KSEA Runway 16L/34R — Seattle–Tacoma International Airport

Nov 3, 2026 (airport-local day): 0 configuration changes since local midnight, from the tower's TFDM configuration ATIS Alerts recorded. A change is a different arrival or departure set; a new ATIS letter with the same runways is folded into the row it belongs to. The history section below counts the same way over rolling windows.

1. 08:05Z12:05 AM PST(in effect since before the day began)

   7.3 h · current
   Arrivals

   16C16R

   Departures

   16L
   South flowIn effect at the start of the day

Time · runway 16L/34R · airport-wide outlook · confidence · forecast wind · why

1. Now1520Z · 7:20 AM PST·16L/34R: 16L in use·Current airport configuration (tower TFDM): arrivals 16C · 16R · departures 16L·stated·wind 320° at 3 kt
2. +1 h1620Z · 8:20 AM PST·16L/34R: 34R likely·airport-wide likely 34R then 34C·North flow·5 kt headwind, 0 kt crosswind·Low 50%·wind 360° at 5 kt·Why TAF forecast wind 360° at 5 kt favors north-facing runway ends: 5 kt headwind and 0 kt crosswind on 34R versus 5 kt headwind on 34C.|This would be a change from the current 16C and 16R configuration.|Runway 16C is excluded: stated closed.|Confidence falls with forecast distance (+1 h).
3. +2 h1720Z · 9:20 AM PST·16L/34R: 34R likely·airport-wide likely 34R then 34C·North flow·5 kt headwind, 0 kt crosswind·Low 47%·wind 360° at 5 kt·Why TAF forecast wind 360° at 5 kt favors north-facing runway ends: 5 kt headwind and 0 kt crosswind on 34R versus 5 kt headwind on 34C.|This would be a change from the current 16C and 16R configuration.|Runway 16C is excluded: stated closed.|Confidence falls with forecast distance (+2 h).
4. +3 h1820Z · 10:20 AM PST·16L/34R: 34R likely·airport-wide likely 34R then 34C·North flow·5 kt headwind, 0 kt crosswind·Low 44%·wind 360° at 5 kt·Why TAF forecast wind 360° at 5 kt favors north-facing runway ends: 5 kt headwind and 0 kt crosswind on 34R versus 5 kt headwind on 34C.|This would be a change from the current 16C and 16R configuration.|Runway 16C is excluded: stated closed.|Confidence falls with forecast distance (+3 h).
5. +6 h2120Z · 1:20 PM PST·16L/34R: 34R likely·airport-wide likely 34R then 34C·North flow·5 kt headwind, 0 kt crosswind·Low 35%·wind 360° at 5 kt·Why TAF forecast wind 360° at 5 kt favors north-facing runway ends: 5 kt headwind and 0 kt crosswind on 34R versus 5 kt headwind on 34C.|This would be a change from the current 16C and 16R configuration.|Runway 16C is excluded: stated closed.|Confidence falls with forecast distance (+6 h).
6. +12 h0320Z · 7:20 PM PST·16L/34R: 34R likely·airport-wide likely 34R·North flow·Low 55%·wind 020° at 4 kt·Why TAF wind 020° at 4 kt: below 5 kt, wind does not decide the runway.|In recorded use, 34R is the end this airport most often named for arrivals in calm wind (tower TFDM).|That would be a change from the current 16C and 16R configuration.|Runway 16C is excluded: stated closed.

ATIS Alerts Predicted Runway is an estimate from the TAF wind forecast, runway geometry (most headwind, crosswind penalised, tailwind over 5 kt avoided, longest runway breaks ties), the current stated configuration and any stated closures; recorded tower use since Sep 18, 2026 (720 h) is an input wherever a wind sector has 24 h on record. Each row lists its reasons; “no runway favored” is a genuine answer under variable or light wind, never replaced by a guess. It is not an ATC assignment and does not know about noise abatement or traffic flow unless the recorded history shows them. TAF issued 1357Z (5:57 AM PST).

Source: FAA NASR 28-day subscription, cycle effective 2026-10-01 (equipment on record) · FAA NOTAMs via SWIM (live)and the current D-ATIS (outages). “Not available” means the FAA record lists no such equipment for the end; nothing here is inferred. An outage annotation is only ever a reading of the official text shown with it. Declared distances are not shown in this phase.

The current D-ATIS does not state LAHSO in effect. Source: FAA NASR cycle 2026-10-01; D-ATIS text read by ATIS Alerts.

Rows marked “Runway 16L/34R” are sectorized to this runway complex in the FAA record; “Airport-wide” rows serve every runway. Source: FAA NASR FRQ, cycle 2026-10-01. Verify on the current chart supplement before use.

Length

11,901 ft

Width

150 ft

Surface

Partially concrete/asphalt · Excellent condition

Surface treatment

Grooved

Weight bearing (lb)

S 120k · D 250k · 2D 550k · 2D/2D2 1120k

PCN

1147

Runway lights

Lighted

Airport elevation

432 ft

Published FAA baseline

Open

Published NASR record; does not reflect temporary closures or restrictions. Current operational status is the card at the top of the page.

Runway 16L/34R numbers are magnetic; the stored geometry and every wind calculation on this page are TRUE north, so they never need a variation correction. Magnetic headings use the FAA's published variation for this airport, 16.0°E (2020), the same value printed on the FAA airport diagram. Surface condition, treatment, weight bearing, thresholds and traffic pattern are from the FAA NASR record (cycle 2026-10-01); lighting, ILS and LAHSO are in their own sections above. Declared distances are not shown in this phase.

Runway percentages are measured independently. Multiple runways can be active simultaneously, so totals may exceed 100%.

Observed runway usage — 720 hours of tower TFDM runway configuration history collected · 3 distinct configurations observed · through Nov 3, 2026. Shares are the fraction of recorded hours in which the tower's TFDM configuration listed each end. Wind sectors use the wind reported when each configuration began. Nothing here is inferred from wind; the wind-favored analysis for KSEA is a separate module. 90-day, 12-month and seasonal views appear once the record is long enough.

13 departure procedures · 12 STARs · FAA hot spots page ↗ · FAA d-TPP cycle 2611. Plates open on aeronav.faa.gov (public domain); ATIS Alerts does not reproduce charts or minimums.