This alert expired on 22 June 2026 at 21:00 UTC. It is kept here as a record.
It is the 4th strongest of the 155 detections recorded within 20 km of this point since 17 March 2026. Another comparable one was recorded here earlier the same day. 8 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued June 22 at 4:35PM EDT until June 22 at 5:00PM EDT by NWS Mount Holly NJ
An estimated 629,910 people live within 50 km of this point.
Nearby, since 17 March 2026
- June 22, 2026 · score 43 · 8.0 km
- June 22, 2026 · score 76 · 14.3 km
- August 31, 2026 · score 48 · 14.9 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 72 out of 100, at 82 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | critical |
| Calamity Score (ours) | 72 / 100 |
| Our confidence | 82% |
| Coordinates | 40.0938, -75.8050 |
| Nearest City | Pottstown (22 km) |
| Population Exposed | 629.9K within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-06-22T20:35:00.000Z |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Berks, PA; Chester, PA; Delaware, PA; Montgomery, PA |
| Headline | Tornado Warning issued June 22 at 4:35PM EDT until June 22 at 5:00PM EDT by NWS Mount Holly NJ |
| Expires | 2026-06-22T17:00:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| Iem TypeSummary | D |
| Iem City | Holmesburg |
| Iem County | Philadelphia |
| Iem State | PA |
| Iem Wfo | PHI |
| Iem Remark | Multiple large tree branches and a tree snapped. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_40.040_-75.030_1782152640000","source":"iem","severity":"low","severityValue":25,"timestamp":1782152640000,"latitude":40.04,"longitude":-75.03}] |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 72/100, near Pottstown (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.