Right now
The most recent data we hold from NOAA arrived 4 hours ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 30 June 2026 at 07:00 UTC. It is kept here as a record.
No stronger detection stands among the 31 recorded within 20 km of this point since 16 March 2026 — 5 others scored the same. The last comparable one was on 1 June 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 30 at 1:25AM CDT until June 30 at 2:00AM CDT by NWS Sioux Falls SD
Urban PEI: 82,821 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- May 17, 2026 · score 39 · 6.3 km
- June 30, 2026 · score 45 · 24.1 km
How we know
10 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 45 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | High |
| Calamity Score (ours) | 45 / 100 |
| Legacy data-support index | 0.91/1 |
| Coordinates | 42.6562, -96.6131 |
| Nearest City | Sioux City (25 km) |
| Urban exposure index (PEI) | 82.8K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-30T06:25:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.23289aaeb848f25439632a444b71526f74f40abe.002.1 |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-06-30T06:25:00.000Z.
First archived: 2026-06-30T06:32:01.359Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Plymouth, IA; Sioux, IA; Woodbury, IA; Dakota, NE; Clay, SD; Union, SD |
| Headline | Severe Thunderstorm Warning issued June 30 at 1:25AM CDT until June 30 at 2:00AM CDT by NWS Sioux Falls SD |
| Expires | 2026-06-30T02:00:00-05:00 |
| SenderName | NWS Sioux Falls SD |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 5 WSW Wynot |
| Spc County | Cedar |
| Spc State | NE |
| Spc Comments | (OAX) |
| Iem TypeSummary | D |
| Iem City | Sioux Center |
| Iem County | Sioux |
| Iem State | IA |
| Iem Wfo | FSD |
| Iem Remark | Several large tree branches down across town ranging from 5 inches in diameter to as large as 13 inches in diameter. |
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.
Review the area, threshold and delivery channel in your account.
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