Right now
The most recent data we hold from NOAA arrived 21 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 4 July 2026 at 23:15 UTC. It is kept here as a record.
No stronger detection stands among the 128 recorded within 20 km of this point since 16 March 2026 — 47 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: Severe Thunderstorm Warning issued July 4 at 6:52PM EDT until July 4 at 7:15PM EDT by NWS Baltimore MD/Washington DC
Urban PEI: 194,544 within a heuristic 50 km radius; not unique people.
Nearby, since 16 March 2026
- August 7, 2026 · score 37 · 1.6 km
- July 4, 2026 · score 43 · 9.7 km
- July 10, 2026 · score 43 · 9.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
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 | 0.78/1 |
| Coordinates | 40.0513, -76.5410 |
| Nearest City | York (19 km) |
| Urban exposure index (PEI) | 194.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T22:52:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.6e8fc0f754c61c136b22b8173a678be7 |
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: 2026-07-04T22:52:00.000Z.
First archived: 2026-07-04T22:55:09.376Z. 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 | Anne Arundel, MD; Howard, MD; Prince Georges, MD; Culpeper, VA; Fairfax, VA; Fauquier, VA; Loudoun, VA; Prince William, VA; Rappahannock, VA; Cumberland, PA; Dauphin, PA; Lebanon, PA; Perry, PA; York, PA and 22 more areas |
| Headline | Severe Thunderstorm Warning issued July 4 at 6:52PM EDT until July 4 at 7:15PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-07-04T19:15:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 25 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.6e8fc0f754c61c136b22b8173a678be74ca6a1e9.001.1","noaa_urn:oid:2.49.0.1.840.0.79289cc46fc29e0a354e57d144c919c2dacdc8b9.001.1","noaa_urn:oid:2.49.0.1.840.0.1aee4af03e096062062474ec569ee8fc1c8819e7.002.1","noaa_urn:oid:2.49.0.1.840.0.387cec28806225e508b302c302aea1ae5bb715fa.001.1","noaa_urn:oid:2.49.0.1.840.0.d46ab000e827c8b3518eb05b98a7e14ae69ec134.001.1","noaa_urn:oid:2.49.0.1.840.0.8fddeb9116067e650553fde6c70ee084f54605de.001.1","noaa_urn:oid:2.49.0.1.840.0.0122134260b6b06ebfd8e0717b92fed562930178.002.1","noaa_urn:oid:2.49.0.1.840.0.8196109d015fda27bc14a9c5cf9dc147f634d6be.002.1","noaa_urn:oid:2.49.0.1.840.0.b28ac9b9f0a4582370efec53a09bf74ca6e02ed5.001.1","noaa_urn:oid:2.49.0.1.840.0.c97ce057487cd3978dd328049df138475344a24c.001.1","noaa_urn:oid:2.49.0.1.840.0.287fec160dfbb6dc1ff0b893ae38e9154c67b5b9.002.1","noaa_urn:oid:2.49.0.1.840.0.0c7e954421f27d0f9d1c623877f99ed8ca3244df.001.1","noaa_urn:oid:2.49.0.1.840.0.ac1e2141d184c3c1d1bc9179b55c0ae8866c5045.001.1","noaa_urn:oid:2.49.0.1.840.0.f45f276329f77333a63db1cba37bfea8f30cb702.001.1","noaa_urn:oid:2.49.0.1.840.0.737bb966f57c8144bd10cbc6cf9dd26128f63bec.001.1","noaa_urn:oid:2.49.0.1.840.0.54be9178ee66d52b2cedda8c70f7c1dc12ff5cd4.001.1","noaa_urn:oid:2.49.0.1.840.0.691c23b708b67fed027bdfc9b4f7b7824b15f7aa.001.1","noaa_urn:oid:2.49.0.1.840.0.f38f8e312727aadc9fc8e6c95247319757addcf7.001.1","noaa_urn:oid:2.49.0.1.840.0.dc0306bec74bf63dffad1f27ddbcb7edc6055824.001.1","noaa_urn:oid:2.49.0.1.840.0.6e10c851f5e554888bc57f4255b96992d1919a38.001.1","noaa_urn:oid:2.49.0.1.840.0.bc56a8eb233ccb3f04776b68c79cee592ac04783.001.1","noaa_urn:oid:2.49.0.1.840.0.a87ddab614371e8e0cb6291c62ab53cfb2245cba.001.1","noaa_urn:oid:2.49.0.1.840.0.53e65627ae00e3ff7586c9b85e92c5b1ac701f07.001.1","noaa_urn:oid:2.49.0.1.840.0.ec681db4cdeecc21f249f4c14d14bc514f62674e.001.1","noaa_urn:oid:2.49.0.1.840.0.3462a58b6a7855c172ef2c1007072a90039d9f41.001.1"] |
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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