Yarnell 19

Tuesday, May 12, 2015

The Yarnell 19

From Facebook page:

R.I.P 19 firefighters killed in Arizona Yarnell Hill fire

Wind Shift info (updated 2015)

That afternoon on the fire, thunderstorm activity was present. Winds on the fire shifted 180 degrees from South/Southwest to North/Northeast and caused a major shift in the direction, speed and intensity of the fire.

Time lapse video of wind & weather during incident:
A photographer in the area happened to catch this wind shift in time lapse video from an area near Congress AZ (south and west of the entrapment site) along a dirt road off Hwy 89. The incident site is in a bowl on the opposite side of the ridge from the photographer. The time lapse condenses about 20 minutes into 17 seconds of video. Here is his link to the video:

Click here for wind shift video at Matt Oss photography

Post-incident wind modeling simulation:

An animation was developed after the incident using wind modeling which simulates and re-creates the spread of the Yarnell Hill Fire and the wind direction and speed. Note there are two specific wind shifts. One significant change occurs at about :30 in the video and could be perceived as the predicted outflow event. A second wind shift at 1:00 shows the arrival over the fire of the outflow from thunderstorms to the north.

Click here for wind simulation