Map of the French Fire. The black line was the perimeter determined by a fixed wind mapping flight at 8 p.m. PDT August 22, 2021. The red dots represent heat detected by a satellite at 3:51 a.m. PDT August 23, 2021. The dark red areas had intense heat during the mapping flight. Green indicates Sequoia National Forest.
From the French Fire Incident Management Team at about 10:30 a.m. Monday:
“On Sunday, Aug. 22, fire crews constructed a handline near Wagy Flat Road (Forest Road No. 25S02) to hold the fire and connect into a previous controlled line. Crews were also successful continuing handline from the Sawmill Road break to the division break that is one mile south of Wagy Flat.
“Today [Monday] crews will continue to mop up in those areas and pay close attention to the structures off the Sawmill Road. Further west, towards Rancheria Road (Forest Road No. 25S15), there was some fire growth and fire crews successfully used dozers and hand crews to catch the smaller spot fire that slopped over onto Borderline Road. Crews will work towards Rancheria Road constructing direct line with a strong probability they can get up to Rancheria Road within the upcoming days.”
12:03 p.m. PDT August 22, 2021
French Fire map. The black line was the perimeter determined by a fixed wing mapping flight at 8:32 p.m. PDT August 21, 2021. The red dots represent heat detected by a satellite at 2:32 a.m. PDT August 22, 2021. The dark red areas had intense heat during the mapping flight.
On Saturday the French Fire west of Isabella Lake in Southern California exhibited group torching of trees and long-range spotting, but the activity slowed during the night. The blaze has burned 13,341 acres.
For Sunday firefighters are concerned about the spot fire west of Alta Sierra which is a threat for the residences in that area.
Additional spread is possible with upslope runs and long range spotting to the east.
To see all articles on Wildfire Today about the French Fire, including the most recent, click HERE.
The weather forecast for Sunday calls for 2 to 6 mph winds out of the northwest, 77 degrees, and 40 percent relative humidity. Slightly stronger winds are expected on Monday with lower humidity.
Crews have confirmed that eight residences have been destroyed.
Evacuations are still in effect. The county has developed a map showing the areas affected.
The 104,000-acre fire is 14 miles southwest of Lake Tahoe
Updated 10:09 a.m. PDT August 23, 2021
Caldor Fire map. The black line was the perimeter during a mapping flight at 5:25 p.m. PDT Aug. 22, 2021. The interior blue line was the perimeter about 18 hours before. The red dots represent heat detected by a satellite at 3:51 a.m. PDT Aug 23, 2021.
The Caldor Fire in northern California 14 miles southwest of Lake Tahoe did not spread as much Sunday as it did Saturday when it ran four miles to the northeast. Still, it added about 6,000 acres to bring the total up to 104,309 acres.
Most of the growth Sunday was on the northeast side near Kyburz, on both sides of Highway 50 where spot fires occurred up to a half-mile ahead of the main fire front. A spot fire north of the highway south of Granite Springs Road grew substantially. Under the existing conditions of weather and fuel moisture, burning embers lofted into the air easily ignite the very dry fuels.
To see all articles on Wildfire Today about the Caldor Fire, including the most recent, click HERE.
On Monday firefighters expect southwest winds to continue, with ridgeline winds of 4-9 mph. Fire growth will occur in all areas, especially on the north and northeast flanks. A minimal inversion and smoke layer should clear before noon, with fire activity increasing quickly, aided by the up-canyon breezes. Smoldering spot fires will begin to become active once exposed to the wind and sunny conditions. New spot fires could occur up to a mile ahead of the main fire front.
Diurnal wind patterns will likely cause the Caldor Fire to send smoke into the Lake Tahoe Basin during the day. After sunset a down canyon flow will cause smoke to drain down the Highway 50 corridor into Placerville and the Eldorado hills overnight.
Night flying helicopters are being used to drop water at night for the first time in Northern California. On August 18 a group of three large helicopters that can carry 1,000 to 3,000 gallons was dispatched to the area from the southern part of the state. Since arriving they have been stymied by visibility problems caused by smoke trapped in inversions, but at least one was flying Sunday night. The video below shows the smallest of the three large ships, a 1,000-gallon Sikorsky S-61, dropping on the Caldor Fire. The other two are 3,000-gallon CH-47D Chinooks.
Due to extreme fire conditions and “strained firefighter resources throughout the country” the US Forest Service has enacted a temporary closure of nine National Forests in California: Tahoe, Plumas, Lassen, Mendocino, Klamath, Six Rivers, Shasta-Trinity, Modoc, and Lake Tahoe Basin Management Unit.
9:05 a.m. PDT August 22, 2021
Caldor Fire map. The black line was the perimeter during a mapping flight at 9:15 p.m. PDT Aug. 21, 2021. The green line was the perimeter about 24 hours before. The red dots represent heat detected by a satellite at 2:30 a.m. PDT August 22, 2021. The dark red areas had extreme heat during the last mapping flight.
The northeast side of the Caldor Fire ran for more than four miles Saturday, growing to 98,000 acres while being pushed by 8 to 10 mph winds out of the southwest gusting to 20 mph. The relative humidity measured at the Barney Ridge weather station south of the fire on Omo Ranch Road never dropped below 30 percent, which likely moderated the spread.
The fire activity slowed Saturday night as the wind decreased but spot fires were still occurring.
The weather forecast for Sunday is for high temperatures in the 70s, relative humidity 25 to 32 percent, and afternoon winds becoming southwest at 5 to 9 mph with 15 mph gusts.
The fire is along Highway 50, 14 miles southwest of Lake Tahoe and 36 miles east of the Sacramento suburbs.
During a fixed wing mapping flight at 9:15 Saturday night the Caldor Fire was less than a mile from Highway 50 in several places, but was still mostly south of the highway. A significant spot fire had become established north of the road near Kyburz.
Caldor Fire vicinity map, 9:15 p.m. PDT Aug 21, 2021.
As it spread over four miles Saturday there were numerous spot fires caused by lofted burning embers out ahead of the fire. One of the spots southwest of Sciots Camp was was documented 1.8 miles from the main front.
Firefighters expect the growth to continue Sunday in all areas, with minimal growth at the southern and eastern portions, and major growth continuing on the north and northeastern sides. Spot fires will occur a half mile ahead. The Probability of Ignition will be 87 percent, meaning 87 percent of lofted firebrands that land in receptive fuels will ignite the fuel. The wind may clear much of the smoke out making it possible for air tankers and helicopters to assist firefighters, but they may be limited or ineffective due to the wind speeds.
Officials reported that 235 residences have been destroyed, an increase of 56 from yesterday.
Resources assigned to the fire Saturday evening included 28 hand crews, 194 fire engines, 22 dozers, 15 water tenders, and 20 helicopters for a total of 1,603 personnel.
Nationally, 26,123 personnel are working on wildfires today. Six of the eight military C-130 aircraft equipped with Modular Airborne FireFighting Systems which convert them to air tankers have been activated.
Can the fire be stopped?
If it has not happened already, by the end of the day on Sunday the fire will reach the 100,000-acre threshold to be called a “megafire”– a status that until a decade or two ago was rare.
Under these conditions with the predicted weather, the heavy fuel loads, and historically low fuel moistures, there is no possibility of stopping the forward spread of the fire. There is no number of 747 air tankers or firefighters on the ground that could be effective against the flaming front of this raging inferno. The best they can hope for is to find areas on the heel and flanks where the topography and vegetation are conducive to constructing indirect or direct fire lines, and firing out when appropriate, perhaps at night when weather conditions are more likely to lead to success.
Colorado DFPC SLV Engine 4321 on the Dixie Fire, California, 2021. DFPC photo.
A letter from the US Forest Service’s new Chief, Randy Moore, dated August 17, 2021 could lead a person to believe that Federal firefighters might be restricted from traveling to wildfire assignments. The initiative apparently stemmed from a July 29, 2021 White House statement:
Anyone who does not attest to being fully vaccinated will be required to wear a mask on the job no matter their geographic location, physically distance from all other employees and visitors, comply with a weekly or twice weekly screening testing requirement, and be subject to restrictions on official travel.
The Chief Moore document says all federal agencies are working to establish specific safety protocols for fully vaccinated individuals and those who are not fully vaccinated. These protocols will be consistent with the Centers for Disease Control and Prevention (CDC) July 27, 2021 guidance and align with the revised model safety principles from the Safer Federal Workforce Task Force.
The last link above is from, Safer Federal Workforce Task Force COVID-19 Workplace Safety: Agency Model Safety Principles, Issued July 29, 2021. Here is the section on travel:
Federal employees should adhere strictly to CDC guidelines before, during, and after travel.
For Federal employees who are fully vaccinated, there are no Government-wide restrictions on travel (although agency travel policies still apply).
For Federal employees who are not fully vaccinated or who decline to provide information about their vaccination status, official domestic travel should be limited to only necessary mission-critical trips. International travel should also be avoided, if at all possible, unless it is mission critical (e.g., military deployments, COVID-19 response deployments or activities, diplomats traveling, high-level international negotiations that cannot occur remotely). Heads of agencies should issue specific guidance to account for the particulars of their agency’s mission.
So after wading through all those documents, including a post from Chief Moore that triggered this journey of discovery, it at first appears that only “mission critical” travel will be allowed unless you are an international diplomat or a member of the military.
But all this is left up in the air, for now, since the letter says, instead of using clear text, the USFS is “moving forward … to establish specific safety protocols.”
Of course if the five federal agencies that fight wildland fire simply decree that firefighting is “mission critical”, end of discussion.
In an August 20 article, the Redding Record Searchlight, a Northern California newspaper, reported that CAL FIRE said there have been 14 positive cases at the Dixie Fire’s West Zone fire camp.
The positive cases include five from one crew, two from the same dozer, two from the same water tender and five “random cases,” the agency said. “These personnel were immediately released from the incident.”
Two of the cases led to hospitalizations, with one individual now in San Diego, who Cal Fire said is “doing well.” A second person, now in Redding, is “showing improvements,” the agency said.
In October of last year while working on the August Complex of fires, 9 of the 14 members of an Area Command Team that were working out of the Shasta-Trinity National Forest Supervisor’s Office in Redding tested positive. The first case was discovered after the team had been released and they were all in travel status followed by days off. That made it difficult to contact everyone. Some family members of individuals who tested positive also became infected. Given these unintended outcomes, a Facilitated Learning Analysis was initiated to develop lessons learned that could be shared with the wildland fire community.
The next four all occurred in California this year:
Four days after the crew began their season, one person tested positive. The crew Superintendent and Forest took immediate action to identify close contacts; 19 employees were identified. Of the 19, 7 were fully vaccinated (and returned to work immediately) and 12 were placed into quarantine (some at home and some in hotels).
On May 14th a fuels module member developed COVID-like symptoms; the person received a positive COVID test on May 16th. Contact tracing identified 10 close contacts (7 other fuels crew members and 3 additional employees who worked in the building). All of the close contacts were encouraged to get tested for COVID-19 and advised to quarantine (although 4 had been vaccinated, it was not used in the decision). One unvaccinated individual lived in barracks and moved to a hotel on the 16th. A second individual (the supervisor of the module) tested positive on May 17th.
Two additional cases were confirmed later that week (4 total in the cluster); none of the vaccinated employees tested positive or showed any symptoms. At the time of the review (June 2), one of the sick employees had returned to the office and others were teleworking. One of the four individuals was contacted by county public health, two were contacted by state public health, the fourth individual was never contacted by any public health department.
The four vaccinated employees did not get sick while four of the seven unvaccinated employees ultimately tested positive
An Interagency Hotshot Crew (IHC) finished a 14-day assignment with 18 crewmembers and arrived home June 22, 2021 (the IHC had 2 additional crewmembers who returned early and were not exposed); no employees were aware of exposure or had symptoms. The IHC was off duty on June 23-24, 2021 for mandatory rest.
On June 24th a crewmember developed a fever and took the initiative to get a COVID test immediately; the test returned a positive result the same day. Contact tracing found that the 17 other crewmembers were close contacts within 48-hours prior to the onset of symptoms. All of the close contacts were other IHC crewmembers (during travel home) and no other personnel were identified.
Of the 18 crewmembers who returned from assignment on June 22nd, 3 were fully vaccinated and returned to work on June 25th. The remaining employees (15) have not returned to work; the sick employee was put into isolation and the remaining close contacts on the crew were told to self-quarantine for 14-days by unit leaders. The 2 crewmembers who returned early (1 vaccinated) were not impacted.
None of the vaccinated employees got sick while 6 of the unvaccinated employees have tested positive.
On July 6, 2021, the local county public health contacted the Forest Service regarding an employee who had been exposed to a confirmed case of COVID-19. The employee had no symptoms and received negative test results (rapid test and PCR test). Public health advised the employee to quarantine for 10 days.
No other FS employees were involved in this exposure since they were considered a secondary contact because the employee was exposed outside of work.
The employee in quarantine impacted the availability of a fire engine during high fire danger, therefore an employee from a different station began working on the engine on July 6, 2021.
On July 7, 2021, the employee covering for the engine (from the other station) developed COVID-like symptoms and tested positive for COVID-19 on the same day.
This cluster involves 12 employees, with only 1 vaccinated and one who was in quarantine and not exposed. By July 12, 6 of the unvaccinated employees tested positive for COVID -19. All unvaccinated employees (10) were placed into quarantine. One employee chose to stay in a hotel and all others remained at their residences.
The vaccinated employee did not get sick while 6 of 11 unvaccinated employees have tested positive for COVID-19.
Lessons to be learned?
While the Delta variant, which began spreading widely in the United States in July, changed how easily it is to become infected even among those who are vaccinated, it is still true that a vaccination greatly reduces a person’s chance of severe infection, hospitalization, and death.
Here are the final paragraphs from an excellent, detailed article published August 18, 2021 at Healthline:
Vaccines are highly effective even if they’re not perfect
The COVID-19 vaccines were developed to stop developing severe forms of the disease that can lead to hospitalization and death. In that aspect, they have been extremely successful even if the vaccines are not 100 percent effective.
While it is true that some partially and fully vaccinated people have developed COVID-19, breakthrough infections should not be a concern for most of the population. Doctors, however, do still recommend people exercise caution in areas with low vaccination rates and high transmission.
Vaccines also greatly reduce the likelihood of mild and symptomatic infections as well as prevent death and hospitalization.
Kullar noted that the Delta variant is both more contagious and transmissible, and those who are harboring the Delta variant can carry as much as a 1,200 times higher viral load than the original strain.
“Given all of this information, it is important for everyone not only to get fully vaccinated but also follow infection prevention measures, such as wearing a face mask in the public, physically distancing from others, and avoiding large crowds until we round the turn of this surge.”
Fire officials have documented the destruction of 179 residences
8:28 a.m. PDT August 21, 2021
Caldor Fire map. The black line was the perimeter at 8:25 p.m. Aug. 20, 2021. The red dots represent heat detected by a satellite at 3:09 a.m. PDT Aug 21.
The 82,000-acre Caldor Fire southwest of Lake Tahoe is under a Red Flag Warning Saturday for conditions that could push the blaze northeast toward Highway 50.
The updated weather forecast for the fire area Saturday at 4,400 feet is for 14 mph southwest winds beginning at 11 a.m. gusting to 21 mph. The relative humidity will drop from the overnight high of 55 to 60 percent to the high 20s. There will be a 35 percent cloud cover with a high of 75 degrees.
To see all articles on Wildfire Today about the Caldor Fire, including the most recent, click HERE.
About two-thirds of the fire perimeter was active enough Friday night and early Saturday morning for satellites to detect intense heat.
Firefighters reported that winds decreased during the night and spot fires continued to become established in the dense timber stands and clear cuts due to the large amount of extremely dry dead and down material. The increase in relative humidity during the night allowed crews to conduct firing operations.
On the east side, satellites detected heat at 3:09 a.m. north of the Omo Ranch, and south, east, and northeast of Jenkinson Reservoir. The fire was also very active on the entire east side near Morrison, Iron Mountain, Iron Mountain Ridge, Voss, Meiss, and Caldor. At that time the fire was less than a mile south of Highway 50 at Riverton, and about two miles south of the highway near Kyburz. On the south side, satellite data overnight detected it was two miles north of Highway 88 at the closest point, Gold Note Ridge.
Crews have documented 179 residences that have been destroyed. Approximately 15,000 remain threatened.
Resources assigned to the fire Friday evening included 28 crews, 142 fire engines, and 20 helicopters for a total of 1,558 personnel.
8:27 p.m. PDT August 20, 2021
Caldor Fire map. The red dots represent heat detected by an aircraft at 2:48 p.m. PDT August 20, 2021. The fire perimeter was mapped earlier.
With strong winds in the forecast for Saturday officials have closed a portion of Highway 50 near the Caldor Fire which has burned over 75,000 acres 18 miles southwest of Lake Tahoe in California.
The closure began at 4:30 p.m. Friday. Highway 50 will be closed in both directions from the Sly Park Road exit to Twin Bridges. It will be open between Meyers and Twin Bridges for local residents only who reside between Meyers and Twin Bridges. These residents will be subject to providing identification and proof of residency. No traffic will be allowed west of Twin Bridges. (This information was acquired at 7 p.m. PDT Friday, Aug. 20, 2021, and could change.)
At 3 p.m. Friday the north edge of the Caldor Fire was about a half mile south of the highway. (See the map above.) A Red Flag Warning will be in effect Saturday from 11 a.m. through 8 p.m. The weather forecast for Saturday at 4,600 feet is for southwest and west-southwest winds beginning at 8 a.m. increasing in strength by 11 a.m. to 16 mph gusting to 25 mph, or 30 mph in some areas. The relative humidity will drop to 25 percent or lower. Skies will be clear with a high of 75 degrees.
Strong winds with no cloud cover and 25 percent humidity could push the fire to Highway 50 and possibly across the roadway. However a dense smoke layer could reduce solar preheating of the fuels and attenuate the spread somewhat. The Hot-Dry-Windy Index for Saturday predicts the area will be below the 50th percentile, which would not indicate extreme spread of a fire. This weather event will be a good test of the Index.
Many areas are under evacuation orders. InciWeb has the details.
On Friday the fire activity increased after noon when the wind began coming out of the south at 6 to 10 mph gusting to 23.
The fire spread is being driven by a heavy component of dead and down fuels and drought-stressed vegetation. Live fuels are cured to levels normally seen in late September, and the vegetation is extremely receptive to spotting. Fuel moistures are historically low.
Fire officials have documented the destruction of 118 residences.
Resources assigned to the fire include 18 crews, 109 fire engines, and 13 helicopters for a total of 1,118 personnel.
USFS engine crews on the initial attack of the Caldor Fire, August 14, 2021. USFS photo.
