Plan a flight · Mon 12:37 am PDT (07:37 UTC)

Boeing Fld/King County International to Willow Run Airport BFI → YIP

1,662 nautical miles (1,912 statute miles) east on a straight line, true course 087°, about 072° magnetic at the departure end (variation 15E). At 120 knots that is 10 h 04 min at the quickest height in today's winds (39,000 ft, a 45-knot tailwind), arriving about 1:41 pm EDT (17:41 UTC). Right now BFI is VFR, wind from the south-southeast (160°) at 4 knots; YIP is IFR, wind from the west (260°) at 6 knots. 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: 3 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 18,000 ft to 39,000 ft, from 11:00 pm PDT (06:00 UTC). Over the first 189 nm of the route.
AIRMET ZULU 2C: moderate icing up to 23,000 ft, from 11:00 pm PDT (06:00 UTC). Over the route from 129 to 657 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist), from 11:00 pm PDT (06:00 UTC). Over the route from 249 to 547 nm out.
AIRMET SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist), from 11:00 pm PDT (06:00 UTC). Over the route from 269 to 1094 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft, from 11:00 pm PDT (06:00 UTC). Over the route from 269 to 468 nm out.
AIRMET ZULU 2C: moderate icing up to 23,000 ft, from 11:00 pm PDT (06:00 UTC). Over the route from 667 to 677 nm out.
AIRMET TANGO 3W: low-level wind shear (due to air speed loss or gain of 20 knots or more below 2,000 ft above the ground), from 11:00 pm PDT (06:00 UTC). Over the route from 1264 to 1403 nm out.
AIRMET SIERRA 3E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist), from 11:00 pm PDT (06:00 UTC). Over the last 119 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 BFI.

Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first

B738 at 1,700 ft, 41 nm south, 11:20 pm PDT (06:20 UTC): overcast from 1,700 ft to 2,000 ft, remarks: during the descent. At the destination end, 41 nm south of the line.
as filed, and in English
```
TOL UA /OV KTOL/TM 0620/FL017/TP B738/SK OVC017-TOP020/RM DURD
```
Report
a routine report filed through TOL
Where
over KTOL
Time
06:20 UTC
Height
at 1,700 ft
Aircraft
B738
Sky
overcast from 1,700 ft, tops 2,000 ft
Remarks
during the descent
A333 descending, 8 nm east, 10:44 pm PDT (05:44 UTC): a routine report with nothing remarked on. At the destination end, 8 nm east of the line.
as filed, and in English
```
DTW UA /OV DTW/TM 0544/FLDURD/TP A333/SK TOPS 025
```
Report
a routine report filed through DTW
Where
over DTW
Time
05:44 UTC
Height
during the descent
Aircraft
A333
Sky
tops 2,500 ft
B738 at 1,800 ft, 41 nm south, 10:18 pm PDT (05:18 UTC): overcast from 1,800 ft to 2,700 ft, remarks: during the climb. At the destination end, 41 nm south of the line.
as filed, and in English
```
TOL UA /OV KTOL/TM 0518/FL018/TP B738/SK OVC018-TOP027/RM DURC
```
Report
a routine report filed through TOL
Where
over KTOL
Time
05:18 UTC
Height
at 1,800 ft
Aircraft
B738
Sky
overcast from 1,800 ft, tops 2,700 ft
Remarks
during the climb
B739 descending, 8 nm east, 9:54 pm PDT (04:54 UTC): a routine report with nothing remarked on. At the destination end, 8 nm east of the line.
as filed, and in English
```
DTW UA /OV DTW/TM 0454/FLDURD/TP B739/SK BASES 011
```
Report
a routine report filed through DTW
Where
over DTW
Time
04:54 UTC
Height
during the descent
Aircraft
B739
Sky
bases 1,100 ft
B738 at 1,300 ft, 41 nm south, 9:45 pm PDT (04:45 UTC): overcast from 1,300 ft to 3,000 ft, remarks: during the descent. At the destination end, 41 nm south of the line.
as filed, and in English
```
TOL UA /OV KTOL/TM 0445/FL013/TP B738/SK OVC013-TOP030/RM DURD
```
Report
a routine report filed through TOL
Where
over KTOL
Time
04:45 UTC
Height
at 1,300 ft
Aircraft
B738
Sky
overcast from 1,300 ft, tops 3,000 ft
Remarks
during the descent

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 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 15 forecast points nearest it (SEA, YKM, GEG, GPI, GTF, BIL, MLS, DIK, ABR, AXN, MSP, LSE, GRB, MKG, CLE). A plus sign is a headwind, a minus sign a tailwind.

Height	Average wind	Head- or tailwind	Temperature	Ground speed	Time en route	Arrival
3,500 ft	240° at 12 kt	−8 kt		128 kt	12 h 59 min	4:36 pm EDT (20:36 UTC)
5,500 ft	190° at 4 kt	+1 kt	1 °C	119 kt	13 h 58 min	5:35 pm EDT (21:35 UTC)
7,500 ft	210° at 5 kt	−1 kt	7 °C	121 kt	13 h 44 min	5:21 pm EDT (21:21 UTC)
9,500 ft	220° at 7 kt	−3 kt	3 °C	123 kt	13 h 31 min	5:08 pm EDT (21:08 UTC)
11,500 ft	220° at 12 kt	−6 kt	0 °C	126 kt	13 h 11 min	4:48 pm EDT (20:48 UTC)
13,500 ft	230° at 14 kt	−9 kt	-4 °C	129 kt	12 h 53 min	4:30 pm EDT (20:30 UTC)
15,500 ft	240° at 17 kt	−13 kt	-7 °C	133 kt	12 h 30 min	4:07 pm EDT (20:07 UTC)
17,500 ft	250° at 20 kt	−16 kt	-11 °C	136 kt	12 h 13 min	3:50 pm EDT (19:50 UTC)
18,000 ft FL180	250° at 20 kt	−17 kt	-12 °C	137 kt	12 h 08 min	3:45 pm EDT (19:45 UTC)
24,000 ft FL240	240° at 23 kt	−18 kt	-23 °C	138 kt	12 h 03 min	3:40 pm EDT (19:40 UTC)
30,000 ft FL300	250° at 26 kt	−23 kt	-37 °C	143 kt	11 h 37 min	3:14 pm EDT (19:14 UTC)
34,000 ft FL340	260° at 36 kt	−34 kt	-42 °C	154 kt	10 h 48 min	2:25 pm EDT (18:25 UTC)
39,000 ft FL390	260° at 47 kt	−45 kt	-47 °C	165 kt	10 h 04 min	1:41 pm EDT (17:41 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
SEA	used from 0 nm out; 26 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°
YKM	used from 50 nm out; 61 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°
GEG	used from 99 nm out; 69 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°
GPI	used from 249 nm out; 67 nm from the line		070/19 -5°	100/16 -7°	080/10 -8°	130/8 -19°	170/37 -28°	200/50 -40°	210/43 -40°	220/41 -42°
GTF	used from 398 nm out; 20 nm from the line		070/11	080/15 -7°	110/19 -9°	190/25 -14°	200/34 -23°	200/54 -39°	220/66 -40°	220/77 -44°
BIL	used from 547 nm out; 87 nm from the line		080/13	180/9 -2°	210/38 0°	220/51 -11°	210/46 -22°	210/58 -35°	230/73 -39°	230/72 -45°
MLS	used from 597 nm out; 63 nm from the line		150/23 2°	190/29 4°	210/44 2°	220/32 -10°	210/36 -21°	200/48 -37°	230/63 -40°	240/71 -47°
DIK	used from 746 nm out; 25 nm from the line		150/24 7°	200/38 6°	220/53 0°	230/51 -9°	230/49 -21°	240/37 -37°	240/47 -44°	250/65 -48°
ABR	used from 895 nm out; 77 nm from the line	070/14	250/10 17°	270/16 11°	260/28 5°	260/36 -10°	260/41 -22°	270/33 -37°	260/42 -42°	260/50 -48°
AXN	used from 1045 nm out; 45 nm from the line	100/14	250/21 14°	240/24 12°	240/31 5°	260/36 -10°	260/40 -21°	250/42 -36°	260/48 -45°	260/53 -50°
MSP	used from 1144 nm out; 43 nm from the line	230/26	240/30 17°	240/24 12°	250/22 5°	250/35 -10°	260/36 -21°	250/41 -36°	250/49 -45°	260/58 -52°
LSE	used from 1244 nm out; 54 nm from the line	230/40	240/24 17°	240/13 10°	250/13 6°	280/22 -9°	250/28 -21°	250/41 -34°	260/42 -44°	270/62 -53°
GRB	used from 1393 nm out; 47 nm from the line	250/36	270/23 16°	270/14 9°	240/18 4°	280/26 -9°	280/29 -20°	290/42 -36°	290/51 -45°	290/72 -55°
MKG	used from 1443 nm out; 63 nm from the line	260/22	290/16 15°	300/11 10°	290/5 3°	300/26 -9°	300/32 -20°	320/48 -36°	320/61 -45°	310/74 -53°
CLE	used from 1642 nm out; 100 nm from the line	340/7	010/16 13°	350/18 8°	350/20 3°	340/31 -10°	340/46 -21°	340/54 -37°	330/62 -44°	340/65 -49°

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 south-southeast (160°) at 4 knots	10+ mi	none	21 ft	11:53 pm PDT (06:53 UTC)
MWH Moses Lake, WA	119 nm out, 24 nm south of the line, tower	VFR Sky: a few clouds at 12,000 feet	from the north (010°) at 4 knots	10+ mi	none	1,188 ft	06:52 UTC
GEG Spokane, WA	189 nm out, 4 nm east of the line, tower	VFR Sky: a few clouds at 7,000 feet, a broken layer at 10,000 feet	from the north-northeast (030°) at 8 knots	10+ mi	10,000 ft	2,385 ft	06:53 UTC
GTF Great Falls, MT	448 nm out, 5 nm west of the line, tower	marginal VFR Sky: a few clouds at 300 feet, overcast at 1,200 feet Weather: light snow, mist	from the north-northwest (340°) at 8 knots	5 mi	1,200 ft	3,680 ft	06:53 UTC
JDN Jordan, MT	627 nm out, 13 nm north of the line	reported, no category	from the north-northeast (030°) at 8 knots		none	2,667 ft	06:48 UTC
DIK Dickinson, ND	796 nm out, 8 nm north of the line	low IFR Sky: overcast at 400 feet	from the east-northeast (060°) at 7 knots	10+ mi	400 ft	2,592 ft	06:56 UTC
BIS Bismarck, ND	876 nm out, 24 nm north of the line, tower	IFR Sky: overcast at 800 feet Weather: light rain	from the east-northeast (060°) at 8 knots	10+ mi	800 ft	1,661 ft	06:52 UTC
MOX Morris, MN	1085 nm out, 4 nm east of the line	low IFR Sky: overcast at 400 feet Weather: mist	from the northwest (320°) at 9 knots	6 mi	400 ft	1,135 ft	07:25 UTC
STP St Paul, MN	1214 nm out, 3 nm east of the line, tower	VFR	from the southeast (140°) at 6 knots	10+ mi	none	705 ft	06:53 UTC
OSH Oshkosh, WI	1423 nm out, 12 nm north of the line, tower	VFR	from the south-southwest (200°) at 10 knots	10+ mi	none	808 ft	06:53 UTC
GRR Grand Rapids, MI	1562 nm out, 3 nm southeast of the line, tower	VFR	from the southeast (140°) at 5 knots	7 mi	none	793 ft	06:53 UTC
YIP Detroit, MI	destination	IFR Sky: overcast at 900 feet	from the west (260°) at 6 knots	10+ mi	900 ft	715 ft	2:53 am EDT (06:53 UTC)

The highest airport on this list sits at 3,680 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At YIP when you get there the forecast at the estimated arrival, 1:41 pm EDT (17:41 UTC)

Wind from the southwest at 12 knots, gusting to 22, visibility more than 6 miles, a broken layer at 25,000 feet VFR

The whole forecast for YIP

From Mon 2:00 am EDT (06:00 UTC): wind light and variable, visibility more than 6 miles, overcast at 1,500 feet
From Mon 3:00 am EDT (07:00 UTC): wind from the south-southwest at 4 knots, visibility 5 miles, mist, a broken layer at 25,000 feet
At times between Mon 5:00 am EDT (09:00 UTC) and 9:00 am EDT (13:00 UTC): visibility ¾ mile, mist, a broken layer at 300 feet
From Mon 10:00 am EDT (14:00 UTC): wind from the southwest at 9 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
From Mon 1:00 pm EDT (17:00 UTC): wind from the southwest at 12 knots, gusting to 22, visibility more than 6 miles, a broken layer at 25,000 feet
From Mon 8:00 pm EDT (00:00 UTC): wind from the south-southwest at 6 knots, visibility more than 6 miles, scattered clouds at 9,000 feet, a broken layer at 20,000 feet

The forecast for BFI, the departure

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

Temporary flight restrictions on the line or within 25 nm of it

6/6656 ANOKA, MN, Monday, October 5, 2026 through Monday, October 19, 2026 Local 12 nm from the route, 1204 nm along the route · security · until 19 October · ZMP

Daylight

Sunset at BFI 6:25 pm PDT (01:25 UTC), at YIP 6:57 pm EDT (22:57 UTC) (civil twilight ends 7:25 pm EDT (23:25 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

Radar now, the Pacific Northwest · loop National Weather Service

Radar now, the northern Rockies · loop National Weather Service

Radar now, the upper Mississippi valley · loop National Weather Service

Radar, the whole country · loop National Weather Service

Surface analysis now Weather Prediction Center

Forecast chart, 12 hours ahead Weather Prediction Center

Forecast chart, 24 hours ahead Weather Prediction Center

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, Willow Run Airport.