This alert expired on 16 March 2026 at 02:30 UTC. It is kept here as a record.
It is the 15th strongest of the 31 detections recorded within 20 km of this point since 16 March 2026. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued March 15 at 9:31PM EDT until March 15 at 10:30PM EDT by NWS Jacksonville FL
An estimated 34,125 people live within 50 km of this point.
Nearby, since 16 March 2026
- August 28, 2026 · score 39 · 5.3 km
- July 29, 2026 · score 39 · 10.6 km
- June 15, 2026 · score 39 · 11.0 km
How we know
Confirmed by 6 independent sources, including NOAA.
Our own score for this event is 34 out of 100, at 87 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 34 / 100 |
| Our confidence | 87% |
| Coordinates | 30.8516, -81.1254 |
| Nearest City | St. Marys (43 km) |
| Population Exposed | 34.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-16T01:31:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.a33c0f02a2c148ac61207df0e48fe45b |
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 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 |
| Headline | Special Marine Warning issued March 15 at 9:31PM EDT until March 15 at 10:30PM EDT by NWS Jacksonville FL |
| Expires | 2026-03-15T22:30:00-04:00 |
| SenderName | NWS Jacksonville FL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.a33c0f02a2c148ac61207df0e48fe45b74af9a83.001.1","noaa_urn:oid:2.49.0.1.840.0.6d4ca4b05fcdc1a405afcba3d2dd534c59103fd4.001.1","noaa_urn:oid:2.49.0.1.840.0.6341a4808c19fcc5fd5f542924cafde4fea43ef4.001.1"] |
| Iem TypeSummary | M |
| Iem Magnitude | 40 |
| Iem Unit | MPH |
| Iem City | 1 NNE Jacksonville Beac |
| Iem County | AMZ452 |
| Iem State | FL |
| Iem Wfo | JAX |
| Iem Remark | Mesonet station 1618W Fswn Jacksonville Beach. |
| MergedSources | [{"id":"iem_G_30.620_-81.470_1773622500000","source":"iem","severity":"low","severityValue":25,"timestamp":1773622500000,"latitude":30.62,"longitude":-81.47},{"id":"iem_G_30.380_-81.420_1773620280000","source":"iem","severity":"low","severityValue":25,"timestamp":1773620280000,"latitude":30.38,"longitude":-81.42},{"id":"iem_M_30.290_-81.390_1773621000000","source":"iem","severity":"low","severityValue":25,"timestamp":1773621000000,"latitude":30.29,"longitude":-81.39},{"id":"iem_G_30.340_-81.630_1773621780000","source":"iem","severity":"low","severityValue":25,"timestamp":1773621780000,"latitude":30.34,"longitude":-81.63},{"id":"iem_M_30.290_-81.390_1773620400000","source":"iem","severity":"low","severityValue":25,"timestamp":1773620400000,"latitude":30.29,"longitude":-81.39}] |
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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 34/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.