This alert expired on 12 August 2026 at 20:15 UTC. It is kept here as a record.
No stronger detection stands among the 53 recorded within 20 km of this point since 8 March 2026 — 28 others scored the same. Another comparable one was recorded here earlier the same day. 9 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued August 12 at 3:09PM EDT until August 12 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 20, 2026 · score 52 · 3.9 km
- July 11, 2026 · score 52 · 4.2 km
- March 16, 2026 · score 52 · 8.5 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % 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 | 90% |
| Coordinates | 30.6312, -81.3512 |
| Nearest City | St. Marys (22 km) |
| Population Exposed | 1.1M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-12T19:09:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.f3e52308df99c343c70fb812c891014e |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM; Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM; Coastal waters from St. Augustine to Flagler Beach FL out 20 NM; Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM; Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM; Waters from St. Augustine to Flagler Beach FL from 20 to 60 NM; Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM; Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM; Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM; Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM; Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM; Waters from Fernandina Beach to St. Augustine FL from 20 to 60 NM |
| Headline | Special Marine Warning issued August 12 at 3:09PM EDT until August 12 at 4:15PM EDT by NWS Jacksonville FL |
| Expires | 2026-08-12T16:15:00-04:00 |
| SenderName | NWS Jacksonville FL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.f3e52308df99c343c70fb812c891014e862216d9.001.1","noaa_urn:oid:2.49.0.1.840.0.465c199dfcbfd7837bd4d3f991fe60e5bf464b6f.001.1","noaa_urn:oid:2.49.0.1.840.0.de6befb3c909b84726f21ae699008a086809d99b.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 47 |
| Iem Unit | MPH |
| Iem City | 2 NE Jacksonville Inter |
| Iem County | Duval |
| Iem State | FL |
| Iem Wfo | JAX |
| Iem Remark | ASOS station KJAX Jacksonville Intl Airport measured a peak wind gust of 47 mph. |
| MergedSources | [{"id":"iem_G_30.390_-81.480_1786556040000","source":"iem","severity":"low","severityValue":25,"timestamp":1786556040000,"latitude":30.39,"longitude":-81.48},{"id":"iem_G_30.390_-81.500_1786556400000","source":"iem","severity":"low","severityValue":25,"timestamp":1786556400000,"latitude":30.39,"longitude":-81.5},{"id":"iem_G_30.500_-81.680_1786559460000","source":"iem","severity":"low","severityValue":25,"timestamp":1786559460000,"latitude":30.5,"longitude":-81.68}] |
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 187 scientific monitoring sources.