Right now
The most recent data we hold from NOAA arrived 10 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
This alert expired on 20 March 2026 at 17:15 UTC. It is kept here as a record.
What the source measured
NOAA reported: Flood Warning issued March 20 at 2:09AM PDT until March 21 at 7:35AM PDT by NWS Seattle WA
Urban PEI: 897,984 within a heuristic 50 km radius; not unique people.
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 48 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 v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 48 / 100 |
| Legacy data-support index | 0.81/1 |
| Coordinates | 47.7938, -121.6104 |
| Nearest City | Monroe (28 km) |
| Urban exposure index (PEI) | 898.0K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-20T13:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flood Warning_noaa_urn:oid:2.49.0.1.840.0.b362aebc27483e1623115fc365c23f23 |
Physical priority index · v1. 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: 2026-03-20T13:51:00.000Z.
First archived: 2026-03-20T09:32:41.515Z. 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 | Flood Warning |
| Urgency | Expected |
| Certainty | Likely |
| AreaDesc | King, WA; Snohomish, WA; Chelan, WA and 2 more areas |
| Headline | Flood Warning issued March 20 at 2:09AM PDT until March 21 at 7:35AM PDT by NWS Seattle WA |
| Expires | 2026-03-20T10:15:00-07:00 |
| SenderName | NWS Seattle WA |
| HasExactCoords | true |
| MergedCount | 8 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b362aebc27483e1623115fc365c23f233d4b23e9.001.1","noaa_urn:oid:2.49.0.1.840.0.317aa51423d66bbb25d2235c1465d324a1730100.001.1","noaa_urn:oid:2.49.0.1.840.0.052a58dbe5555f3c933a429ba58eb331a93e01e9.001.1","noaa_urn:oid:2.49.0.1.840.0.8abf53af62109d1cfdb93bcdc350d12ca1064b7c.001.1","noaa_urn:oid:2.49.0.1.840.0.1315d300d27dfa261bca05704b56535b20596bfd.001.1","noaa_urn:oid:2.49.0.1.840.0.34fa714d91013805c5f775cdcb499ef26261a648.001.1","noaa_urn:oid:2.49.0.1.840.0.34fa714d91013805c5f775cdcb499ef26261a648.002.1","noaa_urn:oid:2.49.0.1.840.0.099ca6dc3e7338ac94524aa7e4e2660eb8929cfa.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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