Right now
The most recent data we hold from NOAA arrived 42 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 23:54 UTC. It is kept here as a record.
It is the 4th strongest of the 14 detections recorded within 20 km of this point since 16 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 June 18 at 7:44PM EDT until June 18 at 7:45PM EDT by NWS Charleston SC
Nearby, since 16 March 2026
- June 18, 2026 · score 22 · 18.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 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) | 22 / 100 |
| Legacy data-support index | 0.59/1 |
| Coordinates | 30.5949, -80.8921 |
| Nearest City | Jacksonville Beach (59 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Date | 2026-06-18 — time not reported by the source |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.998196c94c31367780644e9fb3b23a3f |
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: 2026-06-18 — time not reported.
First archived: 2026-06-18T23:45:21.564Z. 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 Savannah GA to Altamaha Sound GA out 20 nm, including Grays Reef National Marine Sanctuary; Coastal waters from Savannah GA to Altamaha Sound GA out 20 nm, including Grays Reef National Marine Sanctuary; Waters from Savannah GA to Altamaha Sound GA extending from 20 to 60 NM; Waters from Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM and 2 more areas |
| Headline | Special Marine Warning issued June 18 at 7:44PM EDT until June 18 at 7:45PM EDT by NWS Charleston SC |
| Expires | 2026-06-18T19:54:00-04:00 |
| SenderName | NWS Charleston SC |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.998196c94c31367780644e9fb3b23a3fd5b16f45.001.1","noaa_urn:oid:2.49.0.1.840.0.6aac252440ce7d22fa29fa7191bf07492eba3218.001.1","noaa_urn:oid:2.49.0.1.840.0.f3c9ac252cf3680d230fa0b3397ccd4c19e8581b.001.1","noaa_urn:oid:2.49.0.1.840.0.187360f03fdbea368464ffd031839dc373a583c1.001.1","noaa_urn:oid:2.49.0.1.840.0.7d71dea5e9a5aaa0e607c28e7866bdbd11d2e517.001.1"] |
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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