Right now
The most recent data we hold from NOAA arrived 14 minutes 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 31 July 2026 at 02:00 UTC. It is kept here as a record.
It is the 30th strongest of the 186 detections recorded within 20 km of this point since 15 March 2026. Another comparable one was recorded here earlier the same day. 8 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Watch issued July 30 at 3:29PM MDT until July 30 at 8:00PM MDT by NWS Rapid City SD
Nearby, since 15 March 2026
- August 31, 2026 · score 22 · 0.0 km
- August 27, 2026 · score 22 · 0.0 km
- August 12, 2026 · score 22 · 0.0 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 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 | Medium |
| Calamity Score (ours) | 22 / 100 |
| Legacy data-support index | 0.61/1 |
| Coordinates | 43.9000, -99.4000 |
| Nearest City | Mitchell (112 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-07-30T21:29:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Watch_noaa_urn:oid:2.49.0.1.840.0.27a5efb791ccfba9bb6eb0a8e1d3a761 |
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: 2026-07-30T21:29:00.000Z.
First archived: 2026-07-31T00:11:49.892Z. 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 Watch |
| Urgency | Future |
| Certainty | Possible |
| AreaDesc | Bennett, SD; Custer, SD; Fall River, SD; Jackson, SD; Mellette, SD; Oglala Lakota, SD; Todd, SD; Tripp, SD; Butte, SD; Haakon, SD; Harding, SD; Meade, SD; Pennington, SD; Perkins, SD; Ziebach, SD; Jones, SD; Lyman, SD and 2 more areas |
| Headline | Severe Thunderstorm Watch issued July 30 at 3:29PM MDT until July 30 at 8:00PM MDT by NWS Rapid City SD |
| Expires | 2026-07-30T20:00:00-06:00 |
| SenderName | NWS Rapid City SD |
| HasExactCoords | false |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.27a5efb791ccfba9bb6eb0a8e1d3a7610e7b1242.002.1","noaa_urn:oid:2.49.0.1.840.0.27a5efb791ccfba9bb6eb0a8e1d3a7610e7b1242.001.1","noaa_urn:oid:2.49.0.1.840.0.9b594b97f1653c76d69e287bd19696b25148ab6c.002.1","noaa_urn:oid:2.49.0.1.840.0.9b594b97f1653c76d69e287bd19696b25148ab6c.001.1","noaa_urn:oid:2.49.0.1.840.0.6b838714e123ddd8f25d9773f7acac36f93e3297.001.1"] |
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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