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 4 August 2026 at 21:00 UTC. It is kept here as a record.
What the source measured
NOAA reported: Flash Flood Warning issued August 4 at 2:34PM EDT until August 4 at 5:00PM EDT by NWS Wakefield VA
Urban PEI: 273,974 within a heuristic 50 km radius; not unique people.
How we know
6 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 43 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) | 43 / 100 |
| Legacy data-support index | 0.91/1 |
| Coordinates | 37.1241, -76.9421 |
| Nearest City | Williamsburg (26 km) |
| Urban exposure index (PEI) | 274.0K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-04T18:34:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.edb35b65804f28318059e722150e144d |
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: 2026-08-04T18:34:00.000Z.
First archived: 2026-08-04T18:49:18.743Z. 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 | Isle of Wight, VA; City of Suffolk, VA; Chesterfield, VA; City of Richmond, VA; Chesterfield, VA; Prince George, VA; City of Colonial Heights, VA; City of Hopewell, VA and 1 more areas |
| Headline | Flash Flood Warning issued August 4 at 2:34PM EDT until August 4 at 5:00PM EDT by NWS Wakefield VA |
| Expires | 2026-08-04T17:00:00-04:00 |
| SenderName | NWS Wakefield VA |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.edb35b65804f28318059e722150e144dc8c1a184.001.1","noaa_urn:oid:2.49.0.1.840.0.86aea473ecaf0bc57910e2982892fd3dc047bb4b.001.1","noaa_urn:oid:2.49.0.1.840.0.7e286ff3ab82dfbdc1621909e986a8ad5b522e10.001.1","noaa_urn:oid:2.49.0.1.840.0.11cc39fd6a736f96fd8cb2978794fdf40a1af597.001.1"] |
| Iem TypeSummary | F |
| Iem City | Downtown Portsmout |
| Iem County | City of Portsmouth |
| Iem State | VA |
| Iem Wfo | AKQ |
| Iem Remark | Flooding being reported along portions of Effingham St from 264 to Crawford Pkwy. |
| MergedSources | [{"id":"iem_F_36.860_-76.290_1785865500000","source":"iem","severity":"low","severityValue":25,"timestamp":1785865500000,"latitude":36.86,"longitude":-76.29},{"id":"iem_F_37.370_-77.330_1785868440000","source":"iem","severity":"low","severityValue":25,"timestamp":1785868440000,"latitude":37.37,"longitude":-77.33},{"id":"iem_F_36.850_-76.290_1785865980000","source":"iem","severity":"low","severityValue":25,"timestamp":1785865980000,"latitude":36.85,"longitude":-76.29},{"id":"iem_F_37.300_-77.300_1785867960000","source":"iem","severity":"low","severityValue":25,"timestamp":1785867960000,"latitude":37.3,"longitude":-77.3},{"id":"iem_F_36.830_-76.310_1785867300000","source":"iem","severity":"low","severityValue":25,"timestamp":1785867300000,"latitude":36.83,"longitude":-76.31}] |
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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