Right now
The most recent data we hold from NOAA arrived 14 minutes 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 15 September 2026 at 19:30 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 3 April 2026. The last comparable one was on 12 September 2026. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued September 15 at 2:34PM AST until September 15 at 3:30PM AST by NWS San Juan PR
Urban PEI: 89,150 within a heuristic 50 km radius; not unique people.
Nearby, since 3 April 2026
- June 29, 2026 · score 43 · 11.8 km
- September 12, 2026 · score 37 · 13.7 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.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v5. 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 |
| Legacy data-support index | 0.81/1 |
| Coordinates | 18.1962, -67.3319 |
| Nearest City | Mayagüez (20 km) |
| Urban exposure index (PEI) | 89.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-15T18:34:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.bae9472b749422e9609df7870f8b548c54338c28.001.1 |
Physical priority index · v5. 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: 2026-09-15T18:34:00.000Z.
First archived: 2026-09-15T18:42:05.007Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-15T18:53:12.136Z · data_change
Index 32 → 32; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Mona Passage Southward to 17N; Coastal Waters OF Northwestern Puerto Rico out 10 NM; Coastal Waters OF Southwestern Puerto Rico out 10 NM |
| Headline | Special Marine Warning issued September 15 at 2:34PM AST until September 15 at 3:30PM AST by NWS San Juan PR |
| Expires | 2026-09-15T15:30:00-04:00 |
| SenderName | NWS San Juan PR |
| 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.
Review the area, threshold and delivery channel in your account.
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