Boeing Fld/King County International to Felts Field BFI → SFF
202 nautical miles (232 statute miles) east on a straight line, true course 086°, about 071° magnetic at the departure end (variation 15E). At 120 knots that is 1 h 35 min at the quickest height in today's winds (39,000 ft, a 7-knot tailwind), arriving about 8:09 pm PDT (03:09 UTC), after sunset at the destination. Right now BFI is VFR, wind from the northwest (310°) at 6 knots; SFF is VFR, wind from the northeast (050°) at 12 knots, gusting to 19. For planning, not a briefing: the legal preflight briefing comes from Flight Service (1-800-WX-BRIEF) or the FAA's own tools. Airlines fly this pair: 506 flights in the DOT's last twelve reported months, the route's page.
The route the straight line, the warnings crossed, restrictions, pilot reports and the airports along the way · click a mark for its words
Green, blue, red and purple airport dots are the flying conditions reported there now (VFR, marginal VFR, IFR, low IFR); grey means no report. Red areas are SIGMETs, orange areas AIRMETs, hatched red areas temporary flight restrictions. Map tiles: OpenFreeMap, data © OpenStreetMap contributors.
Warnings the route crosses SIGMETs and AIRMETs whose area the line passes through or comes within 25 nm of
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 25,000 ft to 39,000 ft, from 5:00 pm PDT (00:00 UTC). Over the first 0 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 14,000 ft, from 5:00 pm PDT (00:00 UTC). Over the last 77 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist), from 5:00 pm PDT (00:00 UTC). Near the route, at the destination end.
A SIGMET warns of weather hazardous to all aircraft; an AIRMET of weather that matters to small aircraft and to flying without instruments. "From 60 to 180 nm out" is measured along the route from BFI.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- PC12 at 15,000 ft, 42 nm south, 5:42 pm PDT (00:42 UTC): remarks: zse. 29 nm along the route, 42 nm south of the line.
as filed, and in English
YKM UA /OV YKM270050/TM 0042/FL150/TP PC12/SK TOP130/RM -ZSE
- Report
- a routine report filed through YKM
- Where
- 50 nm west (270°) of YKM
- Time
- 00:42 UTC
- Height
- at 15,000 ft
- Aircraft
- PC12
- Sky
- TOP130
- Remarks
- zse
- PC12 at 13,000 ft, 42 nm south, 5:42 pm PDT (00:42 UTC): remarks: zse. 29 nm along the route, 42 nm south of the line.
as filed, and in English
YKM UA /OV YKM270050/TM 0042/FL130/TP PC12/SK TOP130/RM -ZSE
- Report
- a routine report filed through YKM
- Where
- 50 nm west (270°) of YKM
- Time
- 00:42 UTC
- Height
- at 13,000 ft
- Aircraft
- PC12
- Sky
- TOP130
- Remarks
- zse
Winds aloft along the route, and the time en route the forecast for use 20:00–03:00 UTC · at 120 knots true airspeed
The eastbound cruising heights for this course (VFR: odd thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 3 forecast points nearest it (SEA, YKM, GEG). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 5,500 ft | 030° at 15 kt | +9 kt | -2 °C | 111 kt | 1 h 49 min | 8:23 pm PDT (03:23 UTC) |
| 7,500 ft | 040° at 17 kt | +11 kt | -4 °C | 109 kt | 1 h 51 min | 8:25 pm PDT (03:25 UTC) |
| 9,500 ft | 040° at 17 kt | +12 kt | -8 °C | 108 kt | 1 h 52 min | 8:26 pm PDT (03:26 UTC) |
| 11,500 ft | 030° at 12 kt | +7 kt | -10 °C | 113 kt | 1 h 47 min | 8:21 pm PDT (03:21 UTC) |
| 13,500 ft | 030° at 13 kt | +7 kt | -14 °C | 113 kt | 1 h 47 min | 8:21 pm PDT (03:21 UTC) |
| 15,500 ft | 030° at 16 kt | +9 kt | -18 °C | 111 kt | 1 h 49 min | 8:23 pm PDT (03:23 UTC) |
| 17,500 ft | 030° at 19 kt | +11 kt | -21 °C | 109 kt | 1 h 51 min | 8:25 pm PDT (03:25 UTC) |
| 18,000 ft FL180 | 030° at 20 kt | +11 kt | -22 °C | 109 kt | 1 h 51 min | 8:25 pm PDT (03:25 UTC) |
| 24,000 ft FL240 | 010° at 29 kt | +7 kt | -29 °C | 113 kt | 1 h 47 min | 8:21 pm PDT (03:21 UTC) |
| 30,000 ft FL300 | 360° at 25 kt | +1 kt | -36 °C | 119 kt | 1 h 42 min | 8:16 pm PDT (03:16 UTC) |
| 34,000 ft FL340 | 350° at 17 kt | 0 | -38 °C | 120 kt | 1 h 41 min | 8:15 pm PDT (03:15 UTC) |
| 39,000 ft FL390 | 320° at 11 kt | −7 kt | -41 °C | 127 kt | 1 h 35 min | 8:09 pm PDT (03:09 UTC) |
Based on data from the 11th at 18:00 UTC; valid on the 12th at 00:00 UTC for use 20:00 to 03:00 UTC; temperatures above 24,000 ft are below zero. Heights are above sea level; a height is left out when the forecast has no wind for it over most of the line (the ground is higher). Ground speed is the airspeed less the headwind; the time en route is for the straight line and ignores climb, descent and routing around weather.
The forecast points as issued
| Point | From | 3,000 | 6,000 | 9,000 | 12,000 | 18,000 | 24,000 | 30,000 | 34,000 | 39,000 |
|---|---|---|---|---|---|---|---|---|---|---|
| SEA | used from 0 nm out; 25 nm from the line | 360/9 | 350/10 1° | 010/10 -5° | 030/20 -11° | 020/60 -17° | 010/86 -26° | 360/90 -40° | 010/68 -42° | 360/31 -43° |
| YKM | used from 48 nm out; 62 nm from the line | 030/16 | 020/18 0° | 030/30 -8° | 030/23 -13° | 020/40 -23° | 010/73 -29° | 010/54 -36° | 360/29 -37° | 330/16 -40° |
| GEG | used from 96 nm out; 73 nm from the line | 050/18 -2° | 060/19 -8° | L/V -11° | 160/11 -24° | 190/17 -31° | 200/19 -35° | 220/14 -37° | 250/11 -41° |
The weather now: both ends and the airports along the way public airports with a weather report within 25 nm of the line, one for each stretch
| Airport | Where | Conditions | Wind | Visibility | Ceiling | Elevation | Reported |
|---|---|---|---|---|---|---|---|
| BFI Seattle, WA | departure | VFR | from the northwest (310°) at 6 knots | 10+ mi | none | 21 ft | 5:53 pm PDT (00:53 UTC) |
| ESW Easton, WA | 48 nm out, 20 nm south of the line | no report just now | 2,226 ft | ||||
| EAT Wenatchee, WA | 86 nm out, 13 nm south of the line | VFR Sky: overcast at 9,000 feet | variable at 5 knots | 10+ mi | 9,000 ft | 1,248 ft | 00:55 UTC |
| SFF Spokane, WA | destination | VFR Sky: overcast at 6,500 feet | from the northeast (050°) at 12 knots, gusting to 19 | 10+ mi | 6,500 ft | 1,956 ft | 5:53 pm PDT (00:53 UTC) |
The highest airport on this list sits at 2,226 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At SFF when you get there the forecast at the estimated arrival, 8:09 pm PDT (03:09 UTC)
Wind from the northeast at 8 knots, visibility more than 6 miles, a broken layer at 8,000 feet VFR
The whole forecast for SFF
- From Sun 5:00 pm PDT (00:00 UTC): wind from the north-northeast at 13 knots, gusting to 23, visibility more than 6 miles, a broken layer at 8,000 feet
- From Sun 7:00 pm PDT (02:00 UTC): wind from the northeast at 8 knots, visibility more than 6 miles, a broken layer at 8,000 feet
- From Mon 3:00 am PDT (10:00 UTC): wind from the northeast at 3 knots, visibility more than 6 miles, a few clouds at 8,000 feet
- From Mon 8:00 am PDT (15:00 UTC): wind light and variable, visibility more than 6 miles, a few clouds at 10,000 feet
The forecast for BFI, the departure
- From Sun 5:00 pm PDT (00:00 UTC): wind from the north-northwest at 8 knots, gusting to 18, visibility more than 6 miles, a few clouds at 5,000 feet
- From Sun 7:00 pm PDT (02:00 UTC): wind light and variable, visibility more than 6 miles, clear skies
- From Mon 3:00 am PDT (10:00 UTC): wind light and variable, visibility more than 6 miles, patches of fog, clear skies
- From Mon 9:00 am PDT (16:00 UTC): wind from the south-southeast at 3 knots, visibility more than 6 miles, clear skies
- From Mon 12:00 pm PDT (19:00 UTC): wind from the west-southwest at 3 knots, visibility more than 6 miles, clear skies
- From Mon 2:00 pm PDT (21:00 UTC): wind from the west at 5 knots, visibility more than 6 miles, clear skies
Temporary flight restrictions on the line or within 25 nm of it
No temporary flight restriction on or near this route right now.
Daylight
Sunset at BFI 6:27 pm PDT (01:27 UTC), at SFF 6:07 pm PDT (01:07 UTC) (civil twilight ends 6:38 pm PDT (01:38 UTC)). At 120 knots the arrival at SFF is after sunset there (6:09 pm PDT (01:09 UTC)).
Each restriction opens the FAA's own page with the exact area, heights and times. Ordinary notices to air missions (closed runways, lights out) are not shown: the FAA's notice search is not open to sites like this one at this time.
Radar and forecast charts for the regions crossed government pictures, the latest each time the page loads
Sources: the Aviation Weather Center's data service (SIGMETs, AIRMETs, graphical AIRMETs, pilot reports, winds and temperatures aloft, observations and terminal forecasts), the National Weather Service radar, the Weather Prediction Center's charts, the FAA's temporary flight restriction list and shapes, and the FAA's airport file for the positions, elevations and magnetic variation. Fetched when the page is viewed and kept a few minutes. Each leg is the straight line between its two airports; airways, terrain and airspace are not considered. The airports in detail: Boeing Fld/King County International, Felts Field.