CZU, LNU, SCU? How does Cal Fire name wildfires?

How do wildfires get their names?

Clusters of fires are burning in the Bay Area with names like the SCU Lightning Complex Fire and the CZU August Lightning Complex Fire. Cristina Rendon explains how Cal Fire assigns a names to these blazes.

Bay Area residents have been learning a new set of acronyms, like CZU, LNU and SCU, as they track progress against the major wildfires that have taken lives, destroyed homes and consumed huge quantities of acreage since last week.

Many people quickly memorized that the CZU August Lightning Complex Fire threatens towns in San Mateo and Santa Cruz counties. The LNU Lightning Complex Fire stretches across Sonoma, Napa, Solano and other counties north of the Bay Area. The SCU Lightning Complex Fire has become one of the largest in California history by burning portions of Santa Clara, Alameda, Contra Costa, San Joaquin and Stanislaus counties.

Some keeping an eye on the fires have also come to recognize the geographic importance of numerals like 13:4 and 15:10.

But a question that keeps coming up is: what do the names mean?

The alphabet and numeric soup of fire names comes from Cal Fire, which takes the lead in battling most of the state's wildfires.

"All fires get a name. That allows the firefighters that are responding to them to quickly understand where they are going," said Cal Fire's Daniel Berlant in a recent video on social media. "It's up to the dispatcher who is dispatching the fire to assign it a name."

Typically, a single fire gets its name from a 911 dispatcher who takes the first emergency call about a blaze. A fire reported near Main Street would probably be named the Main Fire, Berlant said, while reports of flames near June Lake might start a file about the June Fire or Lake Fire.

But the recent lightning strikes that ignited 560 fires across California led Cal Fire to use some of its other naming guidelines when there's a cluster of many fires in an area.

The complex in the name means that firefighters are dealing with multiple nearby blazes.

The three letters at the beginning of the name indicates which Cal Fire unit is in charge of the response. The LNU complex is for the Sonoma Lake Napa Unit, which actually extends also into Solano and Yolo counties. CZU is for the San Mateo and Santa Cruz Unit while SCU stands for the Santa Clara Unit, which, despite its name, additionally includes Alameda and Contra Costa as well parts of other counties to the east.

"Operationally it's more efficient for us to manage these fires under one command," Berlant said in the video.

Because there are multiple small fires grouped together in these complex fires, it may be impractical for dispatchers to use streets and landmarks as the name for individual fires. In those cases, the individual fires are numbered.

"While many of the fires get names, the sheer number of them require us to go to a numbering system," Berlant said.

Within the LNU group, are the 15:10 and 13:4 fires. The first number corresponds to the battalion within the LNU unit that is responding to the fire. The second number indicates "the sequential order in which it occurs,' Berlant said. In other words, 13:4 means that Battalion 13 in the LNU Unit is responding to its fourth fire.

"I know it can be complex," Berlant said in the video, "but there is a reason for it, so that we operationally can manager these fires as our goal is to contain them as quickly as possible."