Right now
The most recent data we hold from NOAA arrived 20 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 5 July 2026 at 00:01 UTC. It is kept here as a record.
It is the 76th strongest of the 287 detections recorded within 20 km of this point since 17 March 2026. Another comparable one was recorded here earlier the same day. 16 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 4 at 7:51PM EDT until July 4 at 8:00PM EDT by NWS Mount Holly NJ
Urban PEI: 673,898 within a heuristic 50 km radius; not unique people.
Nearby, since 17 March 2026
- August 3, 2026 · score 54 · 5.1 km
- September 2, 2026 · score 46 · 8.4 km
- August 2, 2026 · score 37 · 8.9 km
How we know
8 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 48 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) | 48 / 100 |
| Legacy data-support index | 0.89/1 |
| Coordinates | 38.8327, -76.3412 |
| Nearest City | Annapolis (21 km) |
| Urban exposure index (PEI) | 673.9K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-04T23:51:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.b76a2f1c6847ad94572d95fc3e2f284f |
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: 2026-07-04T23:51:00.000Z.
First archived: 2026-07-04T23:57:21.545Z. 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 | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Delaware Bay waters north of East Point NJ to Slaughter Beach DE; Delaware Bay waters south of East Point NJ to Slaughter Beach DE; Coastal waters from Cape May NJ to Cape Henlopen DE out 20 NM; Chesapeake Bay north of Pooles Island MD; Tidal Potomac from Key Bridge to Indian Head MD; Tidal Potomac from Indian Head to Cobb Island MD and 3 more areas |
| Headline | Special Marine Warning issued July 4 at 7:51PM EDT until July 4 at 8:00PM EDT by NWS Mount Holly NJ |
| Expires | 2026-07-04T20:01:00-04:00 |
| SenderName | NWS Mount Holly NJ |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.b76a2f1c6847ad94572d95fc3e2f284fd4235642.001.1","noaa_urn:oid:2.49.0.1.840.0.32c557827a7821bff9512afc227ea0493502e958.001.1","noaa_urn:oid:2.49.0.1.840.0.94cd82fd3313d641826dd02d388a108cd3618a62.001.1","noaa_urn:oid:2.49.0.1.840.0.ad5d69b42c7061da938b6aab421b08a5dab85e1e.001.1","noaa_urn:oid:2.49.0.1.840.0.065947f712cae25f598eeab37f26c1f62255aad4.001.1","noaa_urn:oid:2.49.0.1.840.0.331f3a4b944f799598eaadf2f6a479815eaeb569.002.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | mph |
| Iem City | BWI Marshall Airport |
| Iem County | Anne Arundel |
| Iem State | MD |
| Iem Wfo | LWX |
| Iem Remark | A wind gust of 50 knots (58 MPH) was measured by the ASOS at Baltimore-Washington Thurgood Marshall International Airport (KBWI). |
| MergedSources | [{"id":"iem_D_38.520_-76.590_1783206780000","source":"iem","severity":"low","severityValue":25,"timestamp":1783206780000,"latitude":38.52,"longitude":-76.59},{"id":"iem_M_38.850_-77.030_1783204320000","source":"iem","severity":"low","severityValue":25,"timestamp":1783204320000,"latitude":38.85,"longitude":-77.03},{"id":"iem_D_39.110_-76.610_1783206900000","source":"iem","severity":"low","severityValue":25,"timestamp":1783206900000,"latitude":39.11,"longitude":-76.61},{"id":"iem_H_39.150_-76.630_1783206000000","source":"iem","severity":"low","severityValue":25,"timestamp":1783206000000,"latitude":39.15,"longitude":-76.63},{"id":"iem_D_38.550_-76.590_1783206900000","source":"iem","severity":"low","severityValue":25,"timestamp":1783206900000,"latitude":38.55,"longitude":-76.59},{"id":"iem_M_38.870_-77.020_1783204560000","source":"iem","severity":"low","severityValue":25,"timestamp":1783204560000,"latitude":38.87,"longitude":-77.02},{"id":"iem_G_39.170_-76.680_1783206540000","source":"iem","severity":"low","severityValue":25,"timestamp":1783206540000,"latitude":39.17,"longitude":-76.68}] |
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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