This alert expired on 7 July 2026 at 03:30 UTC. It is kept here as a record.
It is the 3rd strongest of the 128 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 6 July 2026. 17 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Flash Flood Warning issued July 6 at 8:21PM EDT until July 6 at 11:30PM EDT by NWS Baltimore MD/Washington DC
An estimated 2,155,419 people live within 50 km of this point.
Nearby, since 16 March 2026
- July 6, 2026 · score 52 · 3.7 km
- August 10, 2026 · score 52 · 4.2 km
- March 16, 2026 · score 52 · 5.8 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 91 % 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) | 52 / 100 |
| Our confidence | 91% |
| Coordinates | 39.4204, -76.3955 |
| Nearest City | Perry Hall (6 km) |
| Population Exposed | 2.2M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-07T00:21:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.7cb8461c06cb4289194ca0db5fb8fa27 |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Harford, MD; Baltimore, MD; Baltimore City, MD |
| Headline | Flash Flood Warning issued July 6 at 8:21PM EDT until July 6 at 11:30PM EDT by NWS Baltimore MD/Washington DC |
| Expires | 2026-07-06T23:30:00-04:00 |
| SenderName | NWS Baltimore MD/Washington DC |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.7cb8461c06cb4289194ca0db5fb8fa27a4e66e50.001.1","noaa_urn:oid:2.49.0.1.840.0.330dfb80877333ca59be129076a7bee68b93cc70.001.1","noaa_urn:oid:2.49.0.1.840.0.a5265d65cdb8fb9e9797ce598ca97bf263ce995b.001.1"] |
| Iem TypeSummary | R |
| Iem Magnitude | 3.36 |
| Iem Unit | Inch |
| Iem City | 1 S Centreville |
| Iem County | Queen Annes |
| Iem State | MD |
| Iem Wfo | PHI |
| Iem Remark | Mesonet station FW8736 Centreville. |
| MergedSources | [{"id":"iem_R_39.030_-75.890_1783372500000","source":"iem","severity":"low","severityValue":25,"timestamp":1783372500000,"latitude":39.03,"longitude":-75.89},{"id":"iem_R_39.020_-76.070_1783372800000","source":"iem","severity":"low","severityValue":25,"timestamp":1783372800000,"latitude":39.02,"longitude":-76.07}] |
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 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 52/100, near Perry Hall (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.