This alert is in force until 2 September 2026, 23:30 UTC.
It is the 25th strongest of the 43 detections recorded within 20 km of this point since 14 June 2026. The last comparable one was on 31 August 2026.
What the source measured
NOAA reported: Flash Flood Warning issued September 2 at 1:28PM MST until September 2 at 4:30PM MST by NWS Tucson AZ
An estimated 770,448 people live within 50 km of this point.
Nearby, since 14 June 2026
- July 12, 2026 · score 48 · 1.3 km
- August 10, 2026 · score 48 · 2.9 km
- August 29, 2026 · score 54 · 4.3 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 41 out of 100, at 81 % 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) | 41 / 100 |
| Our confidence | 81% |
| Coordinates | 31.8844, -111.0833 |
| Nearest City | Green Valley (10 km) |
| Population Exposed | 770.4K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T20:28:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.b8ee8ba494bc88754d6c7ca9a64f6dd8e12d1a48.001.1 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Pima, AZ |
| Headline | Flash Flood Warning issued September 2 at 1:28PM MST until September 2 at 4:30PM MST by NWS Tucson AZ |
| Expires | 2026-09-02T16:30:00-07:00 |
| SenderName | NWS Tucson AZ |
| HasExactCoords | true |
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 near Green Valley?
Calamity.live data shows a weather event with CalamityScore 41/100, near Green Valley (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.