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How scientists are trying to predict wildfire movement

It’s been six months since the most deadly and destructive wildfire in California history, the Camp Fire, which killed 85 people and burned 19,000 structures in November 2018. But even at the peak of the inferno, some scientists moved toward it, in an attempt to understand more about the intensity and spread of the flames. Science correspondent Miles O’Brien has the harrowing inside look.

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  • JUDY WOODRUFF:

    It's been six months since the most deadly and destructive fire in California history, the Camp Fire.

    Tonight's edition of PBS' "NOVA" is a harrowing first-person account of that disaster and where it fits into a global trend toward more frequent massive infernos.

    The documentary, "Inside the Megafire," comes from Miles O'Brien.

    And, for us, he explores how researchers are breaking new ground in understanding the dangerous spread and intensity of the flames.

    It's part of our regular series on the Leading Edge of science.

  • Man:

    This has got potential for a major incident.

  • Miles O’Brien:

    When first-responders arrived at the Camp Fire, the flames were already so fierce and the winds so strong, they had trouble getting close to the fire.

  • Man:

    Eyes on the vegetation fire. Got about a 35 -mile-per-hour sustained wind on it.

  • Miles O’Brien:

    Fanned by high winds, fed by drought-stressed trees, the fire moved incredibly fast, consuming an acre of forest every second. A horrific scenario was unfolding that also presented an opportunity for scientists to better understand how wildfires spread.

  • Craig Clements:

    We're not going to — we're not going to get through here. They are doing active suppression right there. Let's go up and see what we can find.

  • Miles O’Brien:

    So meteorologist Craig Clements and his team from San Jose State University sped right toward the inferno.

    In the crosshairs, Paradise, California, a town of 26,000 nestled in the Sierra Mountains. It was the morning of November 8, 2018, and everyone who lived there had to leave in a hurry.

  • Man:

    Just got to get the (EXPLETIVE DELETED) out of Dodge. This is getting heavy.

  • Miles O’Brien:

    They were forced to run a gauntlet through flames. There are only four roads that lead off the mountain. And all of them were perilous.

  • Woman:

    Oh my God, there's fires everywhere. I don't want to die here. I don't want to die.

  • Man:

    Please get out of town. And as you're going out of town, please be careful.

  • Miles O’Brien:

    With the frantic exodus still under way, we drove in the opposite direction, eventually meeting up with Clements and his team close to the fire line.

    They had found a relatively safe vantage point to gather some unprecedented data. We are driving in a one-of-a-kind custom rig. The scientists hope to use it to peer into the fire in a way that no one else has before.

  • Craig Clements:

    We need to better understand fire spread. And the meteorological data is one of the key components. And yet we never measure things on an active wildfire. We usually use a satellite. We see plumes in the radar, which is great. But we're not really seeing what's going on right here.

  • Miles O’Brien:

    Plumes, the columns of smoke and gas that rise from the flames, are more than a sign of fire. They also create their own weather.

    And Craig Clements suspects that they actively spread the fire. But how? To understand, he aims a sophisticated lidar right at the plume. Lidar is like radar that uses a laser beam instead of radio waves. It bounces off the smoke particulates as they are propelled by the wind and returns information about speed and direction.

  • Craig Clements:

    We have been able to slice through a plume with our lidar. And we have been able to measure the rotation and the wind field associated with the rotating column, and so that's pretty exciting.

  • Miles O’Brien:

    The plumes at fires like these are complicated systems. As hot air rises, cooler air rushes in. It's called fire-induced wind.

  • Craig Clements:

    We don't know how that fire-induced wind from the plume interacts with pushing the fire front. If the plume goes up, does any air or smoke come back down? And if it does come back down, can that spread the fire in different directions?

    It's these interactions that we call fire atmosphere interactions, and we don't have a great handle on how they propagate fire spread.

  • Miles O’Brien:

    A big factor in the exponential spread of the Camp megafire, spotting. Hot embers, also called firebrands, launched and carried by 50-mile-an-hour winds landed as much as a mile ahead of the fire front.

    New spot fires started again and again, rapidly, randomly. But exactly how spotting fuels the growth of megafires is one of the big unknowns in wildfire science.

  • Craig Clements:

    So, it's still blowing northeasterly.

  • Miles O’Brien:

    Craig Clements hopes his work might lead to some answers.

  • Craig Clements:

    This is a real strong low-level jet coming down off the mountains.

  • Miles O’Brien:

    Right now, wildfire prediction models are not sophisticated enough to factor in all of the complexities of the atmosphere and terrain. And they don't account for spotting at all.

  • Craig Clements:

    We are trying to forecast how many spot fires there will be, and that's something no model right now can handle.

  • Miles O’Brien:

    At the National Center for Atmospheric Research in Boulder, Colorado, they're leveraging their expertise modeling weather and climate to give teams on the ground battling a wildfire a better sense of what the future holds.

  • William Mahoney:

    Fire is very challenging to predict because there are a lot of factors that are involved that are not really atmospheric or traditionally atmospheric.

  • Miles O’Brien:

    Atmospheric scientist William Mahoney showed how the latest models can see trouble as it brews, in this case, close to home. The Cold Springs Fire happened 16 miles west of Boulder in the little town of Nederland in July of 2016.

  • William Mahoney:

    There was good data from this particular event in terms of how the fire progressed, the burned area boundary. And that made for really good verification data for our model, so we can then use that to fine-tune the rate of spread and the heat content and flame length information.

  • Miles O’Brien:

    The model is designed to allow them to predict the rate of spread of the fire 18 hours in advance, and run what-if scenarios for different moisture levels in the forest.

  • William Mahoney:

    We're trying to simulate the general characteristics of a fire, but we will definitely not be able to say at this second and then in this location a tree is going to burn or a building is going to burn.

    You really almost need to know every tree, every bush, every piece of grass and what its state is to really predict what's going to happen.

  • Miles O’Brien:

    Fire ecologist Jennifer Balch and her team from the University of Colorado are trying to find more precise, more efficient ways to assess forest health, so that the models can be more accurate.

    She is focused on eight 30-by-30-meter plots, many of which were heavily damaged by the Cold Springs Fire. Their work begins on the ground in the traditional way.

  • Woman:

    It looks like 3.8.

  • Miles O’Brien:

    Once the trees are precisely measured and characterized on terra firma, Balch and her team fly a drone 100 feet above each plot.

    The drone carries sensors that capture the same parts of the spectrum as those on board NASA satellites. By comparing these higher-resolution drone scans with images from space, she hopes to find the dots and connect them. The Holy Grail? Understanding how a forest is doing from space.

  • Jennifer Balch:

    My hope is that we can actually get away from the intensive fieldwork and use drone-based observations, airborne, and satellite-based observations to understand what's going on across thousands of trees.

  • Miles O’Brien:

    To better understand the big picture, scientists who study wildfires need to explore them up close. On a good day, it's laborious, on a bad day, perilous.

  • Man:

    If anything happens, we got to go, and we — our escape route is this way.

  • Miles O’Brien:

    By the time it was over, the Camp Fire was the deadliest and most destructive in California history; 85 people died. Nearly 19,000 structures were destroyed.

    For scientists, the stakes justify the risk.

    For the "PBS NewsHour," I'm Miles O'Brien in Paradise, California.

  • Judy Woodruff:

    Well, that's something.

    There is much more in tonight's program than we could include here.

    "NOVA"'s "Inside the Megafire" airs on most PBS stations and streams online tonight at PBS.org/NOVA.

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