Cal Fire Expects Fire Conditions to Worsen in LA

LOSANGELES -- The Palisades Fire, which has destroyed more than 5,000 structures since Tuesday, continues to be flamed by wind gusts up to 40 mph with conditions not expected to improve soon, said CalFire.

On Saturday, typical mid-January conditions are expected, and continuing through the middle of next week, weak to moderate Santa Ana winds are expected. There is a chance of strong winds Tuesday, and there will continue to be a high likelihood of critical fire weather conditions through next week.

The Los Angeles County and CAL FIRE Damage Assessment Teams (DINS) continues to assess and validate structures impacted by the Palisades Fire, and said, more than 5,000 structures have been destroyed.

The Los Angeles Unified School District has canceled classes for all schools Friday. Residents are encouraged to avoid nonessential travel to allow firefighters plenty of room to work.

Some may need to manage an evacuation. Consider the following:
Managing an evacuation shelter involves providing a safe place for people who are displaced or in danger. Evacuation shelters are typically used for a short time, such as during a storm.

Planning

• Create an evacuation plan: Consider how to evaluate the emergency, identify safe areas, and assign responsibilities.
• Practice: Conduct training exercises and review the plan regularly.
• Prepare: Make a home inventory, gather important documents, and plan what to bring.

Sheltering

• Find a safe place: Go to an interior room with few windows.
• Seal openings: Use thick plastic sheeting and duct tape to seal doors, windows, and air vents.
• Bring supplies: Bring your emergency supply kit, including food, water, and medications.
• Stay informed: Listen to local media for official news and instructions.

A wildfire disaster resulting in the loss of homes and lives is almost always the result of worst-case scenario conditions. This includes severe weather (hot, dry, and windy), topographical conditions (steep slopes) and ample fuel (living and dead vegetation), that carry fire quickly.

These conditions allow wildfire to spread rapidly and build in in intensity. As the intensifying fire spreads, homes become an additional fuel source and simultaneous ignitions can occur; in many instances, burning homes ignite other homes.

Firefighter response can be quickly overwhelmed due to limited equipment, personnel, and water. Fire protection effectiveness is also reduced when firefighters must use their available resources to extinguish or contain structure fires.

Temperature, humidity, precipitation and wind are all important weather variables that influence the intensity and spread of fire. For example, during hot and dry weather vegetation can dry out quicker and ignite easier.

Wind increases the supply of oxygen to a fire and causes pre-heating of fuels in front of the fire, which dries vegetation and speeds up the rate of spread.

Topography also affects fire behavior. Steep slopes carry fire uphill at an increased rate.

Topography also affects fire behavior. Steep slopes carry fire uphill at an increased rate of spread, while canyons can act as channels for wind to spread fire. Slope orientation plays a role as well.

For example, slopes that face south or southwest have greater exposure to afternoon sun, resulting in lower humidity and higher temperatures. While we can’t change topography, being aware of how it influences fire spread is important.

Residents can influence fire behavior by thinning trees and shrubs, pruning lower branches, removing flammable plants that are in close proximity to the home, and creating fire breaks with features such as walking paths or driveways. These actions decrease available fuels.

Flammability depends on size, density, moisture content, and chemical properties (some plants ignite faster and burn more readily than others).

Fuel classifications include:
• Fine fuels like grasses and needles ignite easily and burn quickly, these fuels tend to carry and spread the fire.
• Ladder fuels are typically shrubs or small trees. They help carry the fire from the surface up to the tops of trees.
• Heavy fuels, like trees, large limbs, downed logs, large shrubs, homes and outbuildings require more energy to ignite, but burn longer and produce more heat. They tend to loft more embers into the air.

Of the three fire behavior factors, fuel is where residents can affect the greatest change.

For more, go to fire.ca.gov and nfpa.org.