Firefighters slow the spread of Lefthand Fire west of Boulder, Colorado

One mile west of Ward, CO

October 20, 2020   |   8:40 a.m. MDT

Lefthand Fire
Lefthand Fire. Photo by @SteveStaeger October 18, 2020.

Firefighters have been successful in slowing the spread of the Lefthand Fire which has burned 470 acres 11 miles west of Boulder, Colorado. After it was reported at 12:41 p.m. October 18 it was attacked aggressively with what was described by the Operations Section Chief as “a million dollars worth of retardant”. In spite of the brisk winds, strong work by the aircraft and personnel on the ground kept it from becoming a second major fire in the Boulder area, along with the Calwood Fire northwest of the city.

On Monday the fire was largely above the inversion layer, so aircraft were used extensively to assist ground crews. Firefighters are constructing containment lines with the assistance of aircraft when possible.

Lefthand Fire breaks out 11 miles from Boulder, Colorado

Another fire near the front range of Colorado

Updated October 18, 2020   |    7:30 p.m. MDT

If you zoom in on the map above you will see the perimeters of both the Lefthand and the Calwood Fires. To make it easier to read you can remove the clutter by clicking on the box with three lines at top-right, then, Layers List. If you only want to see the fires themselves, un-click every layer except Incident Areas.

The Lefthand Fire has been mapped at 303 acres.

The fire was reported at about noon on Sunday. The DW5338 Nederland weather station south of the fire recorded 0.04″ of precipitation early Sunday morning, then the relative humidity remained above 80 percent until 1 p.m. These are not conditions that usually lead to the rapid spread of a vegetation fire. However, the area is in extreme drought, which has left the live and dead vegetation, the fuels, very dry. VERY DRY. So in spite of the small amount of rain, the desiccated fuels could still produce a fire that burned more than 300 acres. A few hundredths of an inch of rain may not have penetrated the tree canopies, leaving the ground fuels still very dry.

Those weather conditions help to explain the photo in the tweet below. If that really is ground fog in the drainage at lower-right, it’s very interesting. It is not common to see fog and a column of smoke from a 300-acre fire near each other at approximately the same elevation. Extreme drought helps to explain this.

If the weather Sunday had been hot, dry, and windy, the Lefthand Fire would still be hauling ass tonight.

Lefthand Fire tweet
Note what appears to be ground fog in the valley at lower-right.

But the weather is changing. At 7:13 p.m. Sunday the Nederland weather station recorded 53 degrees, 41 percent RH, and 5 mph winds out of the west-southwest gusting to 23.

The forecast for Ward just northwest of the fire, calls for westerly 30 mph winds Sunday night gusting to 48, with the relative humidity hovering around 50 percent. The winds will decrease somewhat on Monday to 16 mph with 27 mph gusts, still out of the west, with 22 percent RH. The conditions will be similar on Tuesday.

The short story is, unless firefighters were able to do some extraordinary work to contain the fire Sunday, we might be hearing much more about the Lefthand Fire.

Updated October 18, 2020   |   6 p.m. MDT

Calwood and Lefthand Fire
Map showing the proximity of the Calwood and the new Lefthand Fire.

Another fire has broken out near the front range of Colorado. The Lefthand Fire is east of Highway 72, 11 miles west-northwest of Boulder, and about a mile southeast of Ward.

The fire is in the 14,000 block of Lefthand Canyon Drive.

An evacuation has been ordered for the town of Ward and the areas north of Ward, Gold hill and the 10,000 block of Lefthand Canyon Drive. Included in the evacuation order are residents of Spring Gulch Road and Gold Lake Road.

The evacuation point is the Nederland Community Center, 750 CO-72, Nederland, CO 80466. Livestock should go to the Gilpin County Fairground 230 Norton Dr., Black Hawk CO 80422.

In addition to ground resources, a large air tanker was dispatched, followed later by the dispatch of three additional large air tankers and two very large air tankers (VLATs). Several single engine air tankers (SEATs) are also working the fire. It is not confirmed that the VLATs were actually available.

You can zoom in or out on the map below, which shows the reported location of the fire.

The fire is apparently named after the nearby Lefthand Canyon Drive and Lefthand Canyon.

We will post more information about the Lefthand Fire as it becomes available.

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