Wisconsin outage planning is a cold-weather continuity problem first, with winter storms layered on top of repeated thunderstorm and flood exposure.
Wisconsin outage planning should start as a Great Lakes winter-support problem, not with flood recency alone.
Great Lakes Winter and Storm Continuity
Wisconsin's strongest planning signal is cold-weather continuity, not flood recency. FEMA's top modeled hazard is Cold Wave, and NOAA's outage-relevant record is led by thunderstorm wind, winter storm, heavy snow, and flood activity. That combination fits a Great Lakes state where winter support remains central even when the most recent federal anchor includes flooding.
The county-level overlap is also more urban-suburban than a simple rural storm narrative suggests. HHS emPOWER counts 44,777 electricity-dependent Medicare beneficiaries statewide, and the public BPI layer flags Dane, Waukesha, Rock, Milwaukee, and Walworth. That means the practical Wisconsin case is not only rural storm prep. It is keeping refrigeration, communications, and medical continuity running through recurring winter and severe-storm disruptions in major counties.
FEMA DR-4477 covers Wisconsin severe winter storm and flooding damage from January 2020.
Source: FEMA DR-4477Evidence trail
These notes trace the editorial claims above back to FEMA, DOE, utility, or other cited records.
FEMA declaration count (9) from OpenFEMA API, deduplicated by disaster number, DR/EM/FM types, 2014-2023.
NRI composite score (78.6) from FEMA NRI county layer, population-weighted to state level; top modeled hazards are Cold Wave, Hail, and Tornado.
NOAA outage-relevant event mix is led by Thunderstorm Wind (6,544), Winter Storm (2,802), Heavy Snow (1,174), and Flood (999), with Dane, Grant, and Waukesha leading county counts.
HHS emPOWER counts 44,777 electricity-dependent Medicare beneficiaries statewide; Dane, Waukesha, Rock, Milwaukee, and Walworth qualify in the public BPI layer.
Wisconsin Severe Winter Storm and Flooding DR-4477 from FEMA disaster declaration records.
Structured FEMA NRI, HHS emPOWER, NOAA Storm Events, and EIA methodology is documented separately on the methodology page.
NRI's top modeled hazard is Cold Wave, while NOAA's outage-relevant record is led by Thunderstorm Wind, Winter Storm, Heavy Snow, and Flood events; Dane, Waukesha, and Rock all qualify in the public BPI layer..
NOAA storm-event records filtered to outage-relevant event types for Wisconsin. Counts reflect historical storm-event assignments, not confirmed utility outages.
Analysis window
2005-01 to 2024-12
Included storm-event records
14,105
Source as of
2026-03
Included exact NOAA event types for Wisconsin: 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 Wisconsin, Jul has the highest monthly count (2,651 records) , and Thunderstorm Wind is the leading event type. This chart shows frequency in NOAA records, not how severe a specific outage may be.
77.3% of listed records were matched directly to this county.
83.2% of listed records were matched directly to this county.
71.4% of listed records were matched directly to this county.
73.1% of listed records were matched directly to this county.
81.3% of listed records were matched directly to this county.
80.6% of listed records were matched directly to this county.
With the current Wisconsin NWS county crosswalk, mapped forecast zones are effectively 1:1 with counties, and no unresolved forecast zones were present in this state contract.
Direct county match
63.0%
Mapped from forecast zone
37.0%
Not assigned to county ranking
0.0%
Unresolved forecast zones
0
County-level HHS emPOWER counts for electricity-dependent Medicare beneficiaries in Wisconsin.
44,777 Medicare beneficiaries in Wisconsin have claims associated with electricity-dependent medical equipment. (HHS emPOWER, 2026-03)
County-level HHS emPOWER records for this state. Medicare enrollment data only. 72 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.
The GeneratorChecker Backup Priority Index is a county shortlist for backup planning, combining historically frequent outage-relevant storm activity with larger county counts of electricity-dependent Medicare beneficiaries. It is planning context, not a forecast or an outage guarantee.
BPI version
v1.0
Analysis window
2005-01 to 2024-12
Matched counties
72
Counties qualify for the public BPI only when both signals land at or above the 80th percentile within the state. The shortlist excludes low-base medical counties and counties with less than 30% direct NOAA county matching.
Qualifying counties shown on the page: 5.
Percentiles are computed within Wisconsin only and are not comparable across states.
1. DANE
County FIPS 55025
At-risk Medicare count
2,643
Storm-event records
397
Direct NOAA county match
77.3%
2. WAUKESHA
County FIPS 55133
At-risk Medicare count
2,896
Storm-event records
339
Direct NOAA county match
71.4%
3. ROCK
County FIPS 55105
At-risk Medicare count
1,389
Storm-event records
331
Direct NOAA county match
73.1%
4. MILWAUKEE
County FIPS 55079
At-risk Medicare count
6,019
Storm-event records
262
Direct NOAA county match
58.0%
5. WALWORTH
County FIPS 55127
At-risk Medicare count
822
Storm-event records
273
Direct NOAA county match
65.6%
Treat winter support as the base case, then add enough runtime for food and medical continuity in a multi-day storm.
Keep heating-system support, communications, and medical essentials online during a winter outage.
Load
1189W
Target
24h
Minimum
46,900 Wh
This assumes your home uses a fuel-fired heating system that still depends on blower power. It does not imply a portable power station can replace electric space heating.
Size this scenario in calculatorAdd refrigeration for a longer cold-weather outage where snow, ice, or storm cleanup extends the disruption.
Load
1396W
Target
48h
Minimum
110,100 Wh
This is the more realistic Wisconsin case for maintaining food, communications, and medical continuity through a multi-day winter event.
Size this scenario in calculatorCritical Note: No single portable power station in our database covers the full 24-hour baseline at this load (46,900 Wh target vs. 6,144 Wh max in our current database). Use solar recharge, load rotation, or expandable systems for longer events.
Letting the most recent flood declaration define the whole page when Wisconsin's stronger practical signal is cold-weather continuity.
Ignoring winter-support loads because summer storms and floods also appear in the declaration record.
Sizing around phones and lights only when refrigeration and medical continuity matter in major counties.
A 1,500W space heater drains a power station in 1-2 hours. Here's the honest math on battery-powered heating, plus smarter alternatives that actually work.
For home backup, you need surge capacity for fridge compressors and enough Wh for multi-day outages. Here are the best options from our database of 33 stations.
From CPAP to oxygen concentrators, here is a practical checklist for keeping medical equipment running during power outages. Includes sizing math and emergency contacts.
Composite score: 78.6 / 100
Rating: Relatively Low
Top modeled hazards: Cold Wave, Hail, Tornado
Hurricane score: 13.4
Winter Weather score: 70.1
Wildfire score: 34.8
Total (2014-2023): 9
Most recent: 2020-04-04 Biological
| Type | Count |
|---|---|
| Flood | 5 |
| Biological | 2 |
| Severe Storm | 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
Wisconsin has an NRI composite risk score of 78.6 (Relatively Low), with 9 federal declarations from 2014 to 2023. NRI's top modeled hazard is Cold Wave, while NOAA's outage-relevant record is led by Thunderstorm Wind, Winter Storm, Heavy Snow, and Flood events; Dane, Waukesha, and Rock all qualify in the public BPI layer..
For the primary scenario on this page (24-hour heating-support essential), the estimated minimum is 46,900 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 a short convenience outage when the realistic Wisconsin case is a longer cold-weather interruption. See the common mistakes section above for more state-specific pitfalls.
