This alert expired on 2 September 2026 at 01:00 UTC. It is kept here as a record.
No stronger detection stands among the 44 recorded within 20 km of this point since 29 June 2026 — 33 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 1 at 7:33PM CDT until September 1 at 8:00PM CDT by NWS Sioux Falls SD
Nearby, since 29 June 2026
- June 29, 2026 · score 16 · 20.4 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 65 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | high |
| Calamity Score (ours) | 28 / 100 |
| Our confidence | 65% |
| Coordinates | 42.6448, -98.2616 |
| Nearest City | Norfolk (97 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-02T00:33:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.deaf0d5e1df726d194c1595e5e5caf682773c858.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Bon Homme, SD; Charles Mix, SD; Holt, NE; Boyd, NE; Holt, NE and 1 more areas |
| Headline | Severe Thunderstorm Warning issued September 1 at 7:33PM CDT until September 1 at 8:00PM CDT by NWS Sioux Falls SD |
| Expires | 2026-09-01T20:00:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.deaf0d5e1df726d194c1595e5e5caf682773c858.001.1","noaa_urn:oid:2.49.0.1.840.0.b0a7009363c54481ad230b36ddb2d37b4184ae13.001.1","noaa_urn:oid:2.49.0.1.840.0.31ccbfa14d2f3d2494f820a28c1d59e791540416.001.1","noaa_urn:oid:2.49.0.1.840.0.b4a93174b864b0b57d4f3fdc7ff300206adf2188.001.1"] |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 6 NNW Chambers |
| Spc County | Holt |
| Spc State | NE |
| Spc Comments | Social media report via storm chaser stream. (LBF) |
| MergedSources | [{"id":"spc_wind_43.09_-98.32_29","source":"spc","severity":"medium","severityValue":45,"timestamp":1788309329578,"latitude":43.09,"longitude":-98.32},{"id":"spc_wind_43.09_-98.32_31","source":"spc","severity":"medium","severityValue":45,"timestamp":1788309329578,"latitude":43.09,"longitude":-98.32},{"id":"spc_wind_43.07_-98.33_36","source":"spc","severity":"medium","severityValue":45,"timestamp":1788309329578,"latitude":43.07,"longitude":-98.33},{"id":"spc_hail_42.95_-99.04_45","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.95,"longitude":-99.04},{"id":"spc_hail_43.02_-98.89_46","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.02,"longitude":-98.89},{"id":"spc_hail_43.02_-98.68_48","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.02,"longitude":-98.68},{"id":"spc_hail_43.07_-98.53_49","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.07,"longitude":-98.53},{"id":"spc_hail_43.06_-98.53_50","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.06,"longitude":-98.53},{"id":"spc_hail_42.98_-98.82_51","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.98,"longitude":-98.82},{"id":"spc_hail_43.13_-98.35_52","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.13,"longitude":-98.35},{"id":"spc_hail_42.70_-99.14_55","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.7,"longitude":-99.14},{"id":"spc_hail_42.84_-98.87_56","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.84,"longitude":-98.87},{"id":"spc_hail_42.99_-98.44_57","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.99,"longitude":-98.44},{"id":"spc_hail_43.03_-98.41_58","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":43.03,"longitude":-98.41},{"id":"spc_hail_42.26_-99.00_59","source":"spc","severity":"high","severityValue":65,"timestamp":1788309329579,"latitude":42.26,"longitude":-99},{"id":"spc_hail_42.28_-98.81_60","source":"spc","severity":"high","severityValue":65,"timestamp":1788308820000,"latitude":42.28,"longitude":-98.81}] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 10 February 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 28/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.