What happened
AI-written · may contain mistakes. Written from the advisory text and weather only.
Cause: Too many flights were bunched together at Seattle-Tacoma for the airport to handle at once, so departures from three air traffic control centers were held.
A ground stop at Seattle-Tacoma began at 16:18 UTC on November 12, 2026, and ended at 17:10 UTC after 52 minutes. The advisory listed 283 total delays, with a maximum of 72 and an average of 31. It was not extended, and the stop was lifted before its scheduled end time.
Impact by airline
Aircraft seen on the ground at SEA and holding nearby, by airline.
| Airline | On ground | Holding |
|---|---|---|
| Alaska Airlines AS | 20 | — |
| Delta Air Lines DL | 11 | — |
| SkyWest Airlines OO | 6 | — |
| Horizon Air QX | 4 | — |
| American Airlines AA | 1 | — |
| ABX Air GB | 1 | — |
| Empire Airlines PN | 1 | — |
| Cargolux CV | 1 | — |
| Southwest Airlines WN | 1 | — |
| United Airlines UA | 1 | — |
Impact by region
Air traffic control centers whose departures to the airport were held.
| Center | Status |
|---|---|
| Salt Lake City Center (ZLC) | Held |
| Oakland Center (ZOA) | Held |
| Seattle Center (ZSE) | Held |
Aircraft at the airport
Peak 38 on the ground, 0 holding nearby.
On the ground Holding nearby
Timeline
Every change published while the ground stop was in effect, as seen each minute.
Ground stop issued at SEA for airport volume, until 9:30 am PST. Departures held from ZLC, ZOA, ZSE.
Ground stop ended after 52 min.
Advisories
The air traffic control advisories issued for this ground stop, as published.
ATCSCC ADVZY 047 SEA/ZSE 11/12/2026 CDM GROUND STOP
CTL ELEMENT: SEA ELEMENT TYPE: APT ADL TIME: 1616Z GROUND STOP PERIOD: 12/1601Z - 12/1730Z DEP FACILITIES INCLUDED: (Manual) ZLC ZOA ZSE PREVIOUS TOTAL, MAXIMUM, AVERAGE DELAYS: 0 / 0 / 0 NEW TOTAL, MAXIMUM, AVERAGE DELAYS: 283 / 72 / 31 PROBABILITY OF EXTENSION: LOW IMPACTING CONDITION: VOLUME / COMPACTED DEMAND COMMENTS:Original advisory ↗