Wildfire Exposure Situation Report · Intermountain West (Utah, Colorado, Nevada)

Capybara Center for Risk Analysis · situation report · under JANUS

Wildfire Exposure Situation Report · Intermountain West

Posterior-weighted expected exposure for Utah, Colorado and Nevada, triangulated against the federal fire outlook

HazardWildfire, short-horizon exposure

AreaUtah, Colorado, Nevada (three runs)

Run windowEarly July 2026 (execution-time)

HorizonGFS short-term, ≤504 h (~21 days)

Provenance. Legacy Capybara Bayesian wildfire model (Google Earth Engine). Current fields key off execution time; the FIRMS active-fire overlay shows the last 7 days. Config: GFS ≤504h · fineScale=500 · exposureScale=1000 · profile=standard · ENSO: el_nino (2019, 2023, 2024). Code as FDO: the legacy script will be archived as a citable release; claims carry derivedFrom: capybara-legacy [PID pending].

Legend modeled exposure: low → high (grey, amber, orange, dark red) FIRMS active fire, last 7 days (observed, separate layer) white / pale = salt flats, water or no-fuel base, not risk

Across three runs, the model concentrates wildfire exposure in the wildland terrain of the Intermountain West: the central Utah highlands stand out as the densest high-intensity cluster, with additional flagged terrain across the Colorado mountains and the ranges of northern Nevada. Urban cores (Salt Lake City, Denver, Las Vegas, Reno) sit largely outside the flagged surface. The figures are scenario estimates of exposure, not predictions of ignition, and the federal outlook for the same window is consistent with the flagged geography, which is corroboration, not predictive skill.

§0Reading these maps

On the risk surface, dark red is the highest modeled-exposure class, then orange, then amber, over a grey base. The bright yellow patches are a separate FIRMS layer showing fire observed in the last 7 days, not the top risk class. White and pale speckled areas, such as the Great Salt Lake Desert, are salt flats, water or no-fuel base rather than risk. One important caveat applies to every table: the totals are the model's in-domain denominators for the analyzed terrain, which are smaller than full state populations, so the population figures are within-study-area, not statewide.

§ARun A · Utah–Colorado regional

A single regional run over the central Rockies and Colorado Plateau, shown here at two pans. The Utah view resolves a dense band of high-intensity cells across the central Utah highlands (Wasatch Plateau, Fishlake and Manti-La Sal country), with a FIRMS active-fire cluster in south-central Utah. The Colorado view shows more scattered flagged terrain across the western ranges (White River, Grand Mesa, Uncompahgre and the San Juans), with active-fire detections near the southwestern Colorado mountains. The Front Range urban corridor is largely outside the flagged surface.

Run A, Utah pan. Dense high-intensity cells across the central Utah highlands; yellow marks observed active fire (FIRMS, last 7 days).

Run A, Colorado pan. Same run, eastern view: scattered flagged terrain across the Colorado ranges; Front Range largely low.

Asset	Share	Expected (in-domain)	Total
Population	1.2%	~45,700 ppl	3,735,711
Cropland	4.6%	~67,900 ha	1,490,530
Protected areas	1.7%	~46,200 ha	2,694,146
Built-up footprint	2.4%	~646,500 ha	26,952,953
Electric grid	2.8%	~519 km	18,551 km
Roads	2.7%	~631 km	23,720 km
Urban area	0.7%	~1,960 ha	297,960 ha
Wind / solar farms	0% / 1.8%	0 / 1 sites	24 / 38

§BRun B · Utah (state-clipped)

A separate run clipped to the Utah state boundary. Flagged cells concentrate in central and southern Utah (Fishlake, Beaver and the Color Country / Dixie highlands), with a FIRMS active-fire cluster near Beaver. The white speckled zone in the northwest is the Great Salt Lake Desert and Bonneville salt flats, a no-fuel base rather than risk. The standout statistic is cropland: 13.0% of in-domain cropland falls in the flagged band, far above the population share, meaning the flagged terrain intersects irrigated and dry-farm land disproportionately.

Run B, Utah. Central and southern Utah flagged; white northwest is salt flats (no-fuel base); yellow is observed active fire.

Asset	Share	Expected (in-domain)	Total
Population	2.3%	~43,700 ppl	1,941,338
Cropland	13.0%	~33,830 ha	259,910 ha
Protected areas	1.7%	~46,300 ha	2,774,200 ha
Built-up footprint	2.4%	~520,800 ha	21,966,264 ha
Electric grid	4.1%	~368 km	9,013 km
Roads	3.5%	~560 km	16,127 km
Urban area	1.2%	~1,884 ha	155,673 ha

§CRun C · Nevada (state-clipped)

A run clipped to Nevada. Flagged cells are sparser and concentrate in the ranges of northern Nevada (Humboldt-Toiyabe country), with southern Nevada and the Las Vegas basin largely outside the surface. As in Utah, cropland is the most disproportionately exposed asset at 11.4%, against a population share near 1%.

Run C, Nevada. Sparse flagged terrain concentrated in northern Nevada ranges; southern Nevada largely outside the surface.

Asset	Share	Expected (in-domain)	Total
Population	1.0%	~17,300 ppl	1,715,014
Cropland	11.4%	~13,430 ha	117,928 ha
Protected areas	1.6%	~71,800 ha	4,392,866 ha
Built-up footprint	1.7%	~492,000 ha	28,634,224 ha
Electric grid	1.5%	~135 km	9,243 km
Roads	2.7%	~319 km	11,946 km
Urban area	0.7%	~1,207 ha	162,724 ha

§DWhat the three runs share

Three findings hold across the runs. First, population and urban exposure are low everywhere (roughly 1 to 2 percent), because the flagged surface sits in sparsely populated mountain and wildland terrain rather than the urban cores. Second, cropland is the most disproportionately exposed asset in the state-clipped runs, 13.0% in Utah and 11.4% in Nevada, pointing to a wildland-agriculture interface risk that a population-only reading would miss. Third, the central Utah highlands are the single most intense and contiguous cluster across every view, making them the clearest candidate for a structural, prior-dominant follow-up run.

§ETriangulation against the federal outlook

Corroboration · NIFC, issued 1 July 2026

The National Interagency Fire Center's Significant Wildland Fire Potential Outlook for July, issued 1 July 2026, forecasts above-normal significant fire potential across much of the Great Basin and the Greater Four Corners, the region these runs cover. It reports live fuel moisture at record-dry levels across the southern Great Basin in June and dead fuel moisture below the 10th percentile, with temperatures several degrees above normal and precipitation well below normal. Notably, the outlook excludes portions of southern Nevada from the July above-normal area, which matches this model concentrating Nevada exposure in the north rather than the south. The agreement establishes that the flagged geography is plausible and shared with the federal assessment; it does not establish model skill, which only outcome tracking can show.

{ "@id": "nanopub:tri_IMW_NIFC_2026-07",
  "assertion": { "subject": "model exposure surface, Great Basin + Four Corners (UT/CO/NV)",
    "predicate": "corroboratedBy",
    "object": "NIFC July 2026 outlook: above-normal significant fire potential" },
  "provenance": { framing: "consistency, not predictive skill",
    source: "nifc.gov, issued 2026-07-01", detail: "southern Nevada excluded, matches model",
    derivedFrom: "capybara-legacy [PID pending]" },
  "pubInfo": { "identifier": PID pending, "license": "CC-BY-4.0" } }

§FRecommended use

1. Treat these surfaces as operational readiness guidance for the coming weeks, not as a map of where fire will occur.
2. Commission a prior-dominant structural run over the central Utah highlands, the standout cluster, before siting durable fuel treatment.
3. Read the cropland exposure to agricultural and rangeland stakeholders, since it is far higher than the population share and is easy to miss.
4. Cross the flagged terrain with the FIRMS active-fire layer to separate observed events from modeled risk when briefing responders.
5. Freeze and date this report at issuance so its scenarios can be evaluated against the season that follows.

§GAssumptions & how to read the figures

The model returns a probability-weighted exposure field, not a point prediction. Percentages are the expected share of each in-domain asset within the flagged surface under the stated configuration. They are estimates for planning, not counts of confirmed or expected events, and have not been validated against realized outcomes. Standing assumptions: the El Niño analog baseline as the reference for the period, the skill of the GFS forecast near 504 hours, and dependence on recent fire history.

§HSources

• National Interagency Fire Center. National Significant Wildland Fire Potential Outlook, issued 1 July 2026. nifc.gov
• National Interagency Coordination Center. Outlooks (product description and archive). nifc.gov
• Drought.gov. National Significant Wildland Fire Potential Outlook. drought.gov

Capybara Center for Risk Analysis · Tecnológico de Monterrey · under the JANUS framework (Feged-Rivadeneira, 2025; archived release doi.org/10.5281/zenodo.21170613).
Legacy model run. Probabilistic exposure estimates, not deterministic forecasts of ignition or damage. Triangulation establishes consistency, not predictive skill.