This alert expired on 10 August 2026 at 20:17 UTC. It is kept here as a record.
No stronger detection stands among the 48 recorded within 20 km of this point since 8 March 2026 — 29 others scored the same. Another comparable one was recorded here earlier the same day. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 10 at 4:09PM EDT until August 10 at 4:15PM EDT by NWS Jacksonville FL
An estimated 1,102,752 people live within 50 km of this point.
Nearby, since 8 March 2026
- June 27, 2026 · score 52 · 7.3 km
- July 11, 2026 · score 52 · 7.7 km
- August 8, 2026 · score 52 · 7.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 79 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 79% |
| Coordinates | 30.6531, -81.4600 |
| Nearest City | St. Marys (12 km) |
| Population Exposed | 1.1M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T20:09:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.773a9463b0deb978246c2dec17a8386dc8e62036.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Duval, FL; Nassau, FL |
| Headline | Severe Thunderstorm Warning issued August 10 at 4:09PM EDT until August 10 at 4:15PM EDT by NWS Jacksonville FL |
| Expires | 2026-08-10T16:17:00-04:00 |
| SenderName | NWS Jacksonville FL |
| 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 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 near St. Marys?
Calamity.live data shows a weather event with CalamityScore 52/100, near St. Marys (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.