Right now
The most recent data we hold from NOAA arrived 4 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
4 other detections within 20 km in the last 24 hours, the nearest 19 km from here.
This alert expired on 9 September 2026 at 00:00 UTC. It is kept here as a record.
No stronger detection stands among the 65 recorded within 20 km of this point since 16 March 2026 — 20 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 8 at 6:21PM CDT until September 8 at 7:00PM CDT by NWS Des Moines IA
An estimated 547,016 people live within 50 km of this point.
Nearby, since 16 March 2026
- May 19, 2026 · score 48 · 9.9 km
- July 21, 2026 · score 48 · 15.9 km
- July 21, 2026 · score 48 · 16.0 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 48 out of 100, at 87 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | High |
| Calamity Score (ours) | 48 / 100 |
| Our confidence | 87% |
| Coordinates | 41.6260, -93.3570 |
| Nearest City | Altoona (9 km) |
| Population Exposed | 547.0K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-09-08T23:21:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.d9d32a66a228cf70ce317710ebac6753853d5cea.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Jasper, IA; Mahaska, IA; Marion, IA; Polk, IA; Poweshiek, IA; Warren, IA; Boone, IA; Jasper, IA; Marshall, IA; Polk, IA; Story, IA |
| Headline | Severe Thunderstorm Warning issued September 8 at 6:21PM CDT until September 8 at 7:00PM CDT by NWS Des Moines IA |
| Expires | 2026-09-08T19:00:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.d9d32a66a228cf70ce317710ebac6753853d5cea.001.1","noaa_urn:oid:2.49.0.1.840.0.e64f0438f5e4c3c2584d0ac1ef7cd8aafaba52b4.001.1"] |
| Spc ReportType | wind |
| Spc Speed | 75 |
| Spc Location | 2 NW Ankeny |
| Spc County | Polk |
| Spc State | IA |
| Spc Comments | Measured gust from a Personal Weather Station. (DMX) |
| MergedSources | [{"id":"spc_wind_41.83_-93.80_0","source":"spc","severity":"medium","severityValue":45,"timestamp":1788907140000,"latitude":41.83,"longitude":-93.8},{"id":"spc_wind_41.76_-93.62_1","source":"spc","severity":"high","severityValue":70,"timestamp":1788908400000,"latitude":41.76,"longitude":-93.62}] |
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 8 March 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.
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