Eagle Creek Fire Behavior Analyst Video Link and Transcript
Incident: Eagle Creek Fire Wildfire
Good morning, my name is Dan Pearson I’m with Southwest Incident Management Team 2. I’m the Fire Behavior Analyst for the team and today I’m going to be talking about the rain and its effect on the fire. So the Eagle Creek Fire is currently around 48,000 acres and we have been receiving precipitation for about the last two days however that rain is not coming in equal amounts on all parts of the fire. On the southwest corner of the fire we have received 3-5 inches depending on the location of rain in the last 48 hours. As those clouds move east they strike the Pacific Crest Trail and the cascade divide which forces the clouds higher in the atmosphere, acting kind of like a squeegee, squeezing the water out of the clouds. After the clouds continue on to the east by the time they get up toward Cascade Locks and Shellrock Mountain they’ve lost a lot of the available precipitation so only about an inch of rain has struck the ground. Sounds great in theory cause it is one inch of rain so it is really helping, however, it’s not enough yet.
So, this is an example of what we call a “plug” of fuels down near Shellrock Mountain. So you’ve got this top layer of litter and duff so when the rain strikes, yeah it absorbs in and pretty much stops the fire behavior on the surface, but it’s pretty thick as you’ve got a lot of dead and down that are larger limbs and branches beneath this thick layer so at the very top layer there will probably be about a half an inch that’s absorbing that one inch of rain over two days. Fire can continue smoldering down subsurface and if it dries out too quickly then it will dry out the top surface litter layer and continue with a ground fire. More precipitation is forecasted, approximately another 2-3” of rain so that will really help, but one other thing to think about, the dead and down material is not solid, it’s been degrading and starting to rot so it’s pretty flaky and can actually hold heat. Once it’s exposed to the flame front, if this hasn’t had enough precipitation over a significant period of time, this will continue to smolder. So if you’re driving on I-84 around Cascade Locks and Shellrock Mountain especially, you’ll continue to see some live flame and smoke being produced but it’s just stuff like this burning out, it’s not actually moving. So yesterday in six hours the fire moved four feet, that is 1/100th of a chain per hour and that growth is expected to continue to decrease in the coming days as more precipitation continues to move into the area. So you’ll see some smokes, they’re not actually going anywhere, you don’t need to call them in to 911. Thank you.