This alert expired on 21 June 2026 at 23:30 UTC. It is kept here as a record.
No stronger detection stands among the 25 recorded within 20 km of this point since 31 May 2026 — 15 others scored the same. The last comparable one was on 18 June 2026. 10 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued June 21 at 5:55PM EDT until June 21 at 7:30PM EDT by NWS Charleston SC
An estimated 162,918 people live within 50 km of this point.
Nearby, since 31 May 2026
- June 18, 2026 · score 43 · 3.7 km
- June 29, 2026 · score 43 · 7.2 km
- June 15, 2026 · score 43 · 7.4 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 84 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 84% |
| Coordinates | 31.6900, -81.0476 |
| Nearest City | Wilmington Island (35 km) |
| Population Exposed | 162.9K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-21T21:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.536000e74585a7242b9bf5a5b0b98d24 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | 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; Waters from Savannah GA to Altamaha Sound GA extending from 20 to 60 NM; 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 |
| Headline | Special Marine Warning issued June 21 at 5:55PM EDT until June 21 at 7:30PM EDT by NWS Charleston SC |
| Expires | 2026-06-21T19:30:00-04:00 |
| SenderName | NWS Charleston SC |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.536000e74585a7242b9bf5a5b0b98d24b54faef8.001.1","noaa_urn:oid:2.49.0.1.840.0.f26585ca2107cf57b2a860ec8da31dc982be7d89.001.1"] |
| Iem TypeSummary | M |
| Iem Magnitude | 43 |
| Iem Unit | mph |
| Iem City | 2 NW Sapelo Island |
| Iem County | McIntosh |
| Iem State | GA |
| Iem Wfo | CHS |
| Iem Remark | The Sapelo Island observation site measured a wind gust of 37 knots. |
| MergedSources | [{"id":"iem_M_31.420_-81.300_1782075600000","source":"iem","severity":"low","severityValue":25,"timestamp":1782075600000,"latitude":31.42,"longitude":-81.3}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.