Washington's outage planning splits between dense-corridor continuity around Puget Sound and very different inland wind, snow, and wildfire exposures east of the Cascades.
Washington's county signals point in two directions at once: King, Pierce, and Snohomish lead the medical-load totals around Puget Sound, while Spokane, Stevens, Pend Oreille, Okanogan, and Douglas lead the NOAA event record east of the Cascades.
Mixed Puget Sound, Inland-Wind, and Winter Risk
Washington's practical outage risk is split between dense Puget Sound continuity and eastern inland weather exposure. Heavy snow leads the NOAA event record, high wind sits second, and flood remains meaningful, which makes the state's statewide outage mix broader than a fire-led or winter-only description.
There is also no public top-priority BPI county layer in Washington. The strongest county signal comes from HHS emPOWER, with King, Pierce, Spokane, Snohomish, and Clark carrying the largest medical-device totals. That supports a dense-corridor baseline even while the NOAA event leaders sit farther inland.
The recent fire declaration is too narrow for Washington's statewide outage mix. DR-4682 covers severe winter storm, straight-line wind, flooding, landslides, and mudslides from the November 2022 event, which matches Washington's split continuity problem much more closely than another fire declaration would.
FEMA DR-4682 covers Washington's November 2022 severe winter storm, straight-line winds, flooding, landslides, and mudslides, declared in January 2023; a stronger statewide fit than the more recent fire declaration for the state's actual split between dense-corridor continuity and inland weather exposure.
Source: FEMA DR-4682Evidence trail
These notes trace the editorial claims above back to FEMA, DOE, utility, or other cited records.
FEMA declaration count (86) from OpenFEMA API, deduplicated by disaster number, DR/EM/FM types, 2014-2023; Washington's mix in this window includes Fire (70), Flood (6), Severe Storm (5), Biological (3), and Mud/Landslide (2).
NRI composite score (92.8) from FEMA NRI county layer, population-weighted to state level; top modeled hazards are Earthquake, Landslide, and Riverine Flooding.
NOAA outage-relevant event mix is led by Heavy Snow (2,632), High Wind (1,232), Thunderstorm Wind (444), Flood (395), and Strong Wind (287), with Spokane, Stevens, Pend Oreille, Okanogan, and Douglas leading county counts.
Washington has no public top-priority BPI counties in the GeneratorChecker cross-signal layer. HHS emPOWER counts 51,731 electricity-dependent Medicare beneficiaries statewide, with King (8,547), Pierce (5,866), Spokane (5,460), Snohomish (4,226), and Clark (3,530) as the largest county totals.
Washington's most recent fire declaration is FM-5481, while DR-4682 covers the broader winter, wind, flood, landslide, and mudslide mix from the November 2022 event. DR-4635 remains a secondary non-fire fallback from the same 2014-2023 window.
Structured FEMA NRI, HHS emPOWER, NOAA Storm Events, and EIA methodology is documented separately on the methodology page.
NRI's top modeled hazards are Earthquake, Landslide, and Riverine Flooding, while NOAA's outage-relevant record is led by Heavy Snow, High Wind, Thunderstorm Wind, Flood, and Strong Wind events..
NOAA storm-event records filtered to outage-relevant event types for Washington. Counts reflect historical storm-event assignments, not confirmed utility outages.
Analysis window
2005-01 to 2024-12
Included storm-event records
5,556
Source as of
2026-03
Included exact NOAA event types for Washington: Thunderstorm Wind, Tornado, High Wind, Strong Wind, Flash Flood, Flood, Winter Storm, Ice Storm, Freezing Rain, Heavy Snow, Blizzard.
In this filtered NOAA record set for Washington, Jan has the highest monthly count (1,231 records) , and Heavy Snow is the leading event type. This chart shows frequency in NOAA records, not how severe a specific outage may be.
1,124 events were not mapped to a county ranking.
846 events were not mapped to a county ranking.
12 events were not mapped to a county ranking.
184 events were not mapped to a county ranking.
159 events were not mapped to a county ranking.
12.3% of listed records were matched directly to this county.
9.8% of listed records were matched directly to this county.
7.9% of listed records were matched directly to this county.
22.7% of listed records were matched directly to this county.
4.4% of listed records were matched directly to this county.
8.5% of listed records were matched directly to this county.
Forecast-zone events in Washington are assigned to counties using the current NWS county crosswalk. Some forecast zones expand to multiple counties; unresolved legacy, coastal, and sub-county forecast zones fall into the excluded bucket.
Direct county match
18.7%
Mapped from forecast zone
38.1%
Not assigned to county ranking
43.2%
Unresolved forecast zones
54
County-level HHS emPOWER counts for electricity-dependent Medicare beneficiaries in Washington.
51,731 Medicare beneficiaries in Washington have claims associated with electricity-dependent medical equipment. (HHS emPOWER, 2026-03)
County-level HHS emPOWER records for this state. Medicare enrollment data only. 39 counties are included in this state snapshot.
Counties with higher concentrations may face elevated community-level demand for backup power during outages. This does not indicate individual medical necessity.
Limitations: Reflects Medicare beneficiaries with claims associated with electricity-dependent medical equipment. Does not capture non-Medicare or uninsured populations. HHS masks cells from 1 to 10 as 11.
Use a 24-hour Puget Sound continuity bundle as the baseline, then extend to 48 hours with heating-system support for inland wind and winter outages.
Primary Washington metro scenario: storm or local outage interrupts refrigeration, communications, medical support, and basic work continuity across the dense Puget Sound corridor.
Load
698W
Target
24h
Minimum
27,600 Wh
This is the dense-corridor baseline for Puget Sound and other major population centers.
Size this scenario in calculatorExtended Washington scenario: inland wind, snow, or storm outage where food preservation, communications, medical support, and a gas-heating blower all need to stay online.
Load
1396W
Target
48h
Minimum
110,100 Wh
This scenario adds heating-system support and does not model electric resistance heating.
Size this scenario in calculatorCritical Note: No single portable power station in our database covers the full 24-hour baseline at this load (27,600 Wh target vs. 6,144 Wh max in our current database). Use solar recharge, load rotation, or expandable systems for longer events.
Treating Washington as a fire-only state when the NOAA record is led by heavy snow and high wind.
Treating Washington as a Puget Sound-only state when the highest NOAA event counts sit east of the Cascades.
Inventing a public BPI county cluster where none exists.
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Composite score: 92.8 / 100
Rating: Relatively Moderate
Top modeled hazards: Earthquake, Landslide, Riverine Flooding
Hurricane score: 0.0
Winter Weather score: 81.1
Wildfire score: 74.2
Total (2014-2023): 86
Most recent: 2023-08-19 Fire
| Type | Count |
|---|---|
| Fire | 70 |
| Flood | 6 |
| Severe Storm | 5 |
| Biological | 3 |
| Mud/Landslide | 2 |
Required Wh = (Total Load W × Target Hours / Inverter Derate) × Safety Factor
Inverter derate: 0.70 (30% real-world loss)
Safety factor: 1.15
Rounding: Up to nearest 100 Wh
Washington has an NRI composite risk score of 92.8 (Relatively Moderate), with 86 federal declarations from 2014 to 2023. NRI's top modeled hazards are Earthquake, Landslide, and Riverine Flooding, while NOAA's outage-relevant record is led by Heavy Snow, High Wind, Thunderstorm Wind, Flood, and Strong Wind events..
For the primary scenario on this page (24-hour Puget Sound continuity), the estimated minimum is 27,600 Wh for a 24-hour target. Refine this in the calculator with your actual devices.
NRI is a modeled risk index based on hazard exposure, vulnerability, and expected loss. FEMA declarations reflect federally declared incidents. They answer different questions — use both signals together for planning.
Buying for one side of the state only and missing that Washington has both a dense-corridor continuity case and an inland duration case. See the common mistakes section above for more state-specific pitfalls.
