Board examines risk-modeling request from Energy Safety and plans advice on extreme scenarios

Sean Richards and the board’s risk-modeling committee summarized a formal request from the Office of Energy Infrastructure Safety asking the Wildfire Safety Advisory Board to assess whether electric utilities’ risk models adequately consider realistic extreme scenarios—specifically extreme winds, very high vapor-pressure deficits and the exceptional vegetation growth that preceded the January 2025 fires.

Richards reviewed observed conditions: gauges recorded very low relative humidity (single digits to teens) and large temperature swings around the ignition dates; local stations observed wind speeds in the high percentiles (near the 98th percentile for some measurements). He noted Cal Fire and other analyses reported above-average herbaceous fuel loading across many grass‑dominated systems. Board staff explained that utilities use different operational thresholds (for instance wind-speed triggers used for PSPS), and planning models sometimes rely on annualized expected-value calculations rather than tail-risk metrics.

Committee staff briefed the board on work to compare utilities’ operational thresholds and planning-model practices. The committee intends to examine how extreme scenarios are represented in planning simulations, whether modelers capture combined drivers (wind + antecedent fuel dryness), and how extreme inputs affect decision priorities and grid-hardening cost-benefit outcomes. Staff noted that some utilities already incorporate extreme-scenario simulations in planning; others rely on thresholds used in operations and may not be modeling the same joint extremes.

The committee outlined an analytical plan: consult IOU and POU modelers and operations staff, gather technical documentation, run comparative model analyses, and publish a draft report for public comment (planned for October 2025) with a final report to the board in December 2025. The board and staff discussed the distinction between modeling for near-term operations (thresholds, PSPS) and long-term planning (cost‑benefit for grid hardening); Brian Landry (SCE) reminded the board utilities face regulatory constraints that can require expected‑value reporting and may limit the use of tail metrics for required filings.

Board members supported clarifying the operational vs planning use cases, urged the committee to preserve model transparency and to call out data gaps (for example localized wind networks, fuel characterization and structure‑level vulnerability), and requested that any recommendations describe which changes are actionable by utilities versus which require regulatory or legislative change.