This alert expired on 21 May 2026 at 00:15 UTC. It is kept here as a record.
No stronger detection stands among the 141 recorded within 20 km of this point since 12 March 2026 — 99 others scored the same. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 20 at 6:17PM EDT until May 20 at 8:15PM EDT by NWS Mount Holly NJ
An estimated 3,389,520 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 21, 2026 · score 46 · 5.0 km
- March 17, 2026 · score 52 · 10.4 km
- July 6, 2026 · score 52 · 10.5 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 85 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 85% |
| Coordinates | 39.7327, -74.8163 |
| Nearest City | Jackson (6 km) |
| Population Exposed | 3.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T22:17:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.b0801c509d818908f06ce84065782625 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 NM; Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 NM; Waters from Sandy Hook NJ to Manasquan Inlet NJ from 20 to 40 NM; Waters from Manasquan Inlet NJ to Little Egg Inlet NJ from 20 to 60 NM; Long Island Sound East of New Haven CT/Port Jefferson NY to the Mouth of the Connecticut River; Long Island Sound West of New Haven CT/Port Jefferson NY; Delaware Bay waters north of East Point NJ to Slaughter Beach DE; Delaware Bay waters south of East Point NJ to Slaughter Beach DE; 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 and 2 more areas |
| Headline | Special Marine Warning issued May 20 at 6:17PM EDT until May 20 at 8:15PM EDT by NWS Mount Holly NJ |
| Expires | 2026-05-20T20:15:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b0801c509d818908f06ce840657826251d9d0072.001.1","noaa_urn:oid:2.49.0.1.840.0.3839fab2878b78e57e0a6974ce2e47447dbc3788.001.1","noaa_urn:oid:2.49.0.1.840.0.48031688f0c4e6a8c287d6c664de9669310c072b.001.1","noaa_urn:oid:2.49.0.1.840.0.9d62057f8aa441ae88d62ea094a5574d3e5be33a.001.1","noaa_urn:oid:2.49.0.1.840.0.48ed17875a240dbfb7fef92f61d57eb197547fc8.002.1"] |
| Iem TypeSummary | D |
| Iem City | 1 SSE Hainesport |
| Iem County | Burlington |
| Iem State | NJ |
| Iem Wfo | PHI |
| Iem Remark | Wires down in Hainesport along Marne Highway, likely due to outflow boundary. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_39.980_-74.820_1779314700000","source":"iem","severity":"low","severityValue":25,"timestamp":1779314700000,"latitude":39.98,"longitude":-74.82}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Jackson (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.