Updated: 5:55 p.m. July 17
First discovered: 50 hours ago, 3:39 p.m. July 15
Initial location: San Diego County, Calif.
Fire type: Wildfire, Type 3
Fire name: Thorn
Thorn Fire initially started 3:39 p.m. July 15 in San Diego County, 5 miles north from Tierra Del Sol.
After being active for two days, it has burned 1,234 acres of private land. A crew of 584 firefighters has been working on site and they managed to contain 75% of the fire as of Friday evening. The cause is still undetermined. The firefighting efforts have incurred $3,151,386 in expenses to date, with the projected final cost amounting to $10,000,000.
The main fuel for the wildfire consists of two-foot brush.
What to expect when two-foot brush is fueling a wildfire
Due to the density and flammability of brush vegetation, brush fires create moderate to high intensity flames. Containment efforts might be challenging, especially in dry and windy conditions, as such wildfire tends to spread rapidly. There’s an increased risk of ember production, which can lead to spot fires as well as brush fuels produce dense smoke.
NIFC Fire Complexity Analysis
This wildfire is considered to be a Type 3 incident. What it means:
• Resources are usually local and some or all of the command and general staff positions may be activated, usually at the division/group supervisor and/or unit leader level. Units may have a predetermined Type 3 organization designated.
• Type 3 organizations manage initial attack fires with a significant number of resources, an extended attack fire until containment/control is achieved or an escaped fire until a Type 1 or 2 team assumes command.
• Initial briefing and closeout are more formal.
• Resources vary from several resources to several task forces/strike teams.
• The incident may be divided into divisions.
• The incident may involve multiple operational periods prior to control, which may require a written Incident Action Plan (IAP).
• A documented operational briefing will be completed for all incoming resources and before each operational period. Refer to Incident Response Pocket Guide for outline.
• Staging areas and a base may be used.
• By completing an Incident Complexity Analysis, a fire manager can assess the hazards and complexities of an incident and determine the specific positions needed (e. G, if sensitive public/media relationships are evident, then an information officer should be ordered as part of the team).
• When using a Type 3 organization or incident command organization, a manager must avoid using them beyond the Type 3 complexity level.
• A Type 3 IC will not serve concurrently as a single
Fire containment
What does it mean for a fire to be 75% contained?
Containment indicates what percentage of the fire perimeter has been surrounded by a control line. In this case, it means that 75% of the wildfire is contained from spreading, while 25% is still uncontrolled.
Containment is part of a larger plan for managing a wildfire. It is normally expressed as a percentage and it refers to how much of the fire perimeter has been surrounded/enclosed by a control line that firefighters create. The containment percentage indicates a certain level of control, but it doesn’t always correlate to safety level. Also, it’s important to note that containment doesn’t mean a fire is out.
How is containment measured?
The incident’s central command constantly receives progress reports from firefighters on the ground. As the fireline is constructed, inspected or reinforced, mappers record those details to adjust the containment percentage. The percentage tells the public how much of the fire perimeter is believed to not go beyond the control lines.
Source: National Interagency Fire Center