Right now
The most recent data we hold from NOAA arrived 11 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 18 June 2026 at 22:00 UTC. It is kept here as a record.
It is the 9th strongest of the 35 detections recorded within 20 km of this point since 16 March 2026. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 18 at 5:17PM EDT until June 18 at 6:00PM EDT by NWS Jacksonville FL
Urban PEI: 16,157 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- July 29, 2026 · score 39 · 13.1 km
- June 15, 2026 · score 39 · 15.3 km
- September 12, 2026 · score 16 · 15.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 34 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 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 |
| Legacy data-support index | 0.78/1 |
| Coordinates | 31.0255, -81.1098 |
| Nearest City | Brunswick (39 km) |
| Urban exposure index (PEI) | 16.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-18T21:17:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.ceb277f2c46605eba906b25b746ab45f |
Physical priority index · v1. 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: 2026-06-18T21:17:00.000Z.
First archived: 2026-06-18T21:21:33.618Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM; Coastal waters from St. Augustine to Flagler Beach FL out 20 NM; Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM; Coastal waters from Edisto Beach SC to Savannah GA out 20 NM; Coastal waters from Savannah GA to Altamaha Sound GA out 20 nm, including Grays Reef National Marine Sanctuary |
| Headline | Special Marine Warning issued June 18 at 5:17PM EDT until June 18 at 6:00PM EDT by NWS Jacksonville FL |
| Expires | 2026-06-18T18:00:00-04:00 |
| SenderName | NWS Jacksonville FL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ceb277f2c46605eba906b25b746ab45fff73664a.001.1","noaa_urn:oid:2.49.0.1.840.0.e01aa7646976c3fc06c1b676ca06c6cb5b96c174.001.1","noaa_urn:oid:2.49.0.1.840.0.ef895a5666373bec25d2f4fdaf3833b1eb05a5c0.001.1"] |
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.
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