Right now
The most recent data we hold from NOAA arrived 7 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 28 July 2026 at 22:00 UTC. It is kept here as a record.
It is the 5th strongest of the 180 detections recorded within 20 km of this point since 11 March 2026. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 28 at 5:02PM EDT until July 28 at 6:00PM EDT by NWS Baltimore MD/Washington DC
Urban PEI: 5,038,968 within a heuristic 50 km radius; not unique people.
Nearby, since 11 March 2026
- September 3, 2026 · score 46 · 7.1 km
- March 12, 2026 · score 52 · 8.3 km
- March 17, 2026 · score 52 · 9.5 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 | 0.80/1 |
| Coordinates | 39.2550, -77.0575 |
| Nearest City | Olney (12 km) |
| Urban exposure index (PEI) | 5.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-28T21:02:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.c42f5e8872785d124cb4e7cac386facc |
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: 2026-07-28T21:02:00.000Z.
First archived: 2026-07-28T21:05:08.318Z. 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 | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Culpeper, VA; Madison, VA; Page, VA; Rappahannock, VA; Calvert, MD; St. Marys, MD; Culpeper, VA; Fauquier, VA; Rappahannock, VA and 5 more areas |
| Headline | Severe Thunderstorm Warning issued July 28 at 5:02PM EDT until July 28 at 6:00PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-07-28T18:00:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 8 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.c42f5e8872785d124cb4e7cac386faccf74e130e.001.1","noaa_urn:oid:2.49.0.1.840.0.3e3b1816d596d4d164cda159f9027a6d82b51649.001.1","noaa_urn:oid:2.49.0.1.840.0.e0faed5bcb3340e5c1bb53a19fab5b543b2ee1ec.001.1","noaa_urn:oid:2.49.0.1.840.0.275d265dbce47c238ca216dd53a4850ca50c5713.002.1","noaa_urn:oid:2.49.0.1.840.0.a67f4d78ea21c5da9a3a3e8923087929dc89ac74.002.1","noaa_urn:oid:2.49.0.1.840.0.0decc6c10e1617c1e5bfc19f2a4a90674fbe4fe1.001.1","noaa_urn:oid:2.49.0.1.840.0.f3ca77ef539bcd23510193f263cb3234d1f89871.001.1","noaa_urn:oid:2.49.0.1.840.0.c2f8e77be74df8eb5b0838f4228696f6b311fc1d.002.1"] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
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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