Right now
The most recent data we hold from NOAA arrived 2 hours 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 20 May 2026 at 21:30 UTC. It is kept here as a record.
No stronger detection stands among the 100 recorded within 20 km of this point since 12 March 2026 — 23 others scored the same. The last comparable one was on 17 March 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 20 at 4:46PM EDT until May 20 at 5:30PM EDT by NWS Mount Holly NJ
An estimated 1,239,996 people live within 50 km of this point.
Nearby, since 12 March 2026
- July 1, 2026 · score 52 · 1.8 km
- July 29, 2026 · score 46 · 2.3 km
- August 7, 2026 · score 52 · 8.6 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 52 / 100 |
| Our confidence | 90% |
| Coordinates | 40.4439, -75.2251 |
| Nearest City | Lansdale (23 km) |
| Population Exposed | 1.2M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-20T20:46:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.98e25e7f69ca8d83252a753b71687388 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Berks, PA; Bucks, PA; Lehigh, PA; Montgomery, PA; Hunterdon, NJ; Warren, NJ; Berks, PA; Bucks, PA; Lehigh, PA; Northampton, PA; Lancaster, PA and 2 more areas |
| Headline | Severe Thunderstorm Warning issued May 20 at 4:46PM EDT until May 20 at 5:30PM EDT by NWS Mount Holly NJ |
| Expires | 2026-05-20T17:30:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.98e25e7f69ca8d83252a753b71687388f4a2682b.001.1","noaa_urn:oid:2.49.0.1.840.0.6f5a485635b8674adfd2e57e706a6c94cb21d12e.001.1","noaa_urn:oid:2.49.0.1.840.0.57c9f1f69174f7186e90828a17aa4a3dd04db8cb.001.1","noaa_urn:oid:2.49.0.1.840.0.ca227f2613d9ef061105816507d5a5ae6aa30bd4.001.1","noaa_urn:oid:2.49.0.1.840.0.0ab05cd5869e39cbee5a9f29a40a3594d4db6a06.001.1"] |
| Iem TypeSummary | D |
| Iem City | 3 SSE Kenhorst |
| Iem County | Berks |
| Iem State | PA |
| Iem Wfo | PHI |
| Iem Remark | Trees down on wires along Mount Penn Road. Time estimated from radar. |
| MergedSources | [{"id":"iem_D_40.540_-75.760_1779309180000","source":"iem","severity":"low","severityValue":25,"timestamp":1779309180000,"latitude":40.54,"longitude":-75.76},{"id":"iem_D_40.550_-76.000_1779308100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779308100000,"latitude":40.55,"longitude":-76},{"id":"iem_D_40.260_-75.930_1779308040000","source":"iem","severity":"low","severityValue":25,"timestamp":1779308040000,"latitude":40.26,"longitude":-75.93},{"id":"iem_D_40.270_-75.930_1779308100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779308100000,"latitude":40.27,"longitude":-75.93}] |
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.
Want to know when something happens near Lansdale?