Right now
The most recent data we hold from NOAA arrived 10 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 23:05 UTC. It is kept here as a record.
It is the 5th strongest of the 17 detections recorded within 20 km of this point since 16 March 2026. Another comparable one was recorded here earlier the same day. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 18 at 6:55PM EDT until June 18 at 7:00PM EDT by NWS Charleston SC
Nearby, since 16 March 2026
- June 18, 2026 · score 22 · 11.2 km
- June 21, 2026 · score 22 · 18.7 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 | 30.7048, -80.8790 |
| Nearest City | St. Marys (64 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-06-18T22:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.e1adbc0aaa60cee82666249fdd16a64e |
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: 2026-06-18T22:55:00.000Z.
First archived: 2026-06-18T22:57:33.739Z. 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 | Charleston Harbor; Coastal waters from South Santee River to Edisto Beach SC 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; Coastal waters from Altamaha Sound to Fernandina Beach FL out 20 NM; Coastal waters from Fernandina Beach to St. Augustine FL out 20 NM and 4 more areas |
| Headline | Special Marine Warning issued June 18 at 6:55PM EDT until June 18 at 7:00PM EDT by NWS Charleston SC |
| Expires | 2026-06-18T19:05:00-04:00 |
| SenderName | NWS Charleston SC |
| HasExactCoords | true |
| MergedCount | 8 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e1adbc0aaa60cee82666249fdd16a64e3269de17.001.1","noaa_urn:oid:2.49.0.1.840.0.1ddc6e90d77de969024f0ac82331176bb000e025.001.1","noaa_urn:oid:2.49.0.1.840.0.bd3951dce7d7634a935d9c83f8bc0de7b9869d1f.001.1","noaa_urn:oid:2.49.0.1.840.0.010eea4c4aea7c7c3e14ebccd3bbd86441ee9cca.001.1","noaa_urn:oid:2.49.0.1.840.0.5d4393d0913ee6a8339598653d276da22318e813.001.1","noaa_urn:oid:2.49.0.1.840.0.d03f9aaea14c0444d4a736f803e82181de43bc7e.001.1","noaa_urn:oid:2.49.0.1.840.0.187360f03fdbea368464ffd031839dc373a583c1.001.1","noaa_urn:oid:2.49.0.1.840.0.7037d52e0e54d7ae50d4578e33c0652afd74692d.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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