This alert expired on 3 September 2026 at 07:30 UTC. It is kept here as a record.
No stronger detection stands among the 13 recorded within 20 km of this point since 17 March 2026 — 3 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Flash Flood Warning issued September 2 at 11:26PM EDT until September 3 at 3:30AM EDT by NWS State College PA
An estimated 29,201 people live within 50 km of this point.
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 87 % 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 | 87% |
| Coordinates | 41.4808, -77.4932 |
| Nearest City | Williamsport (49 km) |
| Population Exposed | 29.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T03:26:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.ef56cdd120bcd8c805e968dc686010ffbacf6435.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Northumberland, PA; Snyder, PA; Union, PA; Centre, PA; Clinton, PA; Lycoming, PA; Union, PA; Allegany, NY; Cattaraugus, NY and 2 more areas |
| Headline | Flash Flood Warning issued September 2 at 11:26PM EDT until September 3 at 3:30AM EDT by NWS State College PA |
| Expires | 2026-09-03T03:30:00-04:00 |
| SenderName | NWS State College PA |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ef56cdd120bcd8c805e968dc686010ffbacf6435.001.1","noaa_urn:oid:2.49.0.1.840.0.95564d66dd9292d422cc97796927fe28d77c7a07.001.1","noaa_urn:oid:2.49.0.1.840.0.77c092015c810e01a43340a2b55dd75971b4be57.001.1","noaa_urn:oid:2.49.0.1.840.0.bcd4213e3662135db456e5511fccb37eb34e1e5e.001.1","noaa_urn:oid:2.49.0.1.840.0.707d1ec229b4b7d228402abed115e09674013cc0.001.1"] |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | 5 N Denton Hill State P |
| Spc County | Potter |
| Spc State | PA |
| Spc Comments | Tree down partially blocking South Brookland Road. Likely associated with the outflow boundary out ahead of the line of storms. (CTP) |
| MergedSources | [{"id":"spc_wind_41.95_-77.89_214","source":"spc","severity":"medium","severityValue":45,"timestamp":1788397800000,"latitude":41.95,"longitude":-77.89},{"id":"spc_wind_41.83_-77.80_215","source":"spc","severity":"medium","severityValue":45,"timestamp":1788398700000,"latitude":41.83,"longitude":-77.8}] |
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.