From the Cliff Mass Weather Blog
Cliff Mass
During the past six months, research scientist David Ovens and I have worked intensively on the meteorology of the August 2023 Maui wildfires and have completed a paper that was accepted in an American Meteorological Society journal with a few revisions.
This blog will describe our results, some of which provide different conclusions than those discussed in many media accounts.
The City of Lahaina with the West Maui Mountains to the east before the fire.To start, it is important to note that there were multiple fires on August 8-9, 2023 (see map below). On Maui, Lahaina was destroyed by one fire and there were large fires in the generally rural area of central Maui. Substantial fires also occurred over the Kohala area of northwest Hawaii.
The August 2023 wildfires were associated with strong, dry downslope winds gusting to 60-80 mph.
But why did it happen?
An unusually strong high-pressure area developed to the north of Hawaii (see map below), which resulted in very strong northeasterly trade winds approaching the West Maui (and other) mountains.
Importantly, the subtropical inversion, a stable layer often evident over Hawaii, was unusually low (because of the high pressure).
The strong trade winds and inversion were optimally positioned to produce a high amplitude mountain wave downstream of the West Maui mountains, a wave that resulted in intense and very dry downslope winds on the west slopes of the terrain (see cross section of winds and temperature for northwest Maui, below).
The winds that descended into Lahaina and initiated and spread the fire.
Look closely at the above figure and you can see a hydraulic jump structure, not unlike the situation accompanying water descending a dam ( see below).
This structure was even evident in the clouds and smoke the day of the Lahaina fire (see below)
One of the most amazing aspects of this event was that it was forecast nearly perfectly DAYS before by operational models and certainly by the research model I am using (WRF).
Below are the predicted surface winds on Maui for a short (17-h) forecast, as well as predictions 41, 89, and 137 hours in advance. All are similar and very accurate. The star shows the position of Lahaina; red and brown show the strongest winds.
The National Weather Service HRRR model was similarly accurate. There was no excuse for not warning the population of a terrible threat.
There was a lot of talk about the role of Hurricane Dora, which passed about 800 miles to the south of Hawaii (see satellite imagery below). Many media outlets and some politicians blamed the strong winds on Dora.
But is this true? The wind circulation of the storm was not large in scale, so the direct winds of Dora would not be a factor, but what about indirect effects?
David Ovens and I came up with a way to determine Dora’s impact with some confidence.
We started with an excellent 6.5-day forecast of the Maui winds and the hurricane. Then we weakened the storm by slightly cooling the surface around the storm. Hurricanes are VERY sensitive to the temperature of the sea surface and require sea surface temperatures of at least 80F.
The result was a profoundly weakened storm (see the difference below for the flow around 5000 ft (850 hPa)
And now the exciting part. The winds with the weakened (attenuated) storm were essentially the same as the full throttle beast (see below).
Hurricane Dora played little role in the Maui wildfire disaster.
Finally, there was a lot of talk about the Maui fires being the result of drought and climate change, particularly from Hawaiian politicians, the power company whose lines failed. and some advocacy groups.
So we checked out the conditions before the fire. Turned out that precipitation around Lahaina was above normal BOTH for the summer and the previous year (see below)
And temperatures were near normal (not shown here, but in the paper). Ironically, the heavy rain contributed to the fires by increasing the amount of grass upwind of Lahaina.
In short, climate change or drought had little to do with this event.
The Bottom Line
Lahaina was a disaster ready to happen. A human-caused disaster. Large areas of highly flammable invasive grasses were just east of Lahaina. Grasses growing in abandoned farmland.
The power infrastructure was poor and prone to wind damage.
The National Weather Service and local agencies did not make the best use of greatly improved weather forecast models.
Warnings were inadequate, and roads were blocked by powerline crews and fallen poles/lines.
But the weather forecasts were stunningly good. We have come a long, long way.
Hopefully, our paper and future work will contribute to ensuring this terrible tragedy never happens again.
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GREAT WORK CLIFF!
Firefighters thought they’d put out the invasive grass fires east of Lahaina, so left the area, but the forecast high winds reignited them.
Had the fire department heeded the weather service warnings, they’d have left watchers, rigs and crews.
Distressingly similar to the fires associated with the Santa Ana winds in SoCal.
Cliff mentioned the short term preventative measures which start with paying attention to weather forecasts, especially forecasts for hot dry winds. De-energizing power lines based on the forecast would have helped. A longer term preventative measure is controlling fire prone vegetation, several cities in SoCal (e.g. Thousand Oaks) have weed abatement programs to reduce damage from fires.
Roundup the invasive grasses and plant native vegetation on the abandoned farmland.
Or start using the farmland again !!
Grazing is a quite effective way to keep grass fuel loads down.
Prescribed grazing with goats works amazingly well on cheat grass
which is very flammable not familiar with the type of grass on HI.
Goats are browsers by preference, but will eat whatever is available. Tin cans may have been an exaggeration.
Sheep are grazers by preference, but do tend to be more fussy. They also have an amazing ability to find novel ways to die.
Just as long as he state doesn’t require the herders to join a union…
I think goats may be a better choice for grazing as the ideal situation is to remove most of vegetable matter above the soil surface, but keeping the roots in the ground for soil stability in rainstorms and windstorms.
Re-establishing agriculture would likely reduce fire hazard as well.
But, But … surely that will mean growing food! Isn’t that something being banned currently by the Climate Alarmist zealots?
Wilding, as it is euphemistically referred to will guarantee wild fires become ever more prevalent. As the fuel to start and sustain them grows literally uncontrolled, what else can possibly happen?
The societies in and around such mandated uncontrolled growth of vegetation will be subject to devastating ‘wild’ (or should that be wilding?) fires every few years.
The Alarmist champions, will then be applauded for telling everyone wild fires are increasing and it is all due to human induced Climate Change, just as they had predicted.
What was that Bono character’s first name again?
We call them National Parks.
How many children died in the fire? How many people total? What do the locals say?
How many non-existent welfare children disappeared … never to be seen again.
(I have a hard time thinking 2,000 kids actually were lost)
Story tip
Police arrest Jaguar I-Pace driver, 31, on suspicion of dangerous driving after ‘out-of-control’ car had to be rammed off the road by officers when it ‘went rogue’ at speeds of up to 100mph…
‘An investigation, supported by the Driver and Vehicle Standards Agency (DVSA), is underway and a 31-year-old man from Bolton has been arrested on suspicion of dangerous driving and causing a public nuisance.
‘He has been taken into police custody to be questioned.’
https://www.dailymail.co.uk/news/article-13192851/Police-arrest-Jaguar-Pace-driver-31-suspicion-dangerous-driving-control-car-rammed-road-officers-went-rogue-speeds-120mph.html
If crazy UK police stories that are true is of interest you? Check out the one about police stopping a BMW X5 towing a stolen caravan down the MI motorway. There for some unexplained reason the police decided to involve themselves following the report of a caravan being stolen ( I know unbelievable but it happened apparently) anyway they located the stolen caravan and stopped the driver on the motorway. The driver turned out to be an eleven year old boy, he was driving a stolen BMW X5, displaying cloned number plates belonging to a legitimate BMW X5. The police took the child into custody then released him.
No further news is coming out about the incident.
No prizes for guessing what community group the child belonged to.
The police of interest to me?
You’ve confused me with someone else – I wouldn’t trust them – ever.
… and one of the basic examples of western corruption that Cy Qtub gave when he created the muslim brotherhood was that we mowed our lawns regularly…
Article says:” The winds that descended into Lahaina and initiated and spread the fire.”
I understand the spreading, but how can wind initiate a fire.
Knock down a tree into a powerline?
Ok, but which started the fire the wind or the power line and if power shut off no fire.
All that wind caused two sticks to rub together?
Pele is God of Fire & Volcanoes. Fire first.
We, the non-initiated and only casually familiar with the Aloha Spirit and other over-riding Hawaiian values often fail to recognize that Pele is more than just a Volcano Gal. She is God of Fire … the fact that she lives in a volcano may confuse those of us not in tune with the Spirit.
Paka’a is he who controls the wind and gales. Being the bastard son of a king and a commoner he is not really a god. He inherits his power from his mothers (and her mother before her) gourd so he is not a major God, and I would argue that he is not really any type of god at all; seems to me that he is more of a very gifted and capable shaman that needs the magical tool that is the wind gourd … without which, his efforts would be limited to farts and burps.
It is up for discussion as to weather Pele or Paka’a should be considered the most responsible. But to initiate fire does seem to be the sole province of Pele.
As usual, climate change is blamed so the “authorities” don’t have to take responsibility for bad management.
Cliff M. was on this from day one, and I regularly read his blog posts. Now he has a fully developed explanation of the weather for that day. Published too! Gold Star.
People, who shouldn’t have, ignored the growing threat and then during the event made bad decisions. In Cliff’s home State of Washington where similar threats of serious fires exist, several actions are in place to contain the damage of fires — Fire Adapted Communities (FAC) and Firewise USA are two of the formal efforts. There are others.
I’m not sure how you can assert this so confidently after acknowledging that “an unusually strong high-pressure area developed to the north of Hawaii (see map below), which resulted in very strong northeasterly trade winds approaching the West Maui (and other) mountains.” Which are features that climate change is expected to exacerbate.
You also deny that drought had anything to do with the fires, citing precipitation statistics for the summer and previous year, despite the fact that most of the island was experiencing abnormally dry to severe drought conditions at the time of the fires:
This seems like a drastic omission on your part.
The rest of your analysis seems sound – no one has ever claimed that the fires could not have happened without climate change, just that climate change can and will exacerbate conditions that led to the fires.
Because that is a weather pattern well known to meteorologists familiar with Hawaii? It’s happened many times before and will no doubt continue to do so without help or hindrance from anything else. This instance was slightly different from previous ones in that there was a perfect storm of the downslope winds to spread the fires, the fuel (dead invasive grasses) and the poor state of the power infrastructure to initiate the fires.
If you cannot understand what is written in the posts (and it certainly seems that way from what you’ve written) then ask an adult to help you with the big words.
The claim scientists are making is simply that the confluence of factors leading to the fires, which you acknowledge were unusual, are predicted to become increasingly less unusual under global warming.
We can predict more calamity, destruction, and death due to “progressive’s” policies.
So what are you saying? Power lines will become more fragile and prone to sparking? That’s a remarkable claim to make for climate change.
Cliff is correct, drought doesn’t matter much in the conditions that led to the fire. As Cliff and others have said, grass only needs a few hours of hot dry winds to turn into fuel.
It’s not a binary – grass isn’t just “fuel” or “not fuel.” The drier it is the better it burns, and it gets drier the longer drought conditions persist. Cliff does not even claim this, nowhere in the above article is it stated that drought does not contribute to wildfires, Cliff actually tries to imply that drought conditions were not present at the time of the fires.
Cliff is still correct in asserting that there was no long term drought, which have meant there would have been less grass to burn on top of the that even wet grass will rapidly (matter of a few hours) dry out in those wind conditions. The really big fires associated with Santa Ana winds usually occur after a very wet rain season. The conditions for the Lahaina fire were almost exactly the same conditions for numerous wildfires in Southern California that I’ve witnessed over the last several decades.
I’m very impressed with Cliff’s understanding of fire weather, and his recommendations on what needs to be done to reduce fire danger.
Yes. We never had the problem of too much grass in a drought.
In practice, reduced rainfall leads to reduced growth, rather than the grass drying out more quickly than it would under the same short term weather conditions.
There is the rain season and the dry season. Every year there is growth that dies and dries … and will burn … and will burn very hot given high fuel (wind) conditions. Yes, alan, oxygen is part of the fuel.
Trying to define the dry season as drought is asinine.
of course, no one is doing this.
“The drier it is the better it burns, and it gets drier the longer drought conditions persist.”
No, it gets dry during the dry season … and it doesn’t get any dryer.
Then it gets wet and the vegetation grow again. Sometimes lots of grass, sometimes not so much. Then the grass dies, dries, and rots the following season, or burns.
It loses its moisture content in the dry season. Doesn’t matter if there is a defined drought, or not.
Very nice Cliff.
Having asphalt roof shingles didn’t help.
Have a look at “Lahaina Miracle House” to see why it didn’t burn unlike its neighbours.
It’s the ember wash that ignites most homes in a wildfire. Small things like
putting fine stainless screens on roof vents, using cement fiber soffits & siding and putting the
screened vent holes away from the wall and down near the facia can save a home.
I have a modified WEEDS system on my house with rooftop sprinklers and keep the perimeter clean foam system for the windows a generator driven well pump with a gas pump at the beaver pond
below the house….wildfire sprinklers are #1..asphalt shingles can have a class A high fire rating…
Hope I never have to use it..
Jack Cohen’s Utube video . is pretty good.
Your Home Can Survive a Wildfire
https://www.youtube.com/watch?v=vL_syp1ZScM