This alert expired on 4 September 2026 at 10:45 UTC. It is kept here as a record.
It is the 4th strongest of the 23 detections recorded within 20 km of this point since 17 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 4 at 5:38AM EDT until September 4 at 6:45AM EDT by NWS Boston/Norton MA
An estimated 88,229 people live within 50 km of this point.
Nearby, since 17 March 2026
- September 4, 2026 · score 32 · 7.4 km
- July 5, 2026 · score 39 · 10.5 km
- September 4, 2026 · score 37 · 14.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 32 out of 100, at 82 % 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) | 32 / 100 |
| Our confidence | 82% |
| Coordinates | 41.1290, -71.1480 |
| Nearest City | Newport (42 km) |
| Population Exposed | 88.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T09:38:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.5699bd208ab0c7a3417dfc4b0857157f134417e7.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Rhode Island Sound; Coastal Waters extending out to 25 NM South of Marthas Vineyard and Nantucket; Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 NM South of Block Island; Ocean Waters from Marthas Vineyard to Nantucket from 25 to 60 NM; Ocean Waters from Montauk NY to Marthas Vineyard 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 |
| Headline | Special Marine Warning issued September 4 at 5:38AM EDT until September 4 at 6:45AM EDT by NWS Boston/Norton MA |
| Expires | 2026-09-04T06:45:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.5699bd208ab0c7a3417dfc4b0857157f134417e7.001.1","noaa_urn:oid:2.49.0.1.840.0.f8eb882f2a442f4198563dd7afd4b9aa24c5159f.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 32/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.