Right now
The most recent data we hold from NOAA arrived 4 hours ago, and this point is in it.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 28 September 2026 at 04:00 UTC. It is kept here as a record.
No stronger detection stands among the 18 recorded within 20 km of this point since 15 April 2026 — 13 others scored the same. The last comparable one was on 21 September 2026. 17 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 27 at 10:18PM CDT until September 27 at 11:00PM CDT by NWS Fort Worth TX
Urban PEI: 81,103 within a heuristic 50 km radius; not unique people.
Nearby, since 15 April 2026
- August 8, 2026 · 0.3 km
- September 21, 2026 · score 32 · 6.0 km
- September 20, 2026 · score 32 · 13.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 32 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 v5. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 32 / 100 |
| Legacy data-support index | 0.80/1 |
| Coordinates | 33.7638, -96.5000 |
| Nearest City | Denison (4 km) |
| Urban exposure index (PEI) | 81.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-28T03:18:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.d81385073d360890e9d2d99d68c36debb1c3ae7d.001.1 |
Physical priority index · v5. 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: 2026-09-28T03:18:00.000Z.
First archived: 2026-09-28T03:01:30.667Z. Material modification: 2026-09-28T03:22:41.095Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
1 retained revision changed source fields this page does not show; the index, severity and version stayed the same.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| MessageId | urn:oid:2.49.0.1.840.0.d81385073d360890e9d2d99d68c36debb1c3ae7d.001.1 |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Grayson, TX |
| Headline | Severe Thunderstorm Warning issued September 27 at 10:18PM CDT until September 27 at 11:00PM CDT by NWS Fort Worth TX |
| Expires | 2026-09-27T23:00:00-05:00 |
| SenderName | NWS Fort Worth TX |
| HasExactCoords | true |
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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