Right now
The most recent data we hold from NOAA arrived 1 minute 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 19 May 2026 at 22:45 UTC. It is kept here as a record.
It is one of only 3 we have recorded within 20 km of this point since 19 May 2026.
What the source measured
NOAA reported: Special Marine Warning issued May 19 at 5:51PM EDT until May 19 at 6:45PM EDT by NWS Boston/Norton MA
Nearby, since 19 May 2026
- August 9, 2026 · score 34 · 16.2 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
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 | 0.66/1 |
| Coordinates | 42.7534, -69.9647 |
| Nearest City | Gloucester (59 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-05-19T21:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.c9a3d7af2f8e79df44bf48c6f9721bac |
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: 2026-05-19T21:51:00.000Z.
First archived: 2026-05-19T22:12:13.884Z. 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 | Boston Harbor; Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary; Massachusetts Bay and Ipswich Bay; Ocean Waters from the Merrimack River to Plymouth from 40 to 60 NM; Coastal Waters from Cape Elizabeth, ME to Merrimack River, MA out 25 NM; Waters from Stonington ME to Port Clyde ME from 25 to 60 NM; Waters from Port Clyde ME to Cape Elizabeth ME from 25 to 60 NM; Waters from Cape Elizabeth ME to Merrimack River MA from 25 to 60 NM |
| Headline | Special Marine Warning issued May 19 at 5:51PM EDT until May 19 at 6:45PM EDT by NWS Boston/Norton MA |
| Expires | 2026-05-19T18:45:00-04:00 |
| SenderName | NWS Boston/Norton MA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c9a3d7af2f8e79df44bf48c6f9721baca5478fee.001.1","noaa_urn:oid:2.49.0.1.840.0.f7b85564c6c84e630d39fa718a78def1655f4f68.001.1"] |
| Iem TypeSummary | M |
| Iem Magnitude | 63 |
| Iem Unit | MPH |
| Iem City | 8 ESE Rye |
| Iem County | ANZ154 |
| Iem State | NH |
| Iem Wfo | GYX |
| Iem Remark | Appledore Island. |
| MergedSources | [{"id":"iem_M_42.970_-70.620_1779225540000","source":"iem","severity":"low","severityValue":25,"timestamp":1779225540000,"latitude":42.97,"longitude":-70.62}] |
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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