todd abel: that's what changes our environment.nd that's what causes our injuries and some of our fatalities. kyle dickman: it was a warning to the hotshots that by the afternoon of june 30, they could be dealing with a fire that was completely different than it was behaving in the morning. [music playing] kyle dickman: two things that firefighters pay the most attention to, fuels and weather. paul hessburg: weather is one of the ficklest parts of a wildfire. mark finney: aside from drought or dry conditions, the wind is probably responsible for the greatest variation. another aspect of the wind that makes wildfires dangerous is the shifting direction. the wind can be coming out of the west, for example, and suddenly shift to coming out of the north. todd abel: so thunderstorm developments, it'll push wind multiple directions. [lightning crackling] brad elder: we've all been standing outside watching a front hit and suddenly get hit by this wall of wind. kyle dickman: what happens with these thunderstorms, they start to rain. brad