Right now
The most recent data we hold from NOAA arrived 24 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 21 March 2026 at 06:00 UTC. It is kept here as a record.
No stronger detection stands among the 36 recorded within 20 km of this point since 18 March 2026 — 35 others scored the same. The last comparable one was on 20 March 2026. 25 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flood Warning issued March 20 at 2:35PM PDT until March 21 at 3:15PM PDT by NWS Seattle WA
Urban PEI: 1,146,604 within a heuristic 50 km radius; not unique people.
Nearby, since 18 March 2026
- March 21, 2026 · score 52 · 0.0 km
- March 21, 2026 · score 52 · 9.4 km
- March 20, 2026 · score 52 · 22.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 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) | 52 / 100 |
| Legacy data-support index | 0.81/1 |
| Coordinates | 47.9870, -121.9595 |
| Nearest City | Lake Stevens (8 km) |
| Urban exposure index (PEI) | 1.1M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-03-21T06:00:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flood Warning_noaa_urn:oid:2.49.0.1.840.0.90e27ddc7cf5e961243c4d1de1b82162 |
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: 2026-03-21T06:00:00.000Z.
First archived: 2026-03-20T21:59:00.674Z. 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 | Snohomish, WA; Whatcom, WA; King, WA and 4 more areas |
| Headline | Flood Warning issued March 20 at 2:35PM PDT until March 21 at 3:15PM PDT by NWS Seattle WA |
| Expires | 2026-03-20T23:00:00-07:00 |
| SenderName | NWS Seattle WA |
| HasExactCoords | true |
| MergedCount | 16 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.90e27ddc7cf5e961243c4d1de1b82162b013fbaf.001.1","noaa_urn:oid:2.49.0.1.840.0.ac97df6a85c51b6d8a755fa7c0fff808619636ba.001.1","noaa_urn:oid:2.49.0.1.840.0.a23cc22b1001db4129f40a61bd02e6cb39e52e29.001.1","noaa_urn:oid:2.49.0.1.840.0.d853be6a25fae905953bb357397170de51947958.001.1","noaa_urn:oid:2.49.0.1.840.0.717a7ad0e65ab65e425a2f9fa099f4cc1821e675.001.1","noaa_urn:oid:2.49.0.1.840.0.e5e3f1075d1da5bfbd914b9e7e90135241ff701c.001.1","noaa_urn:oid:2.49.0.1.840.0.253230f13cfabec2c4ca987e4c7babd0f5093d56.001.1","noaa_urn:oid:2.49.0.1.840.0.6f0fe0b980b90f80c22d9039bb104c7ba5416312.001.1","noaa_urn:oid:2.49.0.1.840.0.bb756ebb6ce349f0d0119feb0d2618b0ec9141b9.001.1","noaa_urn:oid:2.49.0.1.840.0.88fce17f62eab6f344da5a2d0e6e02899091345f.001.1","noaa_urn:oid:2.49.0.1.840.0.cf1a116a7032f5702b24e3228eb8545fa5669e00.001.1","noaa_urn:oid:2.49.0.1.840.0.52c13597362e3eee822d9029cb46fa080787b619.001.1","noaa_urn:oid:2.49.0.1.840.0.af143bcc4bb3a9c53aa7c4dd660c9f3bb0f592e4.001.1","noaa_urn:oid:2.49.0.1.840.0.5c4a238819439134240b39eea1383cc190fe9482.001.1","noaa_urn:oid:2.49.0.1.840.0.1494865752fe4badd66e4cd085efd94b05ad3e67.001.1","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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