Calwood Fire erupts northwest of Boulder, Colorado

It was plume dominated within an hour

Updated October 18, 2020    |    9:33 p.m. MDT

The Boulder Office of Emergency Management has released a preliminary list of the structures that were destroyed or damaged in the Calwood Fire. The list includes 23 homes described as a total loss. The process is ongoing and more buildings may be added as the surveys continue.

The weather on Sunday stopped the spread of the Calwood Fire which has burned 8,788 acres seven miles north-northwest of Boulder. Weather stations in the area recorded one or two hundredths of an inch of precipitation during the day while the humidity ranged in the 80s or 90s.

To see all articles on Wildfire Today about the Calwood Fire including the most recent, click here.

Firefighting aircraft were hampered by the weather in the morning but were back in the air in the afternoon.

Rain tweet Boulder CO
The Highway 36 camera near Altona showed rain on the lens and wet pavement Sunday morning.

The weather forecast is similar to the one for the Lefthand Fire — strong winds out of the west Sunday night at 16 mph gusting at 25  to 30 mph with the humidity in the 50s. For Monday expect decreasing west winds of 10 mph gusting to 17 while the RH drops to the low 20s. Tuesday will be about the same with slightly stronger west winds.

Updated October 18, 2020   |   7:16 a.m. MDT

The perimeter of the Calwood Fire in the map above was collected by a U.S. Forest Service fixed wing aircraft at 10:58 p.m. MDT October 17.  The preliminary estimated size at that time was 8,788 acres. The red shaded areas represent intense heat.

Boulder County has published a map with evacuation information.

Updated October 17, 2020   |   6:04 p.m. MDT

Map of the Calwood Fire
Map of the Calwood Fire at 2:44 p.m. MDT Oct. 17, 2020.

A fixed wing aircraft determined at 4 p.m. Saturday that the Calwood Fire had burned 6,600 acres.

Updated October 17, 2020   |    5:41 p.m. MDT

Map of the Calwood Fire
Map of the Calwood Fire from Colorado’s Multi-Mission Aircraft, the afternoon of Oct. 17, 2020. Spot fires had reached Highway 36 to the east. Time uncertain.

Colorado’s Multi-Mission Aircraft collected the data in the map above. The time on Saturday afternoon is not certain. The crew estimates the Calwood Fire had at that time burned about 3,300 acres. Spot fires have reached Highway 36 to the east.

Boulder County has information about evacuations that have been ordered.

Calwood Fire at Hwy. 36
Calwood Fire at Hwy. 36 north of Nelson Rd at 4:05 pm Oct. 17, 2020. Colorado state highway camera.

The Calwood Fire northwest of Boulder, Colorado has spread to the east, reaching Highway 36 (N. Foothills Highway), or at least spot fires have.

Cameron Fire,
Cameron Fire, posted at 4:18 p.m. MDT Oct. 17, 2020.

October 17, 2020   |    3:33 p.m. MDT

Map of the Calwood Fire
Map of the Calwood Fire at 1:54 p.m. MDT Oct. 17, 2020. After this satellite overflight the fire spread to the east, reaching highway 36.

A new fire in Colorado that was reported at 12:17 p.m. MDT Saturday developed a large smoke plume within the first hour. The Calwood Fire is about 9 miles northwest of Boulder and is spreading quickly pushed by an 11 mph wind out of the north-northwest with gusts up to 30 mph. At 2:30 p.m. MDT it was estimated to be 1,000 acres.

The Boulder County Office of Emergency Management reported at 1:48 p.m. that the town of Jamestown was being evacuated.

Map of the Calwood Fire
Map of the Calwood Fire from Colorado’s Multi-Mission Aircraft at about 2 p.m. MDT Oct. 17, 2020. Jamestown is in the bottom-left corner of the map.

At 3:05 p.m. a weather station northwest of Boulder reported 46 degrees, 23 percent relative humidity, and wind out of the southwest or south-southwest at 5 to 8 mph gusting to 22 mph. The wind is expected to decrease Saturday night and the relative humidity will increase substantially, but breezy conditions with wind gusts in the 20s will exist off and on through Tuesday.

A Red Flag Warning is in effect until 6 p.m. local time.

Calwood Fire
Calwood Fire at about 2 p.m. MDT Oct. 17, 2020 by L. M. Galamore.
Colorado fires satellite photo
Satellite photo showing heat detected by a satellite on fires in Colorado at 2:21 MDT Oct. 17, 2020.

Thanks and a tip of the hat go out to LM.

Typos, let us know HERE, and specify which article. Please read the commenting rules before you post a comment.

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.

15 thoughts on “Calwood Fire erupts northwest of Boulder, Colorado”

  1. Some fires are misnamed. The 2017 Tubbs Fire actually started on Bennett Lane a few miles north of Tubbs Lane. Maybe the initial caller was mapatologically challenged . . .

  2. I do have to say I like being able to scroll in on the maps now. Having done that though I can now see all of the houses and properties that are is serious danger. Pray for some rain…or even better some snow…

  3. Sorry to be ‘that guy’ but where do the come up with these weirdo names for wildfires? “Cal-Wood Fire” the f**k? Hurricanes get the old Jane, Thom, Sally, etc. *yawn*
    Wildfires it’s like “Hydro Blankenship Fire”, “Poughkeepsie Springtime Fire”, and “Sprunkton Sunrise Canyon Fire”. Then you try to look up ‘Sprunkton Sunrise Canyon’ it DOESN’T EXIST was just made up…

    1. The method for naming a fire depends upon local jurisdiction, but the most commonly accepted protocol is to use the closest geographic feature or map location (usually using US Geologic Survey topographic maps, 7.5 minute series) as the name for the fire. In the case of the Cal Wood fire, the point of origin or reporting party’s location was the Cal-Wood Educational Center / Ranch in Boulder County. Use of person’s names, humorous phrases, etc are generally frowned upon. The biggest issue with naming fires is to make sure that the initial attack resources get the correct spelling/identification of the location to the dispatch center – once a fire is named it is difficult to change it. Hope this helps folks understand this fire and other fire names better.

    2. If you think names of a fire are an issue our justification just numbers them. Names give a fire character and are 100 % better IMHO

    3. Oo…I like you! You got a pretty mouth too. You’re right though…pondering the thought of these bozos behind a desk who come up with the names. Don’t feel left out ok…cause they do it to us here too in Californication. CampFire, ButteFire etc. Take care & keep raking Colorado

  4. I know that map legends may have been missing from your original sources, but not knowing what the various colors on the multi mission aircraft CalWood map represent is frustrating.
    Other than that, thank you very much for all of the information!


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