Right now
The most recent data we hold from NOAA arrived 5 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
5 other detections within 20 km in the last 24 hours, the nearest <1 km from here.
This alert expired on 19 September 2026 at 03:45 UTC. It is kept here as a record.
No stronger detection stands among the 9 recorded within 20 km of this point since 11 April 2026 — 2 others scored the same. The last comparable one was on 18 September 2026. 5 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued September 18 at 7:32PM MDT until September 18 at 9:45PM MDT by NWS Grand Junction CO
Nearby, since 11 April 2026
- September 19, 2026 · score 28 · 19.3 km
How we know
3 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 | High |
| Calamity Score (ours) | 28 / 100 |
| Legacy data-support index | 0.71/1 |
| Coordinates | 40.1464, -109.2464 |
| Nearest City | Grand Junction (135 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-09-19T01:32:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.8336263cfca35cb3339eb471d6361b2c305d3282.001.1 |
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: 2026-09-19T01:32:00.000Z.
First archived: 2026-09-19T01:35:31.258Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-19T03:43:47.123Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:38:28.417Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:33:09.232Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:27:50.153Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:22:31.774Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:17:13.331Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:11:52.529Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T03:01:09.820Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:55:49.736Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:50:29.372Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:45:08.813Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:39:49.601Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:29:12.272Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:23:53.522Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:18:34.713Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:13:11.789Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:07:48.195Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T02:02:27.826Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T01:57:07.587Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
2026-09-19T01:51:44.957Z · data_change
Index 28 → 28; severity high → high; version 5 → 5.
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Moffat, CO; Rio Blanco, CO; Uintah, UT |
| Headline | Flash Flood Warning issued September 18 at 7:32PM MDT until September 18 at 9:45PM MDT by NWS Grand Junction CO |
| Expires | 2026-09-18T21:45:00-06:00 |
| SenderName | NWS Grand Junction CO |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 100 |
| Spc Location | 6 NNW Massadona |
| Spc County | Moffat |
| Spc State | CO |
| Spc Comments | Maximum hail size 1.00 inch... average hail size 0.50 inch. (GJT) |
| Iem TypeSummary | R |
| Iem Magnitude | 0.81 |
| Iem Unit | Inch |
| Iem City | Dinosaur |
| Iem County | Moffat |
| Iem State | CO |
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.
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