More information is coming to light about the events that led up to the ignition and later escape of the planned 100-acre Davis prescribed fire on the Helena National Forest that so far has burned 2,181 acres and required the evacuation of about two dozen homes. About 1,000 acres of private land has also burned.
Montana State University’s Fire Services Training School distributes an electronic newsletter five days a week, covering news items about all aspects of fire, including wildfire. It is also available on their web site a number of days after the emailed version is broadcast. The newsletter, widely distributed and praised, is called The Latest and is free to Montana residents; non-residents are charged a fee. It’s probably safe to assume that there are hundreds of people, if not thousands, on their daily distribution list.
Today’s edition of The Latest included copies of emails written by Amber Kamps, the District Ranger for the Lincoln Ranger District where the escape occurred, as well as one by a local fire chief. Portions of those emails are in the time line below.
Here is the sequence of events related to the Davis prescribed fire, beginning the day before ignition.
Tuesday, August 24 —
The National Weather Service issues a Fire Weather Watch for Thursday, effective from noon to midnight.
District Ranger Amber Kamps meets with her staff. They discuss the objectives for the prescribed fire and whether the weather would be appropriate.
An employee of the Forest Service calls a local fire chief to inform him about the Davis prescribed fire planned for the next day. The fire chief then sent an email to his colleagues to let them know about the prescribed fire:
..[the prescribed fire will start tomorrow] with black lining tomorrow and the burn starting thereafter. The burn should take about 3 days.
I told [the Forest Service employee] about the Fire Weather Watch issued for Thursday at noon to midnight for all our local zones. He said they were still evaluating the parameters and would only start the operation once everything was in place. Just thought you would all like to know where the smoke was coming from.
Wednesday, August 25 —
The USFS ignites the 100-acre prescribed fire. There was at least one spot fire, and it burned an additional 20 acres outside the project boundary.
In the afternoon or evening the National Weather Service upgrades the Fire Weather Watch to a Red Flag Warning effective for the afternoon of the next day, Thursday.
Thursday, August 26 —
District Ranger Amber Kamps sends an email about the project, thanking those who helped, and going into some detail about the prescribed fire. We don’t have a time stamp for the email, but it obviously was sent before the fire escaped around noon or 1 p.m. Here are some excerpts:
Subject: Davis Prescribed Fire
Thank you to all the fire folks on both Forests for lending a hand in helping us apply prescribed fire yesterday. It was a good day – we met objectives both for the resource and in safety.
I thought I’d address a few questions that did come up yesterday internally and externally.
Acres: achieved about 100 – 120 acres of fire within the 530 acre unit, 200 acres of the parks/grass were burned this past spring = approximately 300 acres of total treatment
Today’s goal: holding and applying lots of water to cool it down, we have hose lay around the majority of the burn and have plenty of resources such as a 20 person crew, engines, tenders, and a helicopter
Yesterday a large column of smoke was created and very visible from Helena. The smoke was very black as well, which we suspect is due to the mountain pine beetle killed lodgepole combined with the subalpine fir. We also had a spot fire that eventually tied into the unit. The spot or “slopover” also achieved objectives and nicely has tied together two open parks.
Yesterday a Red Flag Warning was issued in the afternoon. Many questions arose as to why we’d be burning under these conditions. However, people need to know we had done careful planning with the National Weather Service and spot weather forecasts. Conditions on the burn were 70 degree temperatures, humidities over 20%, and winds less than 10 mph – right in prescription. We know today is critical for holding given the passage of a cold front predicted for this afternoon. As you know, it is not “normal” to be burning in August and we wouldn’t be if it wasn’t for this strange summer opening up a burning window earlier than it usually does.
Even though we know yesterday was a success in achieving objectives, we also learned a lot and were challenged given the conditions as a result of the mountain pine beetle caused mortality. We have more of these types of burns planned and more upcoming with expectations established under the Southwestern Crown. We will keep learning, adapting, and applying as we move forward.
As people are reading her email, multiple spot fire are occurring or being discovered — more than the firefighters can handle. At 1 p.m. it is declared an escaped prescribed fire. From Helenair.com:
Greg Archie, who works for the state Department of Natural Resources and Conservation, is the incident commander for what’s now being called the Davis fire. He was helping the Forest Service with the prescribed burn Wednesday, and said that when they returned on Thursday morning, he brought “65 people to deal with that 20 acres.” They also had nine engines, three water tenders and a helicopter as they started the day.
“We were making pretty good headway collecting all the spots, controlling the 20-acre slop-over, when a spot came up that we hadn’t had any people on and were not aware of,” Archie said. “Once it got going and started to branch out in the subalpine fir, it’s pretty alarming in the way it can spread.”
The prescribed burn turned into a wildfire by 1 p.m. in the upper portion of Gould Creek, growing from 20 to 100 acres in an hour. Archie said they couldn’t safely put people on it, so they called for an air tanker and retardant, as well as other resources. By 8 p.m. the Davis fire was estimated to cover 2,800 acres [later mapped at about 2,100 acres].
Confusion about the weather forecasts
During the formal investigation of the events surrounding the escape of the Davis prescribed fire, there will be a lot of scrutiny of the weather, the weather forecasts, and the requests for spot weather forecasts which are written specifically for the area of the fire. From our analysis of the spot weather forecasts available on the National Weather Service web sites, it appears that while two spots were requested on both Tuesday and Wednesday, August 24 and 25, it appears that the forecasts they received on Tuesday did not specifically, or at least clearly, provide detailed forecast information for Wednesday, the day the prescribed fire began.
But, the forecast the fire managers requested at 10:16 a.m on Wednesday did have a detailed forecast for Wednesday, Wednesday night, and Thursday.
Weather forecasts requested on Tuesday:
The District Ranger said they obtained a spot weather forecast from the National Weather Service on Tuesday. While the list of spot forecasts for Tuesday August 24 does not show any for the Davis fire, apparently two were issued, and show up on the lists for August 25 and August 26. It appears that the NWS lists them on the days when ignition was planned, rather than the date the forecasts were requested or issued…unless you want to be a conspiracy theorist and think they were written after the fact and back-dated.
The two spot forecasts requested on August 24 were issued 35 minutes apart, according to the data at the top of each of the forecasts. The predicted weather for the two is significantly different, possibly because the first request included weather observations, while the second did not. Knowing what the actual conditions are at the site can make it possible to provide a more accurate forecast. Unfortunately, the names of the NWS meteorologists who developed the forecasts are not identified on either of them.
The first forecast was requested at 1:59 p.m. and was “based on an ignition time of 10:00 MDT on August 26”, Thursday. It said a fire weather watch was in effect for Thursday afternoon, for very warm temperatures and gusty southwest winds along with the passage of a cold front. But while it had a detailed forecast for Thursday August 26, there was no forecast for Wednesday, the day the USFS ignited the prescribed fire.
The forecast requested at 2:34 also mentioned the fire weather watch for Thursday. The forecast was “based on an ignition time of 10:00 a.m. on Wednesday, August 25”. It had a “discussion” that mentioned “light terrain driven winds on steeper slopes”, and it had detailed forecasts for “today” and “tonight”, but does not clearly have a forecast for Wednesday. Since the forecast was written on Tuesday, August 24, a person would assume that a forecast for “today” and “tonight” referred to Tuesday.
Weather forecasts requested on Wednesday:
The Forest Service said they obtained a spot weather forecast on Wednesday. The NWS site lists two spot weather forecasts that were requested on Wednesday, one at 10:16 a.m and another at 7:51 p.m. The list of spot forecasts on the NWS site for Aug. 25 lists three, but one of them was supposedly requested August 24 and was the forecast for August 24, but it proposed an ignition date of August 25.
The 10:16 a.m. forecast predicted a minimum relative humidity of 18-23% on Wednesday with wind gusts at 20 to 25 mph by the afternoon. For Thursday, the forecast included wind gusts to 40 mph by late afternoon with an RH of 10-15% .
The red flag warning was first mentioned in the 7:51 p.m. spot weather forecast, which also said the winds late in the afternoon on Thursday would gust up to 30 mph, and the minimum humidity would be 9-14%.
Weather forecast requested on Thursday:
One spot weather forecast was requested on Thursday, at 5:56 p.m. after the fire was declared a wildfire at 1:00 p.m. The forecast said the red flag warning would be in effect until midnight, for very low humidity, winds gusting up to 45 mph in exposed locations, and possible isolated thunderstorms with variable and erratic winds near the fire area.