Atlas Methodology

The peril model, explained.

Atlas United is a purpose-built deterministic peril model. Eight independently calibrated layers, fifty-three perils, validated against two decades of observed severe events. No black-box blending, no proprietary aggregator math — every score traces to a documented model component with version, calibration vintage, reason code (patent claim 30), and confidence interval.

ATMOS
Atmospheric & tropical layer
Hurricane intensity, track climatology, wind-field reconstruction, and high-resolution forecast wind grids. Calibrated against the full Atlantic basin tropical-cyclone catalog from 1851 forward.
  • Tropical-cyclone catalog · 1851–today
  • Sub-hour forecast wind grid
  • Surge basin envelope
  • Extreme precipitation atlas
Hazards servedHurricane · Storm surge · Pluvial flood · Wind climatology · SLR
v2024.3Live
SURFACE
Riverine & coastal flood layer
Special Flood Hazard Areas, multi-hazard risk index, and surge inundation by basin. Cross-validated against post-event flood-extent observations and disaster-declaration history.
  • SFHA polygons · live
  • Multi-hazard risk index
  • Disaster-declaration history
  • Mitigation project pipeline
Hazards servedRiverine flood · Multi-hazard · Disaster history
v2024.2Live
SEISMIC
Earthquake, landslide & volcanic layer
National seismic hazard model with peak-ground-acceleration grids, plus landslide susceptibility and volcanic exposure. 50-state coverage for seismic, regional coverage where geology requires it.
  • 50-state seismic hazard · 2023
  • Landslide susceptibility
  • Volcanic exposure zones
  • 3D elevation model
Hazards servedEarthquake · Landslide · Volcanic · Tsunami
2023 catalogQuarterly
WILDFIRE
Burn perimeter & WUI exposure layer
Burn-probability raster, fuel-model classification, and Wildland-Urban Interface exposure scoring. Calibrated against the full national fire-occurrence record and post-fire perimeter data.
  • Burn-probability grid
  • Fuel-model classification
  • Fire-occurrence catalog
  • Ember-zone overlay
Hazards servedWildfire · Burn probability · WUI exposure · Ember
v2024.1Live
CONVECTIVE
Hail, tornado & severe-wind layer
Convective-event archive spanning seven decades of tornado tracks, severe-hail reports, and damaging-wind events. The calibration set behind every convective peril Atlas grades.
  • Severe-event database
  • Tornado-track archive
  • Severe-hail catalog
  • Day-1 convective outlook
Hazards servedTornado · Hail · Severe wind · Lightning
1955–todayDaily
CHRONIC
Chronic-climate & long-horizon layer
Climate normals, billion-dollar disaster trends, and forward projections at 2030 / 2050 / 2100 horizons. Powers chronic peril scores: heat stress, drought, sea-level rise.
  • 1991–2020 climate normals
  • Monthly climate grids
  • Billion-dollar disaster catalog
  • 2030 / 2050 / 2100 projections
Hazards servedHeat · Cold · Drought · Sea-level · Trend
1991–2020Annual
INFRA
Infrastructure & environmental layer
Levee and dam exposure, air-quality monitoring, water-system records, and grid-reliability indicators. Captures the man-made systems that modulate peril outcomes around a parcel.
  • Levee & dam inventory
  • Air-quality monitoring
  • Water-system records
  • Grid-reliability metrics
Hazards servedLevee failure · Air quality · Outage · Habitability
v2024Quarterly
FORECAST
Forward probability layer
Sixteen-day forward-looking peril probability with sub-hour refresh on the convective component. The only Atlas layer that updates intra-day, used for accumulation control and CAT pre-positioning.
  • 16-day forward grid
  • Sub-hour convective refresh
  • Tropical-track ensemble
  • Daily severe outlook
Hazards servedAll convective · Tropical · Forward windows
LiveSub-hour
Validation

Calibrated against two decades of observed events.

Every Atlas peril layer is independently calibrated against a documented event catalog spanning at least 22 years of validated observations — and continuously back-tested against new severe events as they occur. We publish hit-rate statistics. Most peril vendors don't.

Citable in filings
Every score response includes model version, calibration vintage, and confidence interval — language ready to paste into a rate-filing exhibit.
Versioned and replayable
Pin a score to a specific model version and replay it years later. Useful for litigation, audits, and back-testing.
Published hit rates
We publish address-level verification statistics for every peril layer against post-event observations. Transparency is a feature, not a marketing asterisk.