A chance to study vortices in a smoke plume

Above: screenshot from the Wall Fire time-lapse video below.

This time-lapse video of the Wall Fire condenses one hour of high intensity fire behavior into a one minute video. It was photographed using the camera system operated by the Nevada Seismological Lab between 7 p.m. and 8 p.m. on July 8, 2017, the day after the fire started. Since then it has burned 5,800 acres and destroyed 41 homes and 55 other structures southeast of Oroville, California.

If you are interested in wildland fire behavior, you may be fascinated by the occasionally counter-rotating as well as single horizontal and vertical vortices as the fire rapidly spreads across the landscape.

This phenomenon is important to firefighters because of the extreme fire behavior that can put personnel in immediate danger.

If you want to read more about horizontal vortices, here are the results of a quick Google search. One of the links leads to an interesting paper titled Three Types of Horizontal Vortices Observed in Wildland Mass and Crown Fires, by Donald A. Haines and Mahlon C. Smith.

Here is a copy of their abstract (click it to see a larger version):

Thanks and a tip of the hat go out to Kelly.
Typos or errors, report them HERE.

Caifornia Fuels and Fire Behavior Advisory

The Southern California Geographic Area Coordination Center has issued a Fuels and Fire Behavior Advisory for the central and southern areas of California due to a heavier than usual grass crop brought on by above average winter rains. Because of the vegetation and climate in Southern California it seems like we hear similar warnings often — heavy rains bring lots of flashy grass fuels, and a dry winter results in low fuel moistures. An average winter can mean typical fire potential, which in this area can still mean large devastating wildfires. But as we often say, the most important factor that affects the number of acres burned is the weather during the fire season.

Below is an excerpt from the Advisory. Following that is the entire document.

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“Due to the heavy winter rains, a significant grass crop has developed across much of California in the recent months. These light, flashy fuels have now cured across most of the southern and central portions of the state, which has led to a significant increase in fire activity across much of the Southern California Geographic Area. Despite the volatility of these grass fires, the heavier fuels are less supportive of fire as moisture levels in the larger diameter materials is near normal for this time of year. In addition, live fuel moisture remains above average in many areas. Therefore, while significant acreage consumption will continue to occur on future fires within the grassy fuel beds, large fires among the heavier fuels are less likely.”

Fuels And Fire Behavior Advisory SoCal

Thanks and a tip of the hat go out to Ken.
Typos or errors, report them HERE.

Live event to discuss wildfire wind tunnel studies

Above: The U.S. Forest Service tests burning pine straw in an IBHS wind tunnel earlier this year. Screen grab from IBHS video.

The Insurance Institute for Business and Home Safety (IBHS) will host a live wildfire-related event on Facebook Wednesday November 9 at 10:30 a.m. EST. They have not provided a ton of information about but it will “open up the curtain a bit on wildfire studies”. (Link to the IBHS Facebook Page.)

Dr. Steve Quaries will discuss the wildfire research that they have been doing in the huge wind tunnel. In 2011 using 105 huge fans and spark-generators, they launched embers at a structure to demonstrate what can happen when a wind-driven fire approaches a poorly prepared structure.

IBHS wind tunnel
The IBHS wind tunnel showing the 105 fans. IBHS photo.

The video below shows embers igniting flammable material on and around a structure in the IBHS wind tunnel.

Earlier this year the U.S. Forest Service used the facility to study the relationship between wildland fire rate of spread and wind speed used in the U.S. wildland fire behavior decision support systems. Previous experiments have been conducted in the Missoula Fire Sciences Laboratory wind tunnel that is more limited in size and wind speed than the IBHS wind tunnel.

This research is a collaborative effort with researchers at UNC Charlotte, University of Maryland, University of Texas Austin, and USDA Forest Service, and is funded by the Joint Fire Science Program.

Fuels and fire behavior advisory for the south

One of the Predictive Services offices, it is unclear which one, distributed this advisory. Our opinion is that when someone provides technical advice, or suggests that others take action or modify their behavior, they should be accountable.


****Predictive Services

Fuels and Fire Behavior Advisory
Southern Area
Southern Appalachian Mountains
October 7-21, 2016

Subject: Increasing Fire Danger in area of Hurricane Matthew subsidence

wildfire fuels advisory

Discussion: An area of exceptional drought with Energy Release Component values above the 90th percentile currently exists over an area covering a large portion of the Southern Area. With the passage of Hurricane Matthew along the east coast relative humidity values are forecast to drop into the teens over this area. There will also be a high likelihood of gusty winds, especially along the western face of the Appalachian Mountains.

Difference from normal conditions: The area of subsidence associated with Hurricane Matthew will exacerbate the already dry environment and move ERC values over a large area above the 97th percentile over the next 10 days.

Concerns to Firefighters and the Public: Any fire in this area will be very resistant to control efforts. Expect complete consumption of fuels down to mineral soil or rock, frequent torching, and increased spotting. Fire intensities will be higher than normal which will likely preclude direct attack of fires. Expect the need for extended mop-up. Expect an increase in long duration fires; with heavy fuels being available to burn and leaves coming off of trees expect a higher than normal probability of re-burn on contained fires.

Mitigation Measures: Do not expect any fire to be routine. Be prepared to utilize indirect tactics with extended mop-up. Utilize aerial supervision to help direct crews and keep them informed on fire behavior. Ensure that LCES is in place before engaging on any fire. Remember to STOP, THINK and TALK before you ACT…actively look for ways to minimize risk to firefighters in what is forecast to be a period of very high fire danger.

Area of Concern: Alabama, Mississippi, Central and north Georgia, Tennessee and the mountain areas of Western South Carolina and North Carolina.

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

Former dispatcher: the training and experience of fire managers no longer relevant

Teepee Springs Fire, 8-29-2015
Teepee Springs Fire, August 29, 2015, as seen from Island Bar in Idaho. InciWeb photo.

Allison Linville, a former aircraft dispatcher for the U.S. Forest Service, wrote an interesting article for High Country News, saying last year’s fires pushed wildland firefighters to the edge.

Below is an excerpt:

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“…In Montana, fire managers were watching fire models and using their extensive training and experience to manage fires just as they always had, only to have people on the ground begging them to understand that they were seeing something totally different. “Their models weren’t showing what a beast it actually was,” said a firefighter on the Flathead National Forest. She was talking about a fire that she barely escaped before it blew up.

It occurred to me last August that wildfires have become qualitatively different. And it was a disturbing thought, the realization that no one had the ability to manage fire anymore. Fire managers can’t understand the fires we have today, because their training and experience are no longer relevant to modern-day fires.

Given the conditions now piling up — hot summers, long fire seasons, low snowpack, heavy fuel loading, an ignorant public, erratic storms — there is simply not enough education or experience available to help teach a fire manager what to do. It’s not the managers’ fault; it’s not any one person’s fault.”