in central Oklahoma were ranked a violent EF-4.

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NSSL videographer wins national award

A focused Murnan

NSSL videographer James Murnan was just awarded a 2011 INDUS Excellence Award.  Murnan was one of five recipients in the entire company of 500 employees.  INDUS holds the federal Information Technology contract at NSSL.

Murnan has made significant contributions to present the NOAA mission through the NOAA Weather Partners Office of Communications and External Affairs, social networking sites and the Internet.

Murnan has written scripts, shot video, produced and created more than 30 videos over the past few years on topics ranging from phased array radar technology to the Coastal and Inland Flooding Observation and Warning project (CI-FLOW). In addition he has produced more than 11 podcasts and video b-roll for reporters.

In response to the April 27, 2011 tornado outbreak in the south, Murnan quickly recorded and edited interviews with the director of the Storm Prediction Center and an NSSL research meteorologist.  The video was posted the following day on a NOAA.gov tornado outbreak summary page, NSSL’s Facebook page and the NOAA Weather Partners YouTube site: http://www.youtube.com/user/NOAAWP.

His latest big project was another video for the “That Weather Show” series titled “The Dual-Polarization Zone.”  This video explains the weather radar scanning technology being added to NEXRAD radars using spoofs of popular commercials.  “The Dual-Polarization Zone” has been viewed almost 7,000 times.

Murnan’s ingenuity and creativity helps present NOAA’s critical mission to the public in understandable terms.

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Valuable severe weather dataset collected by students

The NSSL/CIMMS Severe Hazards Analysis and Verification Experiment (SHAVE) are collecting hail, wind damage and flash flooding reports through phone surveys from now through mid-August.  This is the sixth year of the project, logging more than 29,000 hail reports, 5500 wind reports and 9300 flash flood reports since the project began.

SHAVE reports, when combined with the voluntary reports collected by the NWS, creates a unique and comprehensive database of severe and non-severe weather events and enhances climatological information about severe storm threats in the U.S.  Some NWS forecast offices use SHAVE data to assist in verifying their warnings.

Largely student led and run, the SHAVE team makes phone calls along the path of a target storm.  People who answer the calls are questioned about hail size, wind damage and flash flooding that occurred over the past 60 minutes.  The phone data is blended with radar information on Google Maps to create a database on the storm for research.

NSSL/CIMMS researchers are using the SHAVE datasets as verification for multi-radar, multi-sensor detection algorithms and techniques, dual polarized radar, and a system that automatically detects supercell thunderstorms.

Because SHAVE leans heavily on students, it gives them rich opportunities for professional development and leadership.  It has also led to year-round undergraduate research assistantships and research projects for over half of the participants.  Between 2006-2011, 26 students have worked for SHAVE.

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