Right now
The most recent data we hold from NOAA arrived 25 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 19 July 2026 at 00:30 UTC. It is kept here as a record.
It is the 2nd strongest of the 41 detections recorded within 20 km of this point since 17 March 2026. Another comparable one was recorded here earlier the same day. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 18 at 6:30PM EDT until July 18 at 8:30PM EDT by NWS Mount Holly NJ
Urban PEI: 150,786 within a heuristic 50 km radius; not unique people.
Nearby, since 17 March 2026
- July 27, 2026 · score 43 · 4.8 km
- August 3, 2026 · score 37 · 10.2 km
- September 2, 2026 · score 32 · 12.3 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 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) | 43 / 100 |
| Legacy data-support index | 0.79/1 |
| Coordinates | 39.0261, -75.1928 |
| Nearest City | Dover (32 km) |
| Urban exposure index (PEI) | 150.8K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-18T22:30:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.e73c0bb4f95262f081d9d24bba30e3c1 |
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: 2026-07-18T22:30:00.000Z.
First archived: 2026-07-18T22:36:56.399Z. 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 | Delaware Bay waters south of East Point NJ to Slaughter Beach DE; Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 NM; Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 NM; Coastal waters from Great Egg Inlet to Cape May NJ out 20 NM; Coastal waters from Cape May NJ to Cape Henlopen DE out 20 NM; Coastal waters from Cape Henlopen to Fenwick Island DE out 20 NM; Waters from Manasquan Inlet NJ to Little Egg Inlet NJ from 20 to 60 NM; Waters from Little Egg Inlet NJ to Great Egg Inlet NJ from 20 to 60 NM; Waters from Great Egg Inlet NJ to Cape May NJ from 20 to 60 NM; Waters from Cape May NJ to Fenwick Island DE from 20 to 60 NM; Chesapeake Bay from North Beach to Drum Point MD; Chesapeake Bay from Drum Point MD to Smith Point VA; Tidal Potomac from Cobb Island MD to Smith Point VA; Patuxent River to Broomes Island MD; Tangier Sound and the inland waters surrounding Bloodsworth Island; Chesapeake Bay from North Beach to Drum Point MD; Chesapeake Bay from Drum Point MD to Smith Point VA; Choptank River to Cambridge MD and the Little Choptank River; Patuxent River to Broomes Island MD; Tangier Sound and the inland waters surrounding Bloodsworth Island and 2 more areas |
| Headline | Special Marine Warning issued July 18 at 6:30PM EDT until July 18 at 8:30PM EDT by NWS Mount Holly NJ |
| Expires | 2026-07-18T20:30:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e73c0bb4f95262f081d9d24bba30e3c1661f4f34.001.1","noaa_urn:oid:2.49.0.1.840.0.921f850b7491a33f593cd533512eee065a51f35a.001.1","noaa_urn:oid:2.49.0.1.840.0.34e75175e2b2778ca041d139fc41b5b950453620.001.1","noaa_urn:oid:2.49.0.1.840.0.60c9992bd3e9e5dc10d088be0ce218f6af6a5ac3.001.1","noaa_urn:oid:2.49.0.1.840.0.740605d30fc3cbb1a54cb70e9428769ab1d0640b.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.
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