Right now
The most recent data we hold from NOAA arrived 5 minutes ago, and this point is in it.
Nothing else has been detected within 20 km in the last 24 hours.
This alert is in force until 18 September 2026, 04:15 UTC.
It is the 64th strongest of the 212 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 12 September 2026. 79 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued September 17 at 9:16PM EDT until September 18 at 12:15AM EDT by NWS State College PA
Urban PEI: 19,966 within a heuristic 50 km radius; not unique people.
Nearby, since 17 March 2026
- July 18, 2026 · score 58 · 1.4 km
- June 6, 2026 · score 39 · 11.5 km
- July 7, 2026 · score 34 · 12.1 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 28 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v5. 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 |
| Legacy data-support index | 0.86/1 |
| Coordinates | 40.2108, -78.9692 |
| Nearest City | Johnstown (14 km) |
| Urban exposure index (PEI) | 20.0K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-18T01:16:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.082954106522aad75e7c26c8ba00c70c57d2dd5e.001.1 |
Physical priority index · v5. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-09-18T01:16:00.000Z.
First archived: 2026-09-18T01:23:09.484Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-18T03:03:53.816Z · data_change
Index 28 → 28; severity medium → medium; version 5 → 5.
2026-09-18T02:32:14.817Z · data_change
Index 28 → 28; severity medium → medium; version 5 → 5.
2026-09-18T02:00:34.961Z · data_change
Index 28 → 28; severity medium → medium; version 5 → 5.
2026-09-18T01:39:23.581Z · data_change
Index 28 → 28; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Somerset, PA |
| Headline | Flash Flood Warning issued September 17 at 9:16PM EDT until September 18 at 12:15AM EDT by NWS State College PA |
| Expires | 2026-09-18T00:15:00-04:00 |
| SenderName | NWS State College PA |
| HasExactCoords | true |
| Iem TypeSummary | F |
| Iem City | 1 S Davidsville |
| Iem County | Somerset |
| Iem State | PA |
| Iem Wfo | CTP |
| Iem Remark | Flooded basement on South Main Street in Davidsville. Report of 18 inches of water in the basement. |
| MergedSources | [{"id":"iem_F_40.210_-79.040_1789695900000","source":"iem","severity":"low","severityValue":25,"timestamp":1789695900000,"latitude":40.21,"longitude":-79.04},{"id":"iem_F_40.220_-78.940_1789694400000","source":"iem","severity":"low","severityValue":25,"timestamp":1789694400000,"latitude":40.22,"longitude":-78.94}] |
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.
Review the area, threshold and delivery channel in your account.
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