Felts Field to Boeing Fld/King County International SFF → BFI
202 nautical miles (232 statute miles) west on a straight line, true course 269°, about 253° magnetic at the departure end (variation 16E). At 120 knots that is 1 h 32 min at the quickest height in today's winds (4,500 ft, a 12-knot tailwind), arriving about 12:21 am PDT (07:21 UTC), after sunset at the destination. Right now SFF is VFR, wind calm; BFI is VFR, wind calm. 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 ZULU 2C: moderate icing up to 23,000 ft. Over the first 77 nm of the route.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 192 nm of the route.
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 SFF.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
Not fetched just now.
Winds aloft along the route, and the time en route the forecast for use 02:00–09:00 UTC · at 120 knots true airspeed
The westbound cruising heights for this course (VFR: even 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 (GEG, YKM, SEA). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 4,500 ft | 070° at 13 kt | −12 kt | -2 °C | 132 kt | 1 h 32 min | 12:21 am PDT (07:21 UTC) |
| 6,500 ft | 060° at 14 kt | −12 kt | -2 °C | 132 kt | 1 h 32 min | 12:21 am PDT (07:21 UTC) |
| 8,500 ft | 040° at 17 kt | −12 kt | -6 °C | 132 kt | 1 h 32 min | 12:21 am PDT (07:21 UTC) |
| 10,500 ft | 040° at 18 kt | −12 kt | -8 °C | 132 kt | 1 h 32 min | 12:21 am PDT (07:21 UTC) |
| 12,500 ft | 040° at 17 kt | −12 kt | -11 °C | 132 kt | 1 h 32 min | 12:21 am PDT (07:21 UTC) |
| 14,500 ft | 030° at 16 kt | −9 kt | -14 °C | 129 kt | 1 h 34 min | 12:23 am PDT (07:23 UTC) |
| 16,500 ft | 030° at 14 kt | −7 kt | -17 °C | 127 kt | 1 h 35 min | 12:24 am PDT (07:24 UTC) |
| 18,000 ft FL180 | 020° at 13 kt | −5 kt | -19 °C | 125 kt | 1 h 37 min | 12:26 am PDT (07:26 UTC) |
| 24,000 ft FL240 | 020° at 25 kt | −9 kt | -29 °C | 129 kt | 1 h 34 min | 12:23 am PDT (07:23 UTC) |
| 30,000 ft FL300 | 360° at 39 kt | −5 kt | -37 °C | 125 kt | 1 h 37 min | 12:26 am PDT (07:26 UTC) |
| 34,000 ft FL340 | 360° at 29 kt | −4 kt | -41 °C | 124 kt | 1 h 38 min | 12:27 am PDT (07:27 UTC) |
| 39,000 ft FL390 | 320° at 11 kt | +7 kt | -41 °C | 113 kt | 1 h 47 min | 12:36 am PDT (07:36 UTC) |
Based on data from the 12th at 00:00 UTC; valid on the 12th at 06:00 UTC for use 02:00 to 09:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| GEG | used from 0 nm out; 16 nm from the line | 080/16 -2° | 050/17 -7° | 080/9 -10° | 190/33 -21° | 180/31 -32° | L/V -35° | L/V -37° | 270/8 -40° | |
| YKM | used from 96 nm out; 64 nm from the line | 070/10 | 040/15 -1° | 020/27 -8° | 030/25 -13° | 020/48 -20° | 010/83 -27° | 010/77 -37° | 010/49 -40° | 350/14 -41° |
| SEA | used from 144 nm out; 35 nm from the line | 050/7 | 050/11 1° | 050/12 -5° | 030/31 -7° | 010/61 -15° | 010/69 -26° | 360/73 -40° | 360/62 -47° | 330/21 -43° |
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 |
|---|---|---|---|---|---|---|---|
| SFF Spokane, WA | departure | VFR | calm | 10+ mi | none | 1,956 ft | 9:53 pm PDT (04:53 UTC) |
| EAT Wenatchee, WA | 115 nm out, 13 nm south of the line | VFR Sky: overcast at 9,500 feet | from the north (010°) at 7 knots | 10+ mi | 9,500 ft | 1,248 ft | 04:55 UTC |
| ESW Easton, WA | 154 nm out, 20 nm south of the line | no report just now | 2,226 ft | ||||
| BFI Seattle, WA | destination | VFR | calm | 10+ mi | none | 21 ft | 9:53 pm PDT (04:53 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 BFI when you get there the forecast at the estimated arrival, 12:21 am PDT (07:21 UTC)
Wind calm, visibility more than 6 miles, clear skies VFR
The whole forecast for BFI
- From Sun 11:00 pm PDT (06:00 UTC): wind calm, visibility more than 6 miles, clear skies
- From Mon 3:00 am PDT (10:00 UTC): wind calm, 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
- From Mon 7:00 pm PDT (02:00 UTC): wind calm, visibility more than 6 miles, clear skies
The forecast for SFF, the departure
- From Sun 11:00 pm PDT (06:00 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 12:00 pm PDT (19:00 UTC): wind light and variable, visibility more than 6 miles, a few clouds at 10,000 feet
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 SFF 6:07 pm PDT (01:07 UTC), at BFI 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 UTC)). At 120 knots the arrival at BFI is before sunrise there (7:23 am PDT (14:23 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: Felts Field, Boeing Fld/King County International.