This alert expired on 13 August 2026 at 19:30 UTC. It is kept here as a record.
It is the 4th strongest of the 5 detections recorded within 20 km of this point since 2 July 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 August 13 at 2:37PM EDT until August 13 at 3:30PM EDT by NWS Boston/Norton MA
An estimated 88,123 people live within 50 km of this point.
Nearby, since 2 July 2026
- August 13, 2026 · score 43 · 24.3 km
- July 2, 2026 · score 39 · 24.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 39 out of 100, at 78 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 39 / 100 |
| Our confidence | 78% |
| Coordinates | 41.8911, -70.2278 |
| Nearest City | Yarmouth (20 km) |
| Population Exposed | 88.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-13T18:37:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.819533092acd98689ba8fe3ce911294c0f4b9b53.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Cape Cod Bay; Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary; Massachusetts Bay and Ipswich Bay |
| Headline | Special Marine Warning issued August 13 at 2:37PM EDT until August 13 at 3:30PM EDT by NWS Boston/Norton MA |
| Expires | 2026-08-13T15:30:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
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 near Yarmouth?
Calamity.live data shows a weather event with CalamityScore 39/100, near Yarmouth (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.