This alert expired on 2 September 2026 at 01:45 UTC. It is kept here as a record.
No stronger detection stands among the 252 recorded within 20 km of this point since 12 March 2026 — 6 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 1 at 8:23PM EDT until September 1 at 9:45PM EDT by NWS Mount Holly NJ
An estimated 3,138,365 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 6, 2026 · score 52 · 3.1 km
- September 2, 2026 · score 58 · 3.7 km
- July 9, 2026 · score 52 · 3.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 58 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 | high |
| Calamity Score (ours) | 58 / 100 |
| Our confidence | 85% |
| Coordinates | 39.6062, -75.1573 |
| Nearest City | Glassboro (11 km) |
| Population Exposed | 3.1M within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-09-02T00:23:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.7f1df90d928748e0ad251825f96ef07e972e3dc8.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Delaware Bay waters north of East Point NJ to Slaughter Beach DE; Chesapeake Bay north of Pooles Island MD; 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 Manasquan Inlet NJ to Little Egg Inlet NJ from 20 to 60 NM |
| Headline | Special Marine Warning issued September 1 at 8:23PM EDT until September 1 at 9:45PM EDT by NWS Mount Holly NJ |
| Expires | 2026-09-01T21:45:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.7f1df90d928748e0ad251825f96ef07e972e3dc8.001.1","noaa_urn:oid:2.49.0.1.840.0.4338fc8adbc87c59dfd875ac0e0a97ca68f72cbd.001.1","noaa_urn:oid:2.49.0.1.840.0.0e4fe796e87ef12b9817aa6d115f9fe3d726b35d.001.1"] |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | Williamstown |
| Spc County | Gloucester |
| Spc State | NJ |
| Spc Comments | Quarter size hail reported in Williamstown. (PHI) |
| MergedSources | [{"id":"spc_hail_39.69_-74.99_61","source":"spc","severity":"high","severityValue":65,"timestamp":1788308880000,"latitude":39.69,"longitude":-74.99}] |
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.
Want to know when something happens near Glassboro?
Calamity.live data shows a weather event with CalamityScore 58/100, near Glassboro (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.