Right now
The most recent data we hold from NOAA arrived 13 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 5 km from here.
This alert expired on 16 September 2026 at 20:45 UTC. It is kept here as a record.
No stronger detection stands among the 14 recorded within 20 km of this point since 30 March 2026 — 4 others scored the same. Another comparable one was recorded here earlier the same day. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued September 16 at 11:51AM MST until September 16 at 1:45PM MST by NWS Phoenix AZ
Urban PEI: 1,700,093 within a heuristic 50 km radius; not unique people.
Nearby, since 30 March 2026
- September 16, 2026 · score 41 · 15.0 km
- September 16, 2026 · score 46 · 15.2 km
- September 17, 2026 · score 46 · 15.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 46 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) | 46 / 100 |
| Legacy data-support index | 0.82/1 |
| Coordinates | 33.1016, -111.6631 |
| Nearest City | San Tan Valley (16 km) |
| Urban exposure index (PEI) | 1.7M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-16T18:51:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.27dcc368c2044b78f68e2d32a980de4ff081f056.001.1 |
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: 2026-09-16T18:51:00.000Z.
First archived: 2026-09-16T18:56:44.405Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Maricopa, AZ; Maricopa, AZ; Pinal, AZ; Pima, AZ and 2 more areas |
| Headline | Flash Flood Warning issued September 16 at 11:51AM MST until September 16 at 1:45PM MST by NWS Phoenix AZ |
| Expires | 2026-09-16T13:45:00-07:00 |
| SenderName | NWS Phoenix AZ |
| HasExactCoords | true |
| MergedCount | 7 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.27dcc368c2044b78f68e2d32a980de4ff081f056.001.1","noaa_urn:oid:2.49.0.1.840.0.c53d4a567da793fd93593340370bc1f8abc8c97e.001.1","noaa_urn:oid:2.49.0.1.840.0.6e508992035c65227d7b81ad57f3e3d2fe42c734.001.1","noaa_urn:oid:2.49.0.1.840.0.40f47c64079415325f8ad6bb4bb0c9ecaa8355fc.001.1","noaa_urn:oid:2.49.0.1.840.0.4a462d8f945534852296a085e81d8cd928423b55.001.1","noaa_urn:oid:2.49.0.1.840.0.f25d086eabb4bbf2db069240fe26dd81325f55d2.001.1","noaa_urn:oid:2.49.0.1.840.0.2406976b68f8b27ed73142cc200871e0eef0f4c8.001.1"] |
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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