This alert expired on 11 August 2026 at 12:30 UTC. It is kept here as a record.
It is the 2nd strongest of the 27 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: Flash Flood Warning issued August 11 at 6:07AM EDT until August 11 at 8:30AM EDT by NWS State College PA
An estimated 40,096 people live within 50 km of this point.
Nearby, since 17 March 2026
- June 22, 2026 · score 22 · 15.8 km
- June 22, 2026 · score 46 · 20.6 km
How we know
Confirmed by 7 independent sources, including NOAA.
Our own score for this event is 34 out of 100, at 92 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 34 / 100 |
| Our confidence | 92% |
| Coordinates | 39.9609, -79.1419 |
| Nearest City | Johnstown (45 km) |
| Population Exposed | 40.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-11T10:07:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.8cbef5aca1efecba469b473633ca1d34 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Somerset, PA |
| Headline | Flash Flood Warning issued August 11 at 6:07AM EDT until August 11 at 8:30AM EDT by NWS State College PA |
| Expires | 2026-08-11T08:30:00-04:00 |
| SenderName | NWS State College PA |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.8cbef5aca1efecba469b473633ca1d34aca4b02c.001.1","noaa_urn:oid:2.49.0.1.840.0.2b90265516e80d45462bd1f82c2da8acd39af925.001.1"] |
| Iem TypeSummary | F |
| Iem City | 1 S Rockwood |
| Iem County | Somerset |
| Iem State | PA |
| Iem Wfo | CTP |
| Iem Remark | Rockdale Road flooded and impassable. 12 to 14 inch rocks washed across the road being removed. |
| MergedSources | [{"id":"iem_D_39.690_-79.170_1786424580000","source":"iem","severity":"low","severityValue":25,"timestamp":1786424580000,"latitude":39.69,"longitude":-79.17},{"id":"iem_F_39.940_-79.260_1786443000000","source":"iem","severity":"low","severityValue":25,"timestamp":1786443000000,"latitude":39.94,"longitude":-79.26},{"id":"iem_F_39.940_-79.260_1786437060000","source":"iem","severity":"low","severityValue":25,"timestamp":1786437060000,"latitude":39.94,"longitude":-79.26},{"id":"iem_F_40.100_-78.840_1786442700000","source":"iem","severity":"low","severityValue":25,"timestamp":1786442700000,"latitude":40.1,"longitude":-78.84},{"id":"iem_D_39.770_-79.200_1786425300000","source":"iem","severity":"low","severityValue":25,"timestamp":1786425300000,"latitude":39.77,"longitude":-79.2},{"id":"iem_F_39.900_-79.160_1786441500000","source":"iem","severity":"low","severityValue":25,"timestamp":1786441500000,"latitude":39.9,"longitude":-79.16}] |
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 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 34/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.