This alert expired on 4 September 2026 at 10:00 UTC. It is kept here as a record.
It is the 2nd strongest of the 5 detections recorded within 20 km of this point since 5 July 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 4 at 4:57AM EDT until September 4 at 6:00AM EDT by NWS Boston/Norton MA
Nearby, since 5 July 2026
- July 5, 2026 · score 22 · 9.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 16 out of 100, at 61 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 16 / 100 |
| Our confidence | 61% |
| Coordinates | 40.8820, -70.8280 |
| Nearest City | Newport (79 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-04T08:57:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.1a6be84a905523d2631c09543affbd9abe7bef27.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Coastal Waters extending out to 25 NM South of Marthas Vineyard and Nantucket; Ocean Waters from Marthas Vineyard to Nantucket from 25 to 60 NM; Rhode Island Sound; Block Island Sound; Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 NM South of Block Island; Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 NM South of Block Island; Ocean Waters from Montauk NY to Marthas Vineyard from 25 to 60 NM |
| Headline | Special Marine Warning issued September 4 at 4:57AM EDT until September 4 at 6:00AM EDT by NWS Boston/Norton MA |
| Expires | 2026-09-04T06:00:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1a6be84a905523d2631c09543affbd9abe7bef27.001.1","noaa_urn:oid:2.49.0.1.840.0.f8eb882f2a442f4198563dd7afd4b9aa24c5159f.001.1","noaa_urn:oid:2.49.0.1.840.0.e8787617c8e466064928f0877691327c4d840e7d.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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 16/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.