This alert expired on 16 March 2026 at 02:45 UTC. It is kept here as a record.
It is the 6th strongest of the 33 detections recorded within 20 km of this point since 8 March 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued March 15 at 9:54PM EDT until March 15 at 10:45PM EDT by NWS Jacksonville FL
An estimated 50,612 people live within 50 km of this point.
Nearby, since 8 March 2026
- July 8, 2026 · score 39 · 3.3 km
- June 15, 2026 · score 39 · 9.0 km
- August 28, 2026 · score 39 · 11.3 km
How we know
Confirmed by 13 independent sources, including NOAA.
Our own score for this event is 39 out of 100, at 88 % 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) | 39 / 100 |
| Our confidence | 88% |
| Coordinates | 30.8454, -81.2833 |
| Nearest City | St. Marys (29 km) |
| Population Exposed | 50.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-16T01:54:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.29beb0f3ac797f82ee94fd1e3843442f |
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 Altamaha Sound to Fernandina Beach FL out 20 NM |
| Headline | Special Marine Warning issued March 15 at 9:54PM EDT until March 15 at 10:45PM EDT by NWS Jacksonville FL |
| Expires | 2026-03-15T22:45:00-04:00 |
| SenderName | NWS Jacksonville FL |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.29beb0f3ac797f82ee94fd1e3843442f27074218.001.1","noaa_urn:oid:2.49.0.1.840.0.a33c0f02a2c148ac61207df0e48fe45b74af9a83.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 40 |
| Iem Unit | MPH |
| Iem City | 1 SE Jacksonville |
| Iem County | Duval |
| Iem State | FL |
| Iem Wfo | JAX |
| Iem Remark | Mesonet station 1562W Fpr Wjct Jacksonville. |
| 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_30.320_-81.640_1773625200000","source":"iem","severity":"low","severityValue":25,"timestamp":1773625200000,"latitude":30.32,"longitude":-81.64},{"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_M_30.390_-81.440_1773626400000","source":"iem","severity":"low","severityValue":25,"timestamp":1773626400000,"latitude":30.39,"longitude":-81.44},{"id":"iem_G_30.340_-81.630_1773621780000","source":"iem","severity":"low","severityValue":25,"timestamp":1773621780000,"latitude":30.34,"longitude":-81.63},{"id":"iem_G_31.050_-81.410_1773623880000","source":"iem","severity":"low","severityValue":25,"timestamp":1773623880000,"latitude":31.05,"longitude":-81.41},{"id":"iem_G_30.330_-81.520_1773625980000","source":"iem","severity":"low","severityValue":25,"timestamp":1773625980000,"latitude":30.33,"longitude":-81.52},{"id":"iem_M_31.400_-80.870_1773623400000","source":"iem","severity":"low","severityValue":25,"timestamp":1773623400000,"latitude":31.4,"longitude":-80.87},{"id":"iem_G_30.500_-81.680_1773626160000","source":"iem","severity":"low","severityValue":25,"timestamp":1773626160000,"latitude":30.5,"longitude":-81.68},{"id":"iem_M_30.290_-81.390_1773620400000","source":"iem","severity":"low","severityValue":25,"timestamp":1773620400000,"latitude":30.29,"longitude":-81.39},{"id":"iem_G_30.320_-81.640_1773621600000","source":"iem","severity":"low","severityValue":25,"timestamp":1773621600000,"latitude":30.32,"longitude":-81.64}] |
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 near St. Marys?
Calamity.live data shows a weather event with CalamityScore 39/100, near St. Marys (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.