Science in the Spotlight: Forecasting wildfire behavior
Watch on YouTubeVideo summary
Although the overall frequency of wildfires across the nation has not shown a significant upward trend over the last fifty years, their severity has escalated dramatically, with just one percent of fires accounting for more than eighty percent of the burned area in the western United States. This intensification is driven by larger, hotter fires that burn through vast landscapes, posing particular hazards at the Wildland-Urban Interface where human activity increases ignition risks and exposure. While fire remains a natural process, these "bad fires" are exacerbated by factors such as beetle-killed trees and decades of aggressive suppression policies that allowed fuel to accumulate, contrasting with traditional Native American practices of frequent prescribed burns which prevent dangerous buildup.
Accurate forecasting relies on numerical models that use current atmospheric conditions to predict future states, yet these tools face significant challenges including imperfect weather data, difficulties in observing conditions near active fires, and the complexity of characterizing fuel moisture and quantity. To address the chaotic nature of fire systems, scientists employ probabilistic approaches using ensembles of simulations rather than relying on single predictions, acknowledging that small errors in ignition timing or location can drastically alter outcomes. Recent advancements aim to improve these models by integrating ground observations with satellite data and machine learning to map fuel conditions across all fifty states, while also modeling embers as hot particles to better simulate how they leapfrog to ignite structures in built environments.
The future of fire behavior prediction involves coupling various disciplines and technologies to create a comprehensive workflow that includes atmospheric, fire behavior, evacuation, human behavior, and traffic flow models. This integration is expected to be enhanced by artificial intelligence working alongside physical models based on physics, with drone teams collecting real-time data on temperature, humidity, wind, and smoke composition to feed these systems. The ultimate goal is to make forecasting as accessible and routine as weather reporting, allowing users to predict fire movement via mobile devices within hours, though the necessity of coupled modeling varies depending on whether fires are driven by strong steady winds or generating their own atmospheric perturbations in calm conditions.
Despite inherent imperfections, models remain vital tools that evolve through an iterative process of optimization using new case studies and collaboration across diverse sectors including chemists, healthcare providers, transportation agencies, utilities, foresters, and hydrologists. Universal integration of data from utility pole-mounted weather stations into high-resolution forecasts is a future aspiration to ensure consistent information flow for emergency decisions. By combining advanced satellites, drones, and sensors with improved observational capabilities, the scientific community aims to refine forecasting further, ultimately protecting infrastructure, managing smoke health impacts, preserving water quality, and reducing the risk of catastrophic conflagrations through better understanding and management of fire dynamics.
Read the full video transcript
Welcome everyone uh to this NSF and CAR
Explorer Series event. My name is Evan
Portier and today we'll be talking about
wildfires and how the US National
Science Foundation National Center for
Atmospheric Research or NSF ENCAR is
working to provide solutions to this
difficult environmental challenge.
Just a couple of housekeeping notes.
This is our second conversation on
wildfires this month and you can find a
link to the previous conversation in our
slido chat. To access the slider chat,
you will just scroll down and enter your
name and click join. You'll also be
greeted with several questions that if
we mind answering, that really would
help us out.
And you can also find more information
about the previous event and our future
events on our website. Just search for
NSF Encar Explorer series and you'll see
our future events about all sorts of
research.
So today we'll be diving into wildfires,
specifically forecasting wildfire
behavior, how wildfires react and spread
under different conditions. And to do
that I am joined uh by NSF ENCAR's Jason
Conneal. Jason, welcome.
>> Thank you Evan. It's good to see you. I
appreciate you arranging this
conversation.
Likewise. And so for the folks in the
audience, Jason, I was wondering if we
could just start off this conversation
just telling a little bit more about
yourself and broadly the work that you
do here at NSFNCAR.
>> I've been at the Foothills Lab at
NSFNCAR since 2001 in a variety of
different capacities.
Most of my background, my education, and
my experience is what we would call sort
of traditional atmospheric science.
studying weather in complex terrain. By
that I mean mountains and valleys and
deserts and coastlines, you know,
weather that really feels what's on the
earth's surface. Uh also over over
cities. So that's that's more or less my
background. But since 2018, I've been
working on projects related to wildfire
and uh it's been a really exciting time
to be in this line of work.
>> Great. And so for folks that don't know,
the Foothills Laboratory is one of our
several campuses here in the Boulder
area and that the research applications
laboratory is one of several labs um
under NSF ENCAR. So like we mentioned
earlier, Jason, we've been hearing a lot
about wildfires um often in the news,
but just conversationally. And so I'm
curious to start off this conversation
to hear your perspective on how these
wildfires are becoming a growing problem
and really a nationwide challenge.
>> Yeah, it sure feels like something has
changed. Uh I I moved to Colorado in the
1990s
and I certainly do not recall wildfires
being talked about so much um and and so
much in the news. So I I I agree with
you. it feels like something has
changed.
So, it's an interesting thing. Uh, one
of the things that has not changed, at
least in the nation as a whole, is the
frequency of wildfires. If if we look
back over the last half century or so,
the last 50 years, yeartoyear, the
number of fires nationwide goes up and
down a little bit, as a lot of things
do, but there's there's really no
overall trend in the number of wildfires
nationwide. There are some trends in
regions of the United States, like in
the western US where we are, we do see a
little bit of an increase in in fires,
but the overall number hasn't changed
much. Now, that number is a shockingly
high number. In in 2025, there were more
than 77,000
wildfires in the United States. And when
you hear a number that large, you might
think, how is it then that we're not
living in a constant state of like smoke
and ash? That's an extraordinary number
of fires. The answer is that most of
those fires are quite small.
They're really inconsequential.
Inconsequential. It It's the way the
distribution of fires work. It's the few
large fires that make the news are the
most troubling to us. And in fact, if
you look over the western United States
in most regions, um about 1% only 1% of
the fires accounts for more than 80% of
the total area burned. So that's that's
why given the high number of fires, we
it's not even worse than it is. So given
that I just said that the number of
fires nationwide isn't showing a strong
trend, why does it seem like it is a
more urgent problem now than it used to
be? It's because the fires that we do
have are burning hotter. They're moving
faster and they're they're burning more
area. And so the severity has gone up
even though the number of fires
nationwide has not particularly gone up.
>> So, so just to recap, it's not that
we're just seeing we're not seeing more
fires just on a nationwide, but what
we're seeing are these really larger
fires that are burning hotter like you
were mentioning. Are these kind of the
mega fires that you were mentioning that
kind of dominate the news like
headlines?
>> They are. They're they're the fires that
um they dominate the headlines because
these are some of the most destructive
fires. They're they're the fires that
are hardest to control. They're the
fires that most threaten people and our
property. And I I think an important
context to everything we're talking
about today is is the recognition that
there are good fires. Wildfire is not
fundamentally a problem to be solved and
suppression of all fires is not the
answer. A lot of landscapes
um have fire as one of their components.
There there are trees that are adapted
to fire and actually require fire in
order to reproduce. So fire itself isn't
really the problem. However, there are
bad fires and these are the fires
generally that um can uh cause us all
sorts of problems, life, property,
the cost of fighting them. And so it's
this is an important way to frame it.
And a lot of I think what we're going to
talk about today is the bad fires and
and the need to forecast them better and
mitigate them as a hazard. But I think
it's important to keep in mind that that
fire is just fundamental to nature. It's
been around on the planet longer than
humans have been around on the planet
and we're not going to suppress them,
nor should we try to suppress all of
them.
And so that's a really good point,
Jason, and thanks for distinguishing
that fire is kind of this natural
process on these ecosystems, but there
is a subsection of fires that we would
deem problematic. And I think one of the
reasons is this wildland urban
interface. And I'm just wondering if you
could touch upon why that is problematic
in in terms of wildfires.
>> Yes, I can. The the the WUI or the WOOI,
the wildland urban interface. Uh I I can
actually show you a picture of of what
we mean by that and it might help other
people uh get a sense of it.
Here is just one example. Um, this is
from Colorado, just up the hills from
where we are right now. And it's it's
the aftermath of um the Buffalo fire in
2018 in Silverthorn. So, if you look at
this picture, what do you see on the
left? You see what we sometimes call the
built environment. This is our stuff.
It's what we have built. It's where we
live. And in the center, you see what we
would call the natural environment.
trees, grassland, sage brush, the
mountains in the distance, and the
Buffalo fire burned through this
wildland urban interface where we and
our stuff sort of meet the natural
environment happens to be some of the
the prettiest places to live. And in
fact, the number of of people in the
United States and in Colorado living in
the wildland urban interface or the WOOI
is uh is high and it's going up
nationwide. about a third of the
population either lives in or works in
the WOOI. And in Colorado, it's even
higher. It's about half. The reason that
the WOOI is such an important topic if
we're going to discuss wildfire is
because not only is it in the WOOI that
often um fires are the greatest hazard
that we're most exposed to fire, but as
we continue to build in the WOOI, there
is the greater chance that we're going
to start fires. In fact, although it
varies quite a bit from state to state,
overall most fires that happen are
started by people. Not necessarily
intentionally. Far more often than not,
it's accidentally. But as we are in
these areas that are fireprone more and
more, not only are we exposed more, but
there's more likelihood that we're going
to cause fire, too.
So, I think this is a really good
context here. So, these fires are
burning hotter. They're burning more
area and but we're also um inventing
ourselves in the this WOOI this wildland
urban interface. And so, we know that
this is a challenge nationwide. And so,
I'm wondering if we can talk a little
bit about the tools that are available
to us to kind of help and predict
wildfires.
And so, you know, conversationally, we
might hear about wildfire forecast, we
might hear about wildfire models, and
I'm wondering if you can kind of tease
apart those two and expand upon what
that really means.
>> Yeah, I'd be happy to. Um, most
generally, uh, predicting wildfire is
somewhat like predicting the weather.
You can do that with many different
kinds of tools. One of the most powerful
is um what we call a numerical model.
This is just a set of computer code that
contains equations that describe how the
atmosphere or fires behave. You take
that code and that'll give you a future
prediction if you also tell the model
what the current state is.
Sort of a trivial but I think meaningful
example of this is if I said to you
you've got a number and I want you to
add five to that number.
What is the result? And you would come
back to me and you'd say I I can't tell
you the result until you tell me what
was the original number. And if I say
well one okay 1 plus 5 is six. So the
point is that these equations that
predict either the state of the
atmosphere in the future or the state of
a fire in the future, they have to have
a starting point. You have to give the
models the current conditions.
So that's how a lot of these numerical
models work. In the case of um the kind
of modeling that we tend to do, not
exclusively, but we tend to do at ENAR,
we see the advantage of coupling fire
models to atmospheric models. The reason
for that is in nature, the atmosphere
and fires communicate all the time. For
example,
fires behave in certain ways because of
atmospheric conditions. Imagine drier
than normal conditions, hotter than
normal conditions, and then you've got
wind on top of that. These are
atmospheric variables, but they're going
to define how a fire behaves. The fire
then in turn communicates back to the
atmosphere. Fires release heat, they
release water vapor, they release gases
and particles into the atmosphere. And
this kind of exchange atmosphere to
fire, fire to atmosphere is happening.
nature all the time. And so we feel that
there's a physical realism that you get
from having what we call coupled
modeling system. That coupling is those
two models, the atmospheric model and
the fire model behaving kind of in
tandem. It's not the only approach.
Models are tools.
And if you imagine other kinds of tools,
you know, for example, tools to clear
snow off the driveway or the front porch
in winter, there's no single tool that's
best for all jobs. Sometimes you need a
15 horsepower three-stage snowblower.
Sometimes a simple broom will do the
job. The same is true of atmospheric
models and fire models.
The complexity that we gain that's an
advantage when we're talking about
coupled modeling
also comes with disadvantages. So
there's greater fe physical realism but
that complexity means that even the most
powerful computers
take a long time to run these models.
And so if you're in a position of
needing a very very fast answer to what
is this fire going to do in 3 hours or 6
hours and I can't wait 15 minutes to
know or an hour to know. I need to know
right now. There are alternative models
that are simplified. They don't capture
the full complexity of nature but they
give you an answer a lot faster. And so
an important thing to keep in mind
anytime we're talking about these
coupled modeling systems is it's one
solution, but it's not the only solution
to solving the problem of predicting
what a fire is going to be doing, you
know, in the next few hours, the next
few days.
So Jason, when you say a couple model,
it sounds like you were saying that
these two systems that you are trying to
represent, so the atmosphere and the
fire are kind of talking to each other.
And is is that a fair thing to say when
we say coupling, does that mean like
there's feedback involved, right,
between the two?
>> There is. Feedback is the perfect word,
Evan. Yeah. I think you've probably
heard, I know I've heard uh in
discussions of some of these mega fires
that you referred to earlier that a fire
is so big that it makes its own weather.
And that's true. The big fires indeed do
make their own weather. Uh but that's
not exclusive to the big fires. Fires in
general make their own weather. But the
degree to which the weather's perturbed
and how far away and how long lasting
the perturbation is sort of scales with
the size of a fire. Imagine a really
small fire, something even as small as
say a campfire.
In my view, a campfire makes its own
weather, too. You sit near it, you feel
the heat. Uh water vapor is being
released. You wouldn't necessarily
notice that. That's invisible, but you
see the smoke. And these are all very
very local small changes, but
nevertheless they're changes of the
atmosphere right around the fire. And I
would say, you know, in my view, they
kind of qualify as weather changes. The
bigger the fire, the the the bigger the
change. And some of these mega fires,
it's just extraordinary uh what they
what they can do to the atmosphere. I've
got a really dramatic example of one
here that I can share with you.
This is what's called a pyrou cumulo
nimbus. It's a huge uh thundercloud.
This one happens to be over the Sierra
uh national forest in California.
Remember that I mentioned that one of
the the feedbacks, great word that you
use. One of the feedbacks from the fire
to the atmosphere is introducing heat
and water vapor and particles. Well, it
so happens that heat and water vapor and
particles are three key ingredients to
making clouds. So, what we'll often see
above the most sustained fires, the
largest fires, is clouds forming.
They're not all necessarily this
visually impressive. Some are just
smaller uh cumuli. Nevertheless, this is
one example of how fires feed back to
the atmosphere. And it's one of the kind
of things that we strive to capture when
we're doing this coupled modeling. It so
happens that pyroumulonus clouds are are
difficult to simulate and there's still
a lot of great research to be done in
that area. Um but it is that kind of
feedback that that we we like to capture
with a couple modeling.
>> Great. So it sounds like one of the
tools that we can use to understand how
wildfires spread and react with
environment are these couple models, but
it's not a like a one-size fit all. It
really is dependent on I guess kind of
those stakeholders or what folks are
needing like you were mentioning if they
need an answer quickly. Perhaps the
couple model is not the the best tool
available here. And so
with that, we we've talked a little bit
about the tools available here and we
know that I think it's kind of just one
of these things people say are like,
"How can I trust the model or how can I
trust this forecast?" And so I'm
wondering if we can just dive into, you
know, wildfires are complex and so there
are challenges to to modeling this,
especially like you mentioned, fires
make their own weather and then the
weather influences the fire. So can we
dive into what are the current
challenges of making or challenges of
getting like accurate forecast?
>> Yeah. Yeah. Absolutely. Um and and
there's so many challenges we we could
be here a long time but I'll I'll just
hit on a few. In in coupled modeling the
more accurate the atmospheric piece of
that coupling is the better. So first
and fundamentally you really want to get
the weather forecast right. weather
forecasts have been improving uh over
the decades on a fairly regular basis
and are much better now than they were a
few decades ago. They're still
imperfect. So um that is one challenge,
you know, getting the atmosphere right.
And in particular when you're talking
about the state of the atmosphere right
near fires when in fact they have been
influenced by the fire uh getting those
observations is really really important
because recall that what I said is you
can have an accurate model but if you
don't give it a good starting point if
you don't tell that model what the
atmosphere's current state is through
observations then it's going to have
errors in it. It's very difficult to
observe the atmosphere right in the
vicinity of fires. Um it's it's a
hostile environment and they at least
wildfires tend to happen where we don't
necessarily have a lot of instruments
deployed.
So that's one challenge. Another
challenge on the fire side is that we
need to know a lot of details about
what is burning. What the we call this
fuel. Fuel is really anything on the
ground that either could be burning or
or is burning. Trees, shrubs, grass in
the natural landscape or unfortunately
in the built landscape. This can be
buildings, it could be cars, it could
really be anything that the flames move
through. We need to have an accurate
characterization of that. and especially
at at high detail because even large
fires are relatively small compared to
the size of a state or the size of the
country.
And so um understanding the the details
of how a fire behaves really means we
need to understand the details of the
state of the fuel through which the fire
moves. The state um really means several
different things. What is it? How much
of it is there? How wet or dry is it?
And we could go into other details, but
those are kind of the the the
fundamental ones. What is it? How much
of it is there? And how wet or dry is
it? So that that's a challenge. Um
>> wait, Jason, can I just interrupt you?
>> Yeah, please do.
>> Going back to our our first one where
you were saying, you know, really one of
the challenges with with accurate
forecasting is the need for
observations. And can you expand like
what do you mean by that to to someone
who's not familiar like what what
exactly do we need?
>> We need observations of the air
temperature, the humidity in the air and
the wind. And more would be even better.
But I say at a minimum those are kind of
the three main variables that we need to
know because fire behavior will be
fairly sensitive to those three
atmospheric variables. In fact, it turns
out turns out go going back to what we
discussed before about the mega fires,
the most dangerous fires, they tend to
be fires where there is a high wind.
These are really wind driven fires. We
know this in Colorado. Um, but it's not
exclusive to Colorado. California has
similar problems. The the fires uh in
Lahina uh in Hawaii th those were wind
driven fires as well. And and this is
true the world over really. If if you
look at some of the most destructive
fires, they tend to be the winddriven
fires. And so getting accurate
observations of the wind in the
immediate vicinity of a fire is really
important. Those are kind of the the
minimum variables that we'd like to see
on the atmospheric side.
Does I hope that answers your question?
>> It does. Yes.
>> Okay. Yeah.
And one one further thing I want to say
about the fuels piece,
it's characterizing fuels in the natural
environment. So again, think trees,
shrubs, grasses.
While not easy, at least we've been
doing that longer and it's a bit more
straightforward than characterizing the
fuels in the built environment. One of
the huge opportunities for for greater
basic science and applied science is
understanding what happens when a fire
makes its way into the wildland urban
interface and starts burning those
fuels, things we don't even want to
think about as being fuels, houses for
example,
we have a lot of trouble representing
that accurately in our models. And if we
cannot accurately, if we don't
understand that problem, then we can't
write the equations. We can't write the
computer code to put that into our
models. And so our models, they kind of
don't really know what to do once a fire
makes its way into the built
environment. We we we can make rough
appro approximations. It's not like we
are truly clueless about it, but if
we're examining what are the areas that
really would benefit from more research,
understanding fires in the wildland
urban interface and even more almost the
purely built environment is, I would
say, yet another challenge is if we're
going down the the list of challenges.
Uh, another one is early detection.
Often when we first notice that there's
a fire, it has been going for a while
and that means it's a bit harder to
respond to
and certainly harder to suppress if it
is one of those what we would call bad
fires. This is a term of art in the
business, bad and good fire. And uh our
response to bad fires
depends on really getting an early
warning. There are ways of doing this.
um satellite technology, cameras, but
there's a long way to go. What we have
found in some of our wildfire modeling
with these coupled models is that if we
introduce a little bit of an error in
the where and when that a fire starts,
you know, we take an ignition point and
we say, let's actually pretend that it
was 1 kilometer away to the north or to
the south or let's pretend it was
actually 6 hours earlier or 6 hours
later than what we believe it to be.
What does that do to our fire simulation
or what would what would have been the
fire behavior forecast at the time?
Sometimes is sometimes it results in in
a dramatic change in the fire. An
extreme case imagine this. You move the
ignition point away from dry brush to
the middle of a small alpine lake.
Suddenly you don't even get a fire
anymore. So that's I mean that's an
extreme example just to drive home the
point that even pretty small errors in
the what or sorry the where and the when
of a fire starting can throw off our
fire behavior predictions by quite a
bit. So that's yet another challenge is
that early detection and getting the
location and the timing down really
well. And then I'll close with one I
would say is the is the la the last
challenge I'll bring up. Certainly not
the cha last challenge we faced. The
atmosphere and fires are chaotic
systems. That doesn't mean they're
random. They still follow the laws of
physics chemistry.
By chaotic, what I mean is they're so
complex and our ability to observe them
is so limited that small errors in how
we code them up in the models and how we
observe them eventually translate to
large errors in the prediction. We have
ways of dealing with this. One way is is
through probabilistic approaches. So
instead of taking a single fire behavior
simulation, giving you a single
prediction of what that fire is going to
be doing three, six hours from now, one
day from now, you actually launch a
whole series of simulations, each of
which is slightly different from the
others, but different in a plausible
way. You don't want to have completely
unrealistic simulations because they do
you no good. But you can have a range.
Sometimes we call these an ensemble, a
collection of equally
probable
um outcomes and then you let all those
model runs go and they give you a
collection of results. It's almost like
crowd sourcing in a way when you're
sourcing a crowd of reasonable experts.
Each of these model simulations is like
an expert but they all differ slightly.
If you take that collection of results,
then you can begin to ask questions
like, what is the probability that this
fire is going to burn to the east or to
the west or is going to be stopped by
that stream? You can talk probabilities
and you get a result that's like there's
a 73% chance or there's a 12% chance.
Then you can make really good objective
decisions about how to employ resources,
where to tell people to evacuate or
maybe not evacuate.
Probabilistic approaches to modeling is
a really good way of dealing with these
chaotic systems. And so doing that
better because it's very computationally
intensive is is the last challenge that
I'll that I'll mention.
>> Great Jason. So, we kind of we were
walking through this where you've um
talked about the tools that are
available, these couple models that
Encar has been developing. You've given
us a lay of the land of some of the
current challenges here. Not all of
them, not an exhaustive list. Um so that
leads us to a natural question. What are
you and your colleagues doing in in this
space? Um and specifically, let's jump
into this um topic of embers because I
find this really fascinating. And so can
you expand upon your work um with embers
and what are embers?
>> Yeah, absolutely. I'd love to do that.
Uh let's let's show you first an example
of the kind of simulation that some of
my colleagues are uh
are working on right now. Let's get this
going. There you go.
This is the East Troublesome Fire
from 2020. It it was notorious for
several reasons. One of which is that in
one 24-h hour period, it grew by
something like, I don't know, 100,000
acres. Most fires never reach 100,000,
let alone grow by 100,000 in a 24-h hour
period. It was heavily wind- driven,
which is something we've talked about
already. And embers figured prominently
in this, as did the importance of
getting the fuels piece right.
And let me let me show you what I mean
about getting the fuels piece right. And
that will lead into answering your
question about some of our latest
advancements here.
What I've got on the screen right now is
uh the observed perimeter. Say you're
you're viewing this from up above. So
you're looking straight down. That white
poly line that you see in those two
panels, and it's the same line on both
panels, that represents the perimeter of
the burned area at some point late in
the fire's lifetime. So that outlines
the area that was burned. What you see
in yellow is what our fire behavior
model predicted would be burned. The two
yellows look different. Why are they
different? Well, on the left, the
smaller predicted burn area, ignored the
fact that this fire burned through
timber that had a large amount of uh a
large number of trees that were killed
by pine bark beetles. So, these are
standing trees, in some cases down trees
that are drier. They're not alive. Um
they're drier than than the living
trees. They tend to burn more readily.
If our model doesn't know that, doesn't
know that there was a lot of beetle
kill, it it tends to underpredict
how far the fire advances. On the right
is what happens if we go into that data
set of the fuels, what is being burned
and we inform the model that a lot of uh
these trees have been killed by beetles,
we get a much more accurate prediction
of the fire. So, one of the things that
that my colleagues are doing is we're
working on ways of improving the realism
of the fuels data sets that go into the
model. Now, I mentioned that um that
this fire, these troublesome fire was
notorious for several reasons. One is
that it advanced
through uh embers that were produced.
And you ask what embers are. So, I've
got a uh an illustration here from the
Forest Service.
Really nice diagram showing what we mean
by embers.
When you have uh fuels being burned,
they will give off bits of material,
glowing hot bits of material that are
still burning, that are carried by the
wind. They tend to rise up because
they're warmer than their environment
and then they're blown downwind.
I'll bring up campfires. Again, you see
this happen with with uh you know, they
almost look like sparks, but they may
last a little longer than sparks. Some
of them are actually like little chips
of wood that especially wet wood can
spit out. You hear this pop and then you
see a little ember flying and you hope
it doesn't land on your tent. These
these are embers. So in extreme cases
really hot fires can produce a lot of
embers and they can be lofted pretty far
and carried downwind.
Being carried down was important for
several reasons. One is it can cross
areas that otherwise would uh get in the
way of the advance of a fire, a stream,
a lake, a road, a parking lot, an
expanse of um the ground that it itself
will not burn. If you've got embers, it
can hop right over those areas. Another
reason embers are important is they can
go way, way downwind from the main fire.
There has been research in Australia,
for example, showing that in some cases,
embers can travel 10 to 20 miles away
from the main fire, land on some burnal
material, and start a new what we call a
spot fire.
That is such as an important it's such
an important mechanism. And it turns out
that in the built environment, the main
way that fire moves from house to house
to house is through embers that land on
rooftops,
land on uh landscaping that is
flammable,
fences. Embers can be sucked into the
vents in the home and ignite the home
from the inside. Embers are the main way
that fire moves from house to house. So
if our goal is to have realistic
simulations of fire behavior in the
built environment, we really need to
account for this. I have a colleague
Maria Frediani who is doing exactly
that.
She has figured out a way to model these
embers by considering them to be more or
less particles in the air. They're big
particles. They are hot particles.
Nevertheless, you can use an approach
that is sort of tried and true and you
can just model them um as particles and
for a lot of fires in the build
environment, that piece is key if you're
going to get realistic results. I've got
a simulation here I can show you of the
infamous Marshall fire
that affected so many of us here at
NSFAR.
This is the fire burning and that yellow
line through sort of the upper middle
part of the figure. That's highway 36.
This simulation again accounts for ember
transport and spot fires. That fire in
the simulation is able to leap across
the highway which itself is not burnable
start additional fires.
You'll also see another characteristic
of this fire is that it expands and
surges.
It tends to move not methodically at the
same pace but in these huge leaps
forward. Some of that is ember
transport. Some of that is just
basically um this was a heavily wind-
driven fire. You might remember at the
time winds exceeded 100 miles an hour in
places. So like a lot of the worst fires
and this was the costliest in Colorado
history. this fire was uh was heavily
wind driven. So those are two areas that
we're we're working on right now is
better characterization of the fuels and
and also um more accurate representation
of the role that that embers play in
producing spot fires. Uh and if you want
I can go into a little bit more detail
about some of the fuels as well.
>> Yeah. Uh, and I think it's it's kind of
important to mention it sounds like when
you were showing us the map, um, the
outline with the bark beetle kill, that
one part of your work that you're doing
is that you're looking kind of after the
fact, right? And then you're kind of
simulating these fires and you're kind
of, it sounds like you're kind of
testing or inputting different variables
to see how you can get that realistic
behavior that you actually observe in
the fire. Is that is that correct to
say?
>> Yes, you you've nailed it exactly.
It's it's fundamental to how we improve
our models. You you have a model that
does some things well. It does other
things not very well and completely
ignores yet more things. And you try
that on data sets that you that you know
and you see how well the model performs
and you you look at what its strengths
are, what its deficiencies are, and then
you make modifications and then you try
it again. And it sounds like I'm just
sort of describing a trial and error
thing, but it's a lot more directed.
It's a lot more um based on fundamental
and applied science than maybe what it
sounds when I describe it that way. But
there's this process of optimization
that has to occur not just with
numerical models really with with
theoretical equations with with a lot of
the basic tools by which science
advances.
Rarely do we come up with the perfect
100% correct answer right away. It's
usually a step forward and you reassess.
You take a few more steps forward, you
reassess. And in the case of fires,
especially the most severe damaging
fires, even though it seems like
during summer, especially hot, dry
summers like this one, they're all
around us.
Each fire is so different from the
others. And there are still relatively
few of them that when new fires come
along, they pose new challenges. We see
things we've not necessarily seen
before. Maybe we suspected it or maybe
we knew knew they took place, but we
didn't have the observations and lo and
behold, there was a new fire this year
or there will be a new fire next year
that is observed better than any other
fire
and we use that then to further advance
our our model. So this is an ongoing
process and um it brings up one really
more important almost philosophical
point about weather modeling, fire
behavior modeling. These models will
always be imperfect
just by nature of the the the chaotic
systems we're dealing with and the fact
that observations are never
um
comprehensive. They're never everywhere
all the time to put it simply.
However, just because these models are
imperfect doesn't mean they're not very
very useful. And in fact, they're
getting better all the time and will
give you very very good answers that you
can base important decisions on, even if
they're not quite perfect answers, and
that's always going to be the case. But
we we make progress by reassessing and
and
applying these models and these other
techniques to known data sets.
>> Great. That's a that's a really good
point. It's just this iterative process
that you know it sounds like sometimes a
fire happens and you you need to really
have it as like almost a case study to
kind of refine your models here. And so
I know you mentioned something about
fuels and some of the work that you and
your colleagues are doing and I think
you mentioned this as a challenge. Uh so
I think this would be a perfect time to
dive in of yeah what uh work you're
doing around these wildfire fuels.
Yeah, I I mentioned that the um it's
important to know what the fuels are,
how much there is, usually that's
measured in mass, for example, and then
how how dry or wet the fuel is. Wetter
fuels do not burn nearly as easily. So,
fires that burn through wet fuels tend
to not burn as quickly. They're not as
hot. uh they produce very different
kinds of smoke because the combustion
when wet fuels burn is not as complete
as the combustion when dry fuels burn.
So understanding specifically the
moisture level in these fuels is is
really important and I have a figure
that I can show you that's that's really
exciting. It's it's um result of work
being led by Pedro Himenez.
And uh
this is a figure, nice colorful figure.
It shows what we call dead fuel moisture
content. That's really how wet is all
the dead stuff on the landscape. pine
needles, twigs, small branches, logs,
all the stuff that's down and on the
ground that used to be living is no
longer living. We refer to these as dead
fuels. And they have a certain moisture
content that is um based partly on how
much it has rained, what the relative
humidity is in the atmosphere, what the
soil moisture is, you know. So these
these fuels can get wetter and drier as
the weather changes. We also talk about
live fuel moisture and that is just the
fuel moisture content of the vegetation
that's still living, the trees that are
still standing, the grass that's still
green.
Getting these observations right is
fundamental to getting fire behavior
modeling right. But it's a very very
difficult thing to do because you have
to take a lot of observations over a
large area and update those observations
frequently. So what we have done the
work that Pedro has led is we use
observations taken on the ground of the
dry and wet and mo and sorry and live um
the dead and live fuel moisture content.
We combined those data with satellite
data both both low earth orbiting and
geostationary satellite data and then
several other data sets that come from
models. We use machine learning and what
we can produce is a map of both the dead
and live fuel moisture content. Again,
this that you're seeing on the screen is
is the dead fuel moisture content that's
updated multiple times a day and covers
all 50 states. I'm just showing the 48
contiguous states, but we have Alaska
and Hawaii as well.
This kind of data set fills in huge
blanks in the areas where we really have
no observations and we have to use what
we call like interpolation. Think of it
as a form of spatial averaging to guess
at what exists between two stations that
are widely separated where you do have
obser obs observations and you don't
necessarily in the middle. Not only does
this data set then when fed into our
models improve the results, but even
without fire behavior modeling, just
access to this kind of data set gives
people a greater awareness of what the
overall fire risk is. So that that's
another area in which we're working.
It's it's more on the land side than the
atmosphere side, but is is vital for
improving our modeling.
>> Great J. Yeah, just really highlighting
the utility of that. Even for someone
who's not in that field, I think you can
really get a sense of the different the
fuel moisture that exists in your area.
So, we've talked about some of the
advancements that we're making um NSFAR
is making here. Um I want to kind of
wrap up some of this conversation with
collaboration. We know that this is
these are chaotic systems, wildfires,
weather and so there are a lot of
stakeholders, a lot of endusers involved
here and I'm just wanting you to speak
because of the laboratory. The research
applications laboratory has a lot of
collaborations. If you can talk about
what you're finding most important, what
collaborations you're finding most
important in this field. I I'm glad you
uh you brought up collaborations going
back to how complex a problem wildfire
is and and how many
sectors and industries
uh are are affected.
It it's both a challenge and an
opportunity. And the opportunity comes
with the collaborations that you're
referring to because it's it's if we
focus on on how to lower the threat of
wildfire in the future and we get people
from different sectors talking to each
other, working together who don't
normally work together. This is hugely
beneficial. So I'll go through a list
like my other lists. This this one is
not exhaustive. Uh first and foremost,
chemists are so important. The single
biggest cost from wildfires cost to
society is because of smoke exposure. We
we know from um fires that we've seen
this year, last year, and years before.
Smoke can go thousands and thousands of
miles away from a fire and infect people
who aren't the slightest bit worried
about the flames themselves, but
nevertheless are exposed to the smoke.
Chemists allow us to understand the
particles, the gases in the smoke, um
how they change with time, what are the
health effects. And so there's another
opportunity for collaboration, people in
the um the healthcare industry. Uh we
work with um people in that sector to
understand
uh the kind of the outcomes um the
threat to health that different kinds of
exposure
um has
people then in other sectors that are
affected by wildfires. think the
transportation industry, you know,
wildfires, especially in mountain
communities where aren't that many roads
in and out of a place, um, can have an
effect. And then in the aftermath of
fires, for years and years afterward,
the landscape has changed.
Glenwood Springs is a good example.
Glenwood Canyon, where where Interstate
70 goes, you know, they've had their
rounds of fires followed by rounds of
debris slides, which interrupts
transportation. The transportation
industry is important. The utility
industry especially uh electrical grid
utilities, they're concerned about
fires, not only, you know,
unintentionally starting fires, but then
also fires that that may be encroaching
on their infrastructure.
foresters, ecologists, soil scientists,
really hot fires, they change the soils
in profound ways such that long after
the the fire is over, uh you you don't
end up getting the same kind of
nutrients, porocity
um in in the soils that that have been
burned. Water quality is an issue. So we
have a group of hydraologists that we
work with here at ENCAR and elsewhere as
well to understand the close
relationship between water and and fire
and there are many close relationships
there other sectors insurance um
national defense you know you can see
it's a long list and I'll stop there but
all these areas they offer these
opportunities for collaboration and
doing science in in kind of new ways
interdisciplinary or sometimes what we
call convergence science science, which
in some ways is the most exciting
science that we're working on.
>> Great. Uh just a reminder for any folks
that want to ask Jason a question to put
that into Slido. Uh Jason, last question
for you here before we jump into our
Q&A. Um if you can may wave your magic
wand here and over like the next decade,
like what advancements do you really
want to see in this space and what role
do you think NSF Encar has to play?
I I would say uh first and foremost
probably better observations of the
atmosphere
and the landscape in the vicinity of of
fires. This has come up before so we're
kind of repeating ourselves here but um
that that's really really important.
Where will those observations come from?
Well, I think we're going to have better
and better satellites up there. Um, more
sophisticated sensors, higher resolution
sensors, and those are a really good way
of observing especially remote areas of
the planet. Drones or uh more generally
what we call uh uncrrewed um aerial
vehicles,
they they will offer opportunities. If
you could imagine having teams deployed
to fires where their sole function is to
fly drones around or take observations
of temperature, humidity, wind, even
what's in the smoke, feed that back to
uh wildfire prediction models. That
would be hugely helpful. So I imagine
we're going to be making a lot of of
progress in that area. couple models
have become more sophisticated because
we'll know more about fire behavior
especially in the built environment and
so the equations in these models that
make the predictions will be better. I
think artificial intelligence really has
a role to play here. AI models are
showing just remarkable
um utility in certain areas uh when
they're relatively young. We've not been
working on artificial intelligence
nearly as long as we've been working on
other models. So this is exciting, but I
think it will be quite some time before
um they can do everything that physical
models do. So in the in the near future,
I think what we're going to see is the
kind of numerical models based on
physics that we've been talking about
combined with artificial intelligence
and that duo that in a way it's a
different sort of coupling that is
probably going to yield some of the most
accurate fire prediction um that we have
workflows will improved. I I would love
to see us get to a point where when you
need a forecast of what a fire is going
to do, you're just a few clicks away on
your computer or your phone the way you
are right now. If you need a forecast of
what the weather is going to do, we've
we've come to know that weather models
are sort of they're operating in the
background at the enterprise level
nationwide
fundamental improvements to to the
accuracy of weather forecasting. I'd
like to see us get to a place where we
sort of consider fire behavior modeling
kind of to be in the same vein and with
a few clicks on my phone I I can see
where a fire is likely to move in 3 6 12
hours. I I think we can get there. It's
sort of a workflow problem. It's sort of
a plumbing what we sometimes casually
call a plumbing problem. We've got the
pieces. Um and then I'd like to see
other kinds of coupled modeling. Imagine
that not only do you have really good
predictions of fire behavior, but we
feed that information into evacuation
models and so emergency responders can
tell people what roads to take outside
of a threatened community. And um and
that's done with input from the
atmospheric modeling, the fire modeling,
the modeling of of how people behave in
these situations, the traffic flow. The
more of these models that we can couple
together and the more that we can
capture the uncertainty that gets passed
from one model to the next, the more we
can make really objective decisions that
that that help people um mitigate the
the threat of fires.
>> Great. Well, thank you Jason for that.
Um on that note, we're going to jump
into our Q&A. We definitely have some
some questions from the audience. But
before that, I want to make a quick plug
just about our upcoming events here. Um
on your screen, you'll see our four
upcoming events from August 26. Uh
that's going to be understanding the
impacts of space weather on satellite
orbits. That's local for folks that are
to Boulder County. That's going to be at
Frraasier.
And then fall in the this Saturday,
we'll have for models forecast tools for
better water operations at the Leland
Museum. And if you are a virtual
audience and can't attend any in person
or just like the comfort of your home,
we do have a hybrid event at the Mesa
Laboratory Cloud Makers: How Alaska
Seasons Paint the Sky. And then lastly,
upcoming on the 19th, we'll be talking
about generally NSF Encar's science
stories and breakthroughs over a 60-year
period at the NOO library in Boulder. So
if folks want to know more about these
events, feel free to take a screenshot
or again search for NSF ENCAR Explorer
series. You can also sign up for our
newsletter. And lastly, I want to make a
plug. At the end of this conversation,
you'll receive an email for an
evaluation survey. Please, if you can
fill that out, it really helps us
understand the outcomes of events like
this, but also you'll be participating
in educational research project. So, you
can also scan the QR code that is on the
screen as well. And so, with that,
Jason, we're going to dive into some of
our Q&A questions here.
Uh, Russ has a interesting question
here. Along the Colorado front range,
Excel has installed many utility pole
mounted remote weather stations. Do the
real-time weather readings from those
stations make their way into some of
these highresolution wildfire forecasts?
Yeah, that's an excellent question. In
some cases, yes, in some cases, no. We
have had really good experiences with um
talking with with uh electric grid
operators, not just in Colorado,
nationwide. In fact, we we've been
regularly attending some of the meetings
that that they hold to discuss for the
entire industry
um h how to deal with fires. they uh
utilities have been some of the the most
ambitious and aggressive about putting
all kinds of weather stations out in
remote places to take observations.
It's it's hugely valuable and and so we
would I I think you know to get more at
this question in the future we would
love to have the answer be universally
yes that all those observations are are
making it into uh models. At this point
it is it depends. The answer is it
depends. It's it's sort of hit or miss.
But what I think what we can say is that
even if some of the models that we're
using here at NSFAR
do not have access to those data, those
data are used by the utilities to make
um really well-informed decisions about
how to manage their systems. And so
going back to the point that wildfire
forecasting takes many forms only one of
which is using coupled models
in a way those observations are
informing the predictions that are made
by the wildfire experts and the
utilities whether or not they're making
it into into our models. But in the
future we'd like to see all of those
data make it in.
>> Speaking of which, we have a question
from Luke about couple models here. How
much more accurate are the coupled
models compared to the up uncoupled
models?
>> It depends on the fire. In the case of
uh heavily wind- driven fires where the
atmospheric environment isn't changing
much. So imagine the extreme case is you
have a violent westerly wind that just
blows steadily during the entire time of
a fire.
you really the the the feedback from the
fire to the atmosphere is it's not zero
but it's relatively small compared to
the role of that wind. So in that
example you would be able to get a
pretty accurate prediction just by
imposing an unchanging
steady wind on the fire and letting it
go and never allowing a fire feedback to
the atmosphere. So that's one kind. At
the other end of the extreme would be uh
a case where almost all the fire
behavior depends on the local
perturbations to the atmosphere because
fires can make their own wind. They make
their updrafts horizontal wind and so if
you don't have a largecale strong wind
that that serves as the environment of a
fire instead you have pretty much calm
conditions imagine and then and then you
have a fire erupt. In that case, the
feedback to the atmosphere is going to
be fairly important because those are
the main changes that the atmosphere
feels. So the the the summary answer to
the question is
what you lose or gain by not coupling or
coupling depends a lot on the specific
fire you're talking about. Sometimes it
doesn't make much of a difference.
Wonderful. We have time for one more
question and I apologize. We had a lot
of questions here. Uh if you don't get
your questions answered, feel free to
email the Explorer Series uh team and we
can get your questions relayed to Jason.
To kind of wrap us up here, Michelle has
a question and a comment here. I really
appreciate you mentioning the benefits
of fire. Do you believe that the
increase in large fast spreading fires
has a connection with the lack of fire
mitigation practices from the 80s to the
early 2000s?
Yes, that there's there's a lot of
evidence um for that. As a matter of
fact, I I mentioned the importance of of
fuels in in understanding fire behavior
and the and the specifically the aspect
of how much fuel is there and that's
exactly what your question is driving
at. there is a lot of fuel to be burned
because really dating back to the early
part of the 20th century 1910 and on.
Uh we've been pretty aggressive about
suppressing fires and you know that was
done based on reasonable understanding
at the time uh among a lot of the
decision makers and it seemed like a a
wellfounded policy. Um, interestingly
enough, Native Americans knew long
before that the importance of having
frequent fires in the landscape. They
they did a lot of their own landscape
management by having prescribed fires.
And so they they often were able to to
keep the amount of fuel load from
building up to the point that when there
is a fire, it is one of these blazing
hot fastmoving fires.
We've we've learned a lot since then. So
if you go back to the early part of the
20th century, really up into probably
the 1960s or 70s,
this really aggressive suppression
policy uh has this unintended consequ
con consequence that the fuel buildup is
massive. And now we're we're kind of
grappling with that. It's the it's it's
one of the reasons that prescribed fire
is important and letting some fires
burn, the good fires burn, because
counterintuitively
by letting those fires happen, we reduce
the risk that future fires are going to
be these hot, really threatening
conflrations.
>> Great. Thank you so much, Jason. And
thank you everyone for joining us today.
We really appreciate it. Again, if your
questions didn't get answered, feel free
to email the Explorer Series team and
we'll get your questions answered. But
with that, we'll see you at the next
event and appreciate your time today.
>> Thanks, Evan.