Narrative:

We were taxiing to runway 19L northbound on taxiway J when tower advised a tornado was 5 mi south of the field moving north. Several mins later ground control advised they were evacing the tower for an approaching tornado. Facing north with the tornado behind us and approaching was not a good feeling. We decided to taxiway east on J2 and at the intersection of J2 and taxiway K we turned the aircraft facing southwest so we could see the tornado. It was approaching our area so we decided to follow several other aircraft and proceed south on runway 19L to stay out of its path as well as allow the aircraft behind us to get out of the way. The captain followed the lead of several aircraft ahead of us and declared his intentions on ground control frequency and declared an emergency. We taxied south on runway 19L and exited on K5 and watched the tornado touch down on runway 19R then clear the area to the north. I feel we acted in the best interest of safety for ourselves and the line-up of aircraft behind us who needed to get out of the way of the twister. I am writing this report because we taxied onto the runway without clearance as the tower was evacuate/evacuationed and nobody was there to control the field. Approximately 20 other aircraft did the same thing and we all communicated with one another on ground control frequency.

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Original NASA ASRS Text

Title: B737 FLT CREW DECLARES EMER AND TAXIES WITHOUT CLRNC TO AVOID A TORNADO AFTER TWR IS ABANDONED.

Narrative: WE WERE TAXIING TO RWY 19L NBOUND ON TXWY J WHEN TWR ADVISED A TORNADO WAS 5 MI S OF THE FIELD MOVING N. SEVERAL MINS LATER GND CTL ADVISED THEY WERE EVACING THE TWR FOR AN APCHING TORNADO. FACING N WITH THE TORNADO BEHIND US AND APCHING WAS NOT A GOOD FEELING. WE DECIDED TO TXWY E ON J2 AND AT THE INTXN OF J2 AND TXWY K WE TURNED THE ACFT FACING SW SO WE COULD SEE THE TORNADO. IT WAS APCHING OUR AREA SO WE DECIDED TO FOLLOW SEVERAL OTHER ACFT AND PROCEED S ON RWY 19L TO STAY OUT OF ITS PATH AS WELL AS ALLOW THE ACFT BEHIND US TO GET OUT OF THE WAY. THE CAPT FOLLOWED THE LEAD OF SEVERAL ACFT AHEAD OF US AND DECLARED HIS INTENTIONS ON GND CTL FREQ AND DECLARED AN EMER. WE TAXIED S ON RWY 19L AND EXITED ON K5 AND WATCHED THE TORNADO TOUCH DOWN ON RWY 19R THEN CLR THE AREA TO THE N. I FEEL WE ACTED IN THE BEST INTEREST OF SAFETY FOR OURSELVES AND THE LINE-UP OF ACFT BEHIND US WHO NEEDED TO GET OUT OF THE WAY OF THE TWISTER. I AM WRITING THIS RPT BECAUSE WE TAXIED ONTO THE RWY WITHOUT CLRNC AS THE TWR WAS EVACED AND NOBODY WAS THERE TO CTL THE FIELD. APPROX 20 OTHER ACFT DID THE SAME THING AND WE ALL COMMUNICATED WITH ONE ANOTHER ON GND CTL FREQ.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.