This alert expired on 3 September 2026 at 09:15 UTC. It is kept here as a record.
It is the 2nd strongest of the 14 detections recorded within 20 km of this point since 11 June 2026. The last comparable one was on 2 September 2026.
What the source measured
NOAA reported: Flash Flood Warning issued September 3 at 1:09AM EDT until September 3 at 5:15AM EDT by NWS State College PA
An estimated 29,201 people live within 50 km of this point.
Nearby, since 11 June 2026
- August 3, 2026 · score 34 · 18.2 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 93 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 28 / 100 |
| Our confidence | 93% |
| Coordinates | 40.8741, -76.8456 |
| Nearest City | Williamsport (43 km) |
| Population Exposed | 29.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T05:09:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.dd2aba83825985cc73cd0332d8bf5be643c0372d.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Clinton, PA; Lycoming, PA; Dauphin, PA; Lebanon, PA; Schuylkill, PA; Northumberland, PA; Snyder, PA; Union, PA |
| Headline | Flash Flood Warning issued September 3 at 1:09AM EDT until September 3 at 5:15AM EDT by NWS State College PA |
| Expires | 2026-09-03T05:15:00-04:00 |
| SenderName | NWS State College PA |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.dd2aba83825985cc73cd0332d8bf5be643c0372d.001.1","noaa_urn:oid:2.49.0.1.840.0.39756a3debbad783c077e8ad593789cc5dfcd85d.001.1","noaa_urn:oid:2.49.0.1.840.0.ef56cdd120bcd8c805e968dc686010ffbacf6435.001.1"] |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | 2 ENE Loysville |
| Spc County | Perry |
| Spc State | PA |
| Spc Comments | Tree down at Mahanoy Ridge Road near the intersection of Shermans Valley Road. (CTP) |
| Iem TypeSummary | F |
| Iem City | 1 NE Mechanicsville |
| Iem County | Montour |
| Iem State | PA |
Safety Information
During flooding: never walk, swim, or drive through floodwaters. Six inches of moving water can knock you down, and one foot of water can sweep away a vehicle. Move to higher ground if waters rise. After flooding, avoid contact with floodwater which may contain sewage, chemicals, or debris. Follow local emergency service guidance.
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 in this area?
Calamity.live data shows a weather event with CalamityScore 28/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.