There were a number of thunderstorms surrounding the Yarnell fire on Sunday. And while meteorologists don't have complete data to determine the origin of the winds, observations from the site are consistent with the kinds of strong, gusty, erratic winds one would associate with multiple storm fronts, Klimowski said.
Yarnell sits in a corner of the Peeples Valley, bounded on three sides by mountains. That complex terrain likely helped funnel the winds in changing directions, said Chuck Maxwell, a predictive services meteorologist with the Southwest Coordination Center.
"What you ended up with was maximum potential for chaos," Maxwell said.
An eye on the sky for the boots on the ground
Those conditions persisted through Monday and only slackened slightly Tuesday with the arrival of slightly cooler temperatures and light precipitation.
The ongoing severe weather has kept many fire crews at bay, though most of the wildland firefighters in Arizona have by this point been deployed to the site. Federal firefighting agencies were poised to take over management of operations Tuesday evening, shortly after the national fire preparedness level rose from 2 to 3.
At preparedness level 3, multiple geographic regions require significant support from federal resources. The highest level is 5, reached only during the most severe wildfire years.
In addition to the boots on the ground, areal and logistical support, the federal government often provides incident meteorologists (IMETs) to fire teams operating on-site. These IMETs are embedded in National Weather Service offices around the country and are deployed at the request of firefighting command posts once a post has been established.
Because the Yarnell Hill fire moved so quickly, command posts were still being established when the 19 hotshots' position was overrun, Maxwell said.
Speaking during a tour of the operations floor of the National Oceanic and Atmospheric Administration's Center for Weather and Climate yesterday, acting NOAA Administrator Kathryn Sullivan said that hotshot crews are often chief candidates for IMET support.
"Not to be overly speculative, but typically, we would have our IMET embedded with the kind of hotshot crew that was overrun by fire on Sunday," she said. "That kind of extremely rapid wind shift that turned the fire against them, that's just the kind of impending hazard, rapid, fast-moving hazard, that the IMETs try to protect the firefighters from."
Stephanie Paige Ogburn contributed to this report.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500