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Yarnell Hill Fire
Yarnell Hill Fire El Reno Tornado Storm Safety Tracking

 

Yarnell Hill Fire Tragedy - 19 Granite Mountain Hotshots overtaken by the fire on June 30, 2013

Documentary video link:  Geographic Analysis of the Yarnell Hill Fire

Granite Mountain Hotshots

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Video link of sketch and oil painting:  Last Stand at Yarnell Hill Fire

Oil painting completed by Bruce Willhite from sketch provided of the Granite Mountain Hotshots as they cleared and started burning out the brush around them.  The crew was cutoff by a flaming front at 4:39 PM that suddenly cut off their retreat to their designated safety zone, a ranch house in the distance.  A thunderstorm going up 40,000 feet that had developed moved past the fire.  In this case the thunderstorm, known as a "Low Precipitation Supercell" created a cyclonic tornado along with an anticyclone circulation within the hook region similar to the tornado producing storms researched in the Central Plains. 

At 4:37 PM a radio call from the Granite Mountain Hotshot location in the basin was made that the next tanker airdrop for Yarnell was on a good path and was clearly visible.  At 4:39 PM it is likely that the rear flank downdraft is responsible for rapidly pushing the fire across their basin cutting them off from their retreat.  As the crew was preparing deployment of their shelters in preparation for the flaming front the supercell thunderstorm had moved past the fire eliminating the uplift conditions causing the tornado fire column to rapidly collapse and quickly propagating over the mountain range.  A rating of this tornado would not be possible since the damage indicators used for rating tornadoes would have been consumed by the fire. 

The collapse at 4:42 PM was super heated and overtook their retreat basin and then their original fire line area by 4:46 PM.  The collapse subjected the area to temperatures in the 2000 degree range throughout as was noted by the extensive granite rock spalling present.  (Large flakes of rock separating due to being subjected to the high heat and rapid cooling).   It is important to note that had the crew stayed at their original location which was considered black (burnt fuels) it too was overtaken by the superheated column collapse and would have necessitated shelter deployments.  Unfortunately, current shelter designs limit temperatures to around 300 degrees.  In volcanic terms, pyroclastic flow happens when gravity takes hold as the superheated material is not able to rise.  In this case, removing the clastic (rock) and inserting ash we have a pyroash flow as the rapidly burning and unburnt fuels being consumed during the tornado phase fall. 

The gust front from the Prescott thunderstorms arrived about 5:00 PM as photographed and witnessed on the north side of the fire.  This gust front was long after the 4:42 PM deployment and it brought with it rain and moist air reducing the fires intensity except for the far northwest corner and the area around the collapse.

 

June 30, 2013 Yarnell Hill Fire, Arizona

By Tom Dolan

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional Research updates will be posted soon.  Photos, radar data, field research notes, lessons and training opportunities.

 

Copyright 2011-2016 by Tom Dolan. All rights reserved. Federal copyright law prohibits unauthorized reproduction.

 

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Last modified: 05/10/19