Forecast for strong winds closes Highway 50 near Caldor Fire

Fire officials have documented the destruction of 179 residences

8:28 a.m. PDT August 21, 2021

Caldor Fire map
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
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
USFS engine crews on the initial attack of the Caldor Fire, August 14, 2021. USFS photo.

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Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

3 thoughts on “Forecast for strong winds closes Highway 50 near Caldor Fire”

  1. I’m curious who gave the order to stand down and not fight the fire in grizzly flats. I was there moments before the fire. Did not see 1 crewmember attempting to save my families land or doing anything for that matter. Seems would be better to “fight fires” if they actually got out of their trucks…thanks for nothing our famies ranch is gone…the “firefighter” we talked to on our way out that was doing nothing said he was just their to observe…pathetic

    1. Absolutely agree!!! News Coverage????
      Where is the National Guard helping firefighters? Who are so “exhausted?” The East Coast gets a storm and news covers it all an emergency act and national guard all within one day.
      What about people losing their homes in this Caldor Fire? Why is any foreman OBSERVING?
      Many firemen staying at Harrah’s in South Lake Tahoe. See them coming in. Some going out to gamble and drink. Seriously??? Who pays for this? Let’s actually drop some water!!! If planes can see these hot spots where firemen cannot reach. Drop water!!!!! People would prefer to see water dropped than every day of we cannot use air resources due to smoke. Hello. That’s what fires produce. I am so sorry for your loss Rod.

  2. Thank you Bill for your tireless research that you have been bringing to us here in Reno, Nevada.

    It helps us to understand remotely in our homes the serious nature of this fire beast we are dealing with.

    Austin Air Putifiers, EbviroKlenz Air Ourifier and Aireox Air Purifuers are good for Severe Respirartory issues for people such as myself who are disabled in breathing

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    This is your choice who you secude but even one can make you safer

    Thanks again Bill, you are awesome keeping us ubformed.

    Lassen College back in the day had a fire crew and J qas their Secretary. I got up at all hours when I was called yo Fure dispatch.



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