Weather forecast for the prescribed fire in Arizona that led to accidents on Interstate 40

prescribed fire smoke accidents arizona
Map, produced at 11:41 a.m. MDT Oct. 20, 2016, showing heat detected on the Green Base prescribed fire. The dots nearest the Interstate represent heat that was detected during the afternoon of October 18, 2016. The northernmost dots are from October 17, 2016. Click to enlarge.

We looked further into what led to the smoky conditions that resulted in numerous vehicle crashes on Interstate 40 west of Flagstaff, Arizona early Wednesday morning, October 19. The smoke on the highway from a prescribed fire was referred to as “pea soup”, and was clearly the cause of some of the accidents, but investigators are not yet ready to say the smoke caused the one fatality when a vehicle was sandwiched between two semi trucks.

During the very early morning hours of Wednesday, October 19, smoke settled into the areas around Interstate 40 between Parks and Williams. An electronic sign warned motorists about smoke, but the severely reduced visibility was not anticipated by the U.S. Forest Service. After the accidents started occurring the Interstate was closed for five hours.

ADEQ smoke permit green base prescribed fire
Data from the smoke permit issued by the Arizona Department of Environmental Quality for the Green Base prescribed fire. Click to enlarge.

The Kaibab National Forest ignited the Green Base Prescribed Fire on Tuesday, October 18, 2016 immediately north of Interstate 40. The smoke permit issued by the Arizona Department of Environmental Quality anticipated moderate “impacts on sensitive areas”:

Smoke impacts to the following communities of Flagstaff, Parks, Spring Valley, Pittman Valley, Sherwood Forest Estates and some smoke may impact Williams. I-40 may experience moderate smoke impacts in low-lying areas.

The Flagstaff office of the National Weather Service issued a Spot Weather Forecast for the Green Base Prescribed Fire at 5:28 a.m. MST on Tuesday October 18, 2016. It anticipated a “good” maximum ventilation rate for Tuesday, did not specify one for Tuesday night, and for Wednesday it was described as “fair”.

spot weather green base prescribed fire
Spot Weather forecast for the Green Base Prescribed Fire, October 18, 2016. Click to enlarge.

The ventilation rate provides an estimate of how high and how far smoke will disperse. A high ventilation rate suggests that smoke will spread out quickly and through a deep layer of the atmosphere, so that surface concentrations downwind will be lower than they would be with a lower ventilation rate.

The transport winds (from the ground to the mixing height) for Tuesday night were predicted to be “west 5 to 10 knots shifting to the north after midnight, then shifting to the northeast early in the morning.” The wind speed after the shift was not specified. Perhaps this was interpreted by fire managers to mean it would continue at 5 to 10 knots.

The prescribed fire was just north of the east-west Interstate, so a wind out of the northeast would likely push the smoke toward the highway. And if an area is prone to nighttime inversions, visibility can be compromised.

Fox News reported that Cory Mottice, a National Weather Service meteorologist in Flagstaff, said, “[Smoke] always gets trapped after dark,” he said. “It’s just a question of where the wind blows it.”

However that analysis was not described in detail in the spot weather forecast issued by Mr. Mottice’s office. As in many spot weather forecasts, much of the information appears to be generated by a computer, with little interpretation or discussion about how the information will affect the fire. Meteorologists are not expected to be Fire Behavior Analysts, but sometimes a little human-created discussion and interpretation can add value to a computer product.

Below are excerpts from an article at the Arizona Daily Sun:

… A Highway Patrol captain at the scene said smoke in the area reduced visibility down to about 20 feet, Department of Public Safety spokesman Bart Graves said. Sherwood Forest Estates Fire Chief Wayne Marx said even his crews had to stick their heads out the window to watch the yellow stripe on the road as they escorted commuters away from the interstate.

“You couldn’t see past the end of the hood,” Marx said.


One retired meteorologist who lives in the area believes more precautions should have been taken. Parks resident Byron Peterson, who retired from National Weather Service station in Bellemont, said the smoke was already bad on Old Route 66 Tuesday afternoon. Firefighters waved him on, he said, even though there were times when he could not see 10 feet in front of him.

“It was very frightening to say the least,” Peterson said.

He said strong southwest winds coming up over Bill Williams Mountain near Williams formed an eddy of swirling air that then dove down over the prescribed burn, keeping the smoke from dissipating.

“I tried to explain that to people at the Forest Service and it was just like talking to a wall,” he said.


Interstate highway closed after accidents caused by prescribed fire smoke

Investigators will determine if poor visibility was the cause of a fatal accident.

Above: Vehicles at the scene of an accident on Interstate 40 Wednesday, October 19, 2016. Photo by Arizona Department of Public Safety.

(On October 20 we wrote a follow-up article about this incident which looks at the weather forecast and the smoke permit that preceded ignition of the prescribed fire.)

After numerous accidents occurred in thick smoke from a prescribed fire, authorities closed Interstate 40 west of Flagstaff, Arizona on Wednesday. The Kaibab National Forest conducted the burn Tuesday and knew that a wind shift would push the smoke toward the interstate, but they were surprised that the smoke settled near the ground early Wednesday morning rather than being moved out of the area. Electronic signs warned drivers about the potential hazard.

Below is an excerpt from Fox News:

Multiple collisions with minor injuries to motorists and passengers were blamed on smoky haze that settled over the highway for about five hours. Authorities closed I-40 for hours to prevent more accidents.

Police had not immediately determined whether the poor visibility was the cause of a fatal accident after a vehicle was sandwiched between two tractor-trailers before dawn, said Arizona Department of Public safety spokesman Bart Graves.

But the area at this time of year experiences temperature inversions allowing smoke to be trapped close to the ground and hover over the highway, said Cory Mottice, a National Weather Service meteorologist in Flagstaff.

“It almost always gets trapped after dark,” he said. “It’s just a question of where the wind blows it.”

Forest officials thought weather conditions would vent smoke near the freeway more than it did in low-lying areas, Smith said.

“I believed they used good judgment based on the conditions and the information that they had,” said Brady Smith, a U.S. Forest Service spokesperson.

Rainfall in western states slows wildfire season in many areas

Rainfall last 2 weeks washington oregon
Rainfall last 2 weeks, Washington and Oregon

Rainfall over the last two weeks has slowed or in some cases, ended the wildfire season in some areas.

On October 19 we ran the numbers for the accumulated precipitation for the last 14 days in the western states. These maps show amounts that exceeded 0.05 inches at some of the Interagency Remote Automatic Weather Stations (RAWS).

Washington, Oregon, and northern California have received a good soaking and I would imagine that local fire officials may be declaring an end to the fire season. Of course this is not unusual for these areas this time of the year, and some locations had already seen their season end. But what IS unusual, is the high amount of moisture that occurred in just two weeks.

You can click on the images to see larger versions.

Rainfall last 2 weeks, northern California
Rainfall last 2 weeks, northern California
Rainfall last 2 weeks central California
Rainfall last 2 weeks, central California

Continue to see maps for the other western states.
Continue reading “Rainfall in western states slows wildfire season in many areas”

Update on the condition of the firefighters who deployed fire shelters on the Cedar Fire

(UPDATED at 12:52 p.m. MDT June 30, 2016)

Today the BIA released a “24 Hour Report” about the fire shelter deployment on the Cedar Fire. It provided a few facts that were not previously disclosed by the agency.

The six firefighters deployed their shelters in an area that had already burned, and they were evaluated in the hospital for “smoke inhalation”.

The Serious Accident Investigation Team will be led by Jon Rollins, Chief Investigator for the National Park Service.


(Originally published at 9:52 p.m. MDT, June 29, 2016)

The Bureau of Indian Affairs provided more information today about the six firefighters on the Cedar Fire south of Show Low, Arizona who on June 28 found themselves in a situation where they had to deploy fire shelters. The firefighters, all from the Navajo Interagency Hotshot Crew, walked away from the site and were transported to Summit Healthcare in Show Low where they were treated and released that evening.

A Serious Accident Investigation Team has been formed and will investigate the circumstances surrounding the deployment.

We don’t know why or how the incident occurred, but if recent history holds true, we may never know, thanks to the unintended consequences of Senator Maria Cantwell’s and Representative Doc Hastings’ hastily conceived Public Law 107-203 signed into law in 2002.

But putting aside the unknown details of fire behavior, decisions made on the fireline, and the strategy and tactics being used on the Cedar Fire yesterday, there a few things that we do know.

  • The Type 1 Incident Management Team issued an update titled “Final Cedar Fire Update” on Monday, June 27. It said in part, “While 554 firefighters are working on the fire [Monday] morning, only the Team itself will remain by Tuesday afternoon. The Bureau of Indian Affairs (BIA) will assume command of the fire at 6 A.M. Tuesday.” That Monday update said the fire received rainfall on Sunday and more rain was expected on Monday.
  • The Type 1 Team turned the fire over to the Fort Apache Agency at 6 a.m. on Tuesday, June 28. There was no mention of a Type 2 or Type 3 Incident Management Team.
  • The Fort Apache Agency posted a fire update on Facebook at 1:05 p.m. on Tuesday, June 28 saying the resources on the fire that day were, “Navajo Hotshots, 3 Type 6 Engines, Fort Apache Fuels Type 2 IA Crew.” And, “Fire Personnel will continue to hold and mop up the fire.” These two crews and three engines probably amounted to a maximum of 50 people, plus miscellaneous overhead. This was down from 554 the previous day, a 91 percent reduction in personnel overnight.
  • Candy Lupe, a Public Information Officer with the Bureau of Indian Affairs’ Fort Apache Agency, told Wildfire Today that she was not sure exactly when the incident occurred but estimated it happened around 3 p.m. Arizona time on Tuesday, June 28.
  • The infrared scan of the fire conducted very early Monday morning, June 27, showed “scattered” and “isolated” heat over much of the fire. There was no record of an infrared scan prior to the day shift on Tuesday June 28, but they had been completed every day from June 17 through June 27.

We’re not pointing fingers or attempting to lay blame on anyone. Hopefully the investigation will bring to light some lessons that can be learned.

Carl WilsonThe incident brings to mind the Common Denominators of Fatal and Near-Fatal Fires, developed by Carl Wilson in 1976. Mr. Wilson put two lists together, a four-item list based on his studies of 61 fatal fires, and a five-item list that included an additional 31 near-fatal fires. More information about these lists is in our February 1, 2016 article, Are there 4 or 5 common denominators of fire behavior on fatal fires? Almost all recent wildland fire publications, if they publish the list, only have the four-item list.

These lists are not intended as a quick and easy checklist for investigators, nor are they rules or guidelines that must be followed. They are simply interesting commonalities seen on many fatal and near-fatal fires. Things to think about, not rules that must be adhered to.

Here is the five-item list that includes data from fatal and near-fatal fires:

  1. Most of the incidents occurred on relatively small fires or isolated sectors of larger fires.
  2. Most of the fires were innocent in appearance prior to the “flare-ups” or “blow-ups”. In some cases, the fatalities occurred in the mop-up stage.
  3. Flare-ups occurred in deceptively light fuels.
  4. Fires ran uphill in chimneys, gullies, or on steep slopes.
  5. Suppression tools, such as helicopters or air tankers, can adversely modify fire behavior. (Helicopter and air tanker vortices have been known to cause flare-ups.)”

Cedar Fire near Show Low, Arizona

(UPDATED at 10 a.m. MDT June 24, 2016)

cedar fire helicopter
Helicopter refilling water bucket on Cedar Fire. Undated & uncredited photo from InciWeb.

The Cedar Fire south of Show Low, Arizona continues to spread across the Arizona landscape. The Incident Management Team reports that it has burned 45,918 acres, an increase of about 5,000 acres over the last two days. Firefighters still have miles of open fire perimeter and have been working on constructing firelines and conducting burnouts on the east and west flanks.

Map Cedar Fire
Map of the Cedar Fire perimeter at 9 p.m. MDT June 23, 2016.

SR-60 between Carrizo and Show Low remains closed due to smoke conditions as firefighters actively work near the highway. SR-73 through Whiteriver remains open from Carrizo to Hon-Dah.


(UPDATED at 9:42 a.m. MDT June 22, 2016)

3-D Map Cedar Fire
3-D Map of the Cedar Fire at 10 p.m. MDT June 21, 2016. Looking north.Click to enlarge.

The Cedar Fire south of Show Low Arizona added another 5,000 acres on Tuesday to bring the number acres burned up to 40,340, according to the Southwest Geographic Area Coordination Center. Most of the growth was on the east side, and on the west side near Highway 60.

The southern perimeter is still approximately 1 1⁄2 miles north of Highway 73, and approximately 2 miles north of the Cedar Creek community. The north side of the fire remains fairly quiet.

Map Cedar Fire
The brown shaded areas show the additional growth of the Cedar Fire as of 10 p.m. MDT June 21, 2016. The white line is the perimeter from 24 hours before. Click to enlarge.
Progression map Cedar Fire
Progression map of the Cedar Fire, June 21, 2016. Click to enlarge.


(UPDATED at 8:20 a.m. MDT, June 21, 2016)

map Cedar Fire
The red line was the perimeter of the Cedar Fire at 4:13 a.m. MDT June 21, 2016. The white line was the perimeter from about 24 hours before. Click to enlarge.

The Cedar Fire south of Show Low, Arizona continued to grow substantially on Monday adding another 9,000 acres to bring the total burned area up to about 35,000 acres. The fire was active on the southwest and south sides, but was extremely active on the east side where it spread over two miles further east.

The Incident Management Team (IMT) has posted a video briefing on the fire that was recorded on Monday.

Continue reading “Cedar Fire near Show Low, Arizona”

Satellite photo shows three large columns of smoke in Arizona & New Mexico

Above: map showing three large columns of smoke in Arizona and New Mexico, at 5:15 p.m. MDT, June 15, 2016.

The satellite photo above shows three large columns of smoke in Arizona and New Mexico. We have tentatively identified them, but this is not yet confirmed, as the North Fire (25 miles southwest of Magdalena, NM), the Dog Head Fire (about 25 miles southeast of Albuquerque, NM), and the Cedar Creek Fire, a new fire 12 to 16 miles southwest of Show Low, Arizona.

The North Fire is a limited suppression fire, while the other two are being fully suppressed.

The Cedar Creek Fire started around noon on Wednesday and by 3 p.m. had burned about 1,000 acres. Strong winds were pushing it toward Show Low. Fire officials have identified a trigger point. If the fire reaches the B65 Road they will order evacuations of Show Low and Forestdale.

Earlier today we posted information about six fires in these two states, including the North and Dog Head fires.

Strong winds were predicted for parts of Arizona and New Mexico today, along with a Red Flag Warning for the area southeast of Albuquerque, NM.

wind forecast arizona
The wind gust forecast for 3 p.m. MDT June 16, 2016.

Thanks and a tip of the hat go out to Tom.