This alert expired on 4 July 2026 at 22:45 UTC. It is kept here as a record.
No stronger detection stands among the 94 recorded within 20 km of this point since 17 March 2026 — 57 others scored the same. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 4 at 6:12PM EDT until July 4 at 6:45PM EDT by NWS Baltimore MD/Washington DC
An estimated 166,576 people live within 50 km of this point.
Nearby, since 17 March 2026
- May 20, 2026 · score 43 · 3.4 km
- May 20, 2026 · score 43 · 3.8 km
- August 10, 2026 · score 43 · 6.4 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 88 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 43 / 100 |
| Our confidence | 88% |
| Coordinates | 39.7944, -77.5737 |
| Nearest City | Chambersburg (18 km) |
| Population Exposed | 166.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T22:12:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.64cb25bcd0223e056c32b753608ce73c |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Carroll, MD; Frederick, MD; Adams, PA; Cumberland, PA; Juniata, PA; Perry, PA; Blair, PA; Cambria, PA; Centre, PA; Clearfield, PA; Huntingdon, PA and 20 more areas |
| Headline | Severe Thunderstorm Warning issued July 4 at 6:12PM EDT until July 4 at 6:45PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-07-04T18:45:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 24 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.64cb25bcd0223e056c32b753608ce73c2b416e8f.001.1","noaa_urn:oid:2.49.0.1.840.0.54f0b2f98f38b7ba520fbb33c4b8ba9119218ed6.001.1","noaa_urn:oid:2.49.0.1.840.0.0b0cca37919c85c1b0033505140e2fa1a0f34d64.001.1","noaa_urn:oid:2.49.0.1.840.0.b7f1edcc6d70841db5c917d5f67bacc110425a2f.002.1","noaa_urn:oid:2.49.0.1.840.0.b70303875f577a9d516b467dad91ef75a6306fc2.001.1","noaa_urn:oid:2.49.0.1.840.0.58fb3fe3b612ff17d409b19e36946055fbb1a763.001.1","noaa_urn:oid:2.49.0.1.840.0.be220bad9f5d69dfffc3db80d26235e68f8aa7f7.001.1","noaa_urn:oid:2.49.0.1.840.0.022e1c83061e407f5049fb1240cb0525b052f530.002.1","noaa_urn:oid:2.49.0.1.840.0.69c9facc3e20987abe2d389150fd6bb4d81b8f17.002.1","noaa_urn:oid:2.49.0.1.840.0.1ec97c4a3818e70cce88e9eb5c2a69e4bb7bb862.002.1","noaa_urn:oid:2.49.0.1.840.0.76087e31bb78c1a5eb645f879868a878c9a4dbf5.001.1","noaa_urn:oid:2.49.0.1.840.0.eedbbbcb12f87ee18ac842eb828bdc72b63a9331.001.1","noaa_urn:oid:2.49.0.1.840.0.8c23397594e33afa1b814c92678121638f84603f.001.1","noaa_urn:oid:2.49.0.1.840.0.5773bf30a487cfcf35a96548e6343f5a7f547d77.001.1","noaa_urn:oid:2.49.0.1.840.0.d9a496ee0cc15e093751d3815c2a1d604c75939c.001.1","noaa_urn:oid:2.49.0.1.840.0.1fde092403c28f887d08e36ac42a7cc31b47ec8c.001.1","noaa_urn:oid:2.49.0.1.840.0.5e4c66af247bd98fe1f17e932a39cb6ab3485f8d.001.1","noaa_urn:oid:2.49.0.1.840.0.4275c68d436cd07c039976d8e652fb2d493ac7b5.002.1","noaa_urn:oid:2.49.0.1.840.0.e6a11b829cf85a07bf87545083ff5d04a1787439.001.1","noaa_urn:oid:2.49.0.1.840.0.36339053bef2b81b3005864276c0667df9415221.001.1","noaa_urn:oid:2.49.0.1.840.0.61b0abade3b68b2792d32d24ba04427110d3889d.001.1","noaa_urn:oid:2.49.0.1.840.0.f0af0234e98e5d8f9dec99c40fc04cd56d0c127b.001.1","noaa_urn:oid:2.49.0.1.840.0.30817e062faa7d53f52015dda5d2fc784407e304.001.1","noaa_urn:oid:2.49.0.1.840.0.0556cf4e7f254c592436e2a310292d342aaf555b.001.1"] |
| Iem TypeSummary | D |
| Iem City | 3 SW Mcconnellsburg |
| Iem County | Fulton |
| Iem State | PA |
| Iem Wfo | CTP |
| Iem Remark | Trees down blocking Long View Road. |
| MergedSources | [{"id":"iem_D_39.820_-78.430_1783197000000","source":"iem","severity":"low","severityValue":25,"timestamp":1783197000000,"latitude":39.82,"longitude":-78.43},{"id":"iem_D_39.290_-77.860_1783201200000","source":"iem","severity":"low","severityValue":25,"timestamp":1783201200000,"latitude":39.29,"longitude":-77.86},{"id":"iem_D_40.040_-77.610_1783201800000","source":"iem","severity":"low","severityValue":25,"timestamp":1783201800000,"latitude":40.04,"longitude":-77.61},{"id":"iem_D_39.890_-78.030_1783199820000","source":"iem","severity":"low","severityValue":25,"timestamp":1783199820000,"latitude":39.89,"longitude":-78.03}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 43/100, near Chambersburg (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.