Right now
The most recent data we hold from NOAA arrived 15 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 27 May 2026 at 18:03 UTC. It is kept here as a record.
It is the 2nd strongest of the 21 detections recorded within 20 km of this point since 26 April 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: Flash Flood Warning issued May 27 at 12:53PM CDT until May 27 at 1:00PM CDT by NWS Fort Worth TX
An estimated 568,455 people live within 50 km of this point.
Nearby, since 26 April 2026
- June 12, 2026 · score 43 · 6.3 km
- May 27, 2026 · score 48 · 18.5 km
- May 10, 2026 · score 43 · 18.9 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 48 out of 100, at 90 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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 |
| Our confidence | 90% |
| Coordinates | 33.4574, -96.4579 |
| Nearest City | Sherman (25 km) |
| Population Exposed | 568.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-27T17:53:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Flash Flood Warning_noaa_urn:oid:2.49.0.1.840.0.cdbbf3b1f8e5cdaad3ed603082c41f5f |
Score Breakdown
Technical Details
| Event | Flash Flood Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Collin, TX; Fannin, TX; Grayson, TX |
| Headline | Flash Flood Warning issued May 27 at 12:53PM CDT until May 27 at 1:00PM CDT by NWS Fort Worth TX |
| Expires | 2026-05-27T13:03:00-05:00 |
| SenderName | NWS Fort Worth TX |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.cdbbf3b1f8e5cdaad3ed603082c41f5fd1bad64c.001.1","noaa_urn:oid:2.49.0.1.840.0.a1096d26f0c775067c1a15cdabc50df7a1714bdb.001.1"] |
| Iem TypeSummary | F |
| Iem City | 1 E Sachse |
| Iem County | Dallas |
| Iem State | TX |
| Iem Wfo | FWD |
| Iem Remark | Emergency Manager reported road closure of Sachse Rd at Country Club Rd due to high water. |
| MergedSources | [{"id":"iem_F_33.380_-96.350_1779898500000","source":"iem","severity":"low","severityValue":25,"timestamp":1779898500000,"latitude":33.38,"longitude":-96.35},{"id":"iem_F_32.820_-96.470_1779897600000","source":"iem","severity":"low","severityValue":25,"timestamp":1779897600000,"latitude":32.82,"longitude":-96.47},{"id":"iem_F_32.980_-96.560_1779900480000","source":"iem","severity":"low","severityValue":25,"timestamp":1779900480000,"latitude":32.98,"longitude":-96.56}] |
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 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.
Want to know when something happens near Sherman?
Calamity.live data shows a weather event with CalamityScore 48/100, near Sherman (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.