Plan a flight · Sun 9:33 pm EDT (01:33 UTC)

Purdue University Airport to Boeing Fld/King County International LAF → BFI

1,572 nautical miles (1,809 statute miles) northwest on a straight line, true course 298°, about 299° magnetic at the departure end (variation 1W). At 120 knots that is 12 h 29 min at the quickest height in today's winds (4,500 ft, a 6-knot tailwind), arriving about 7:02 am PDT (14:02 UTC), after sunset at the destination. Right now LAF is VFR, wind calm; BFI is VFR, wind from the northwest (310°) 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

SIGMET 3W: thunderstorms (a convective SIGMET) up to 31,000 ft, moving from the southwest at 40 knots, until 10:55 pm EDT (02:55 UTC). Over the route from 895 to 975 nm out.
as issued
```
WSUS33 KKCI 120055
MKCW WST 120055
CONVECTIVE SIGMET 3W
VALID UNTIL 0255Z
MT WY
FROM 10WSW MLS-70E DDY-20N LAR-50E BPI-30NE BIL-10WSW MLS
AREA TS MOV FROM 22040KT. TOPS TO FL310.
```
AIRMET SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist), from 8:00 pm EDT (00:00 UTC). Over the route from 637 to 1313 nm out.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft, from 8:00 pm EDT (00:00 UTC). Over the route from 776 to 1313 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist), from 8:00 pm EDT (00:00 UTC). Over the route from 995 to 1373 nm out.
AIRMET ZULU 2C: moderate icing up to 14,000 ft, from 8:00 pm EDT (00:00 UTC). Over the route from 1224 to 1452 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 25,000 ft to 39,000 ft, from 8:00 pm EDT (00:00 UTC). Over the last 0 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 LAF.

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

E75L at 14,000 ft, 27 nm south, 7:22 pm EDT (23:22 UTC): moderate turbulence from 14,000 ft to 21,000 ft, remarks: during the climb zlc. 1233 nm along the route, 27 nm south of the line.
as filed, and in English
```
MSO UA /OV 32S/TM 2322/FL140/TP E75L/TB MOD 140-210/RM DURC /ZLC
```
Report
a routine report filed through MSO
Where
over 32S
Time
23:22 UTC
Height
at 14,000 ft
Aircraft
E75L
Turbulence
moderate from 14,000 ft to 21,000 ft
Remarks
during the climb zlc
E170 at 23,000 ft, 25 nm southeast, 7:14 pm EDT (23:14 UTC): light turbulence. At the departure end, 25 nm southeast of the line.
as filed, and in English
```
IND UA /OV VHP315020/TM 2314/FL230/TP E170/TB LGT
```
Report
a routine report filed through IND
Where
20 nm northwest (315°) of VHP
Time
23:14 UTC
Height
at 23,000 ft
Aircraft
E170
Turbulence
light
B39M at 35,000 ft, 45 nm northeast, 8:29 pm EDT (00:29 UTC): no turbulence, remarks: smooth. At the departure end, 45 nm northeast of the line.
as filed, and in English
```
IKK UA /OV CGT/TM 0029/FL350/TP B39M/TB NEG/RM SMOOTH
```
Report
a routine report filed through IKK
Where
over CGT
Time
00:29 UTC
Height
at 35,000 ft
Aircraft
B39M
Turbulence
none
Remarks
smooth
BE20 at 14,000 ft, 25 nm north, 8:20 pm EDT (00:20 UTC): light turbulence. 497 nm along the route, 25 nm north of the line.
as filed, and in English
```
FSD UA /OV FSD340035/TM 0020/FL140/TP BE20/TB CONS LGT/ NEG 120
```
Report
a routine report filed through FSD
Where
35 nm north (340°) of FSD
Time
00:20 UTC
Height
at 14,000 ft
Aircraft
BE20
Turbulence
continuous light no at 12,000 ft
PC12 at 100 ft, 13 nm south, 6:34 pm EDT (22:34 UTC): no icing. 637 nm along the route, 13 nm south of the line.
as filed, and in English
```
PIR UA /OV PIR/TM 2234/FL001/TP PC12/SK BASE030-TOP045/IC NEG
```
Report
a routine report filed through PIR
Where
over PIR
Time
22:34 UTC
Height
at 100 ft
Aircraft
PC12
Sky
BASE030-TOP045
Icing
none
A306 at 4,700 ft, 27 nm south, 8:51 pm EDT (00:51 UTC): a routine report with nothing remarked on. 1005 nm along the route, 27 nm south of the line.
as filed, and in English
```
BIL UA /OV BIL280001/TM 0051/FL047/TP A306/SK BASE 047
```
Report
a routine report filed through BIL
Where
1 nm west (280°) of BIL
Time
00:51 UTC
Height
at 4,700 ft
Aircraft
A306
Sky
base 4,700 ft
B738 at 24,000 ft, 46 nm south, 7:13 pm EDT (23:13 UTC): remarks: snow top flight level at 24,000 ft zlc. 1134 nm along the route, 46 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN270030/TM 2313/FL240/TP B738/RM SN TOP FL 240 /ZLC
```
Report
a routine report filed through BZN
Where
30 nm west (270°) of BZN
Time
23:13 UTC
Height
at 24,000 ft
Aircraft
B738
Remarks
snow top flight level at 24,000 ft zlc
C25B at 4,100 ft, 4 nm southwest, 8:36 pm EDT (00:36 UTC): no icing, overcast above 4,100 ft, remarks: during the descent ils runway 12. 1233 nm along the route, 4 nm southwest of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 0036/FL041/TP C25B/SK OVC041/IC NEG/RM DURD ILS RY 12
```
Report
a routine report filed through MSO
Where
over MSO
Time
00:36 UTC
Height
at 4,100 ft
Aircraft
C25B
Sky
overcast from 4,100 ft
Icing
none
Remarks
during the descent ils runway 12
PC12 at 13,500 ft, 42 nm south, 9:08 pm EDT (01:08 UTC): no turbulence, a trace of icing, overcast from 9,000 ft to 13,500 ft, -10 °C. 1432 nm along the route, 42 nm south of the line.
as filed, and in English
```
PSC UA /OV PSC360025/TM 0108/FL135/TP PC12/SK OVC090-TOP135/TA M10/TB NEG /IC TRACE RM 135-090
```
Report
a routine report filed through PSC
Where
25 nm north (360°) of PSC
Time
01:08 UTC
Height
at 13,500 ft
Aircraft
PC12
Sky
overcast from 9,000 ft, tops 13,500 ft
Temperature
−10 °C
Turbulence
none
Icing
trace remarks from 13,500 ft to 9,000 ft
PC12 at 13,000 ft, 39 nm south, 8:42 pm EDT (00:42 UTC): remarks: zse. At the destination end, 39 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
PC12 at 15,000 ft, 39 nm south, 8:42 pm EDT (00:42 UTC): remarks: zse. At the destination end, 39 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

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 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 14 forecast points nearest it (JOT, DBQ, MCW, FSD, PIR, RAP, MLS, BIL, GTF, GPI, LWS, 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	130° at 5 kt	−6 kt	7 °C	126 kt	12 h 29 min	7:02 am PDT (14:02 UTC)
6,500 ft	140° at 2 kt	−3 kt	9 °C	123 kt	12 h 47 min	7:20 am PDT (14:20 UTC)
8,500 ft	210° at 4 kt	0	6 °C	120 kt	13 h 06 min	7:39 am PDT (14:39 UTC)
10,500 ft	220° at 8 kt	+2 kt	2 °C	118 kt	13 h 19 min	7:52 am PDT (14:52 UTC)
12,500 ft	220° at 11 kt	+4 kt	-1 °C	116 kt	13 h 33 min	8:06 am PDT (15:06 UTC)
14,500 ft	230° at 14 kt	+7 kt	-5 °C	113 kt	13 h 55 min	8:28 am PDT (15:28 UTC)
16,500 ft	230° at 17 kt	+10 kt	-9 °C	110 kt	14 h 17 min	8:50 am PDT (15:50 UTC)
18,000 ft FL180	230° at 19 kt	+12 kt	-12 °C	108 kt	14 h 33 min	9:06 am PDT (16:06 UTC)
24,000 ft FL240	240° at 25 kt	+18 kt	-23 °C	102 kt	15 h 25 min	9:58 am PDT (16:58 UTC)
30,000 ft FL300	240° at 32 kt	+24 kt	-36 °C	96 kt	16 h 22 min	10:55 am PDT (17:55 UTC)
34,000 ft FL340	250° at 39 kt	+33 kt	-43 °C	87 kt	18 h 04 min	12:37 pm PDT (19:37 UTC)
39,000 ft FL390	260° at 49 kt	+45 kt	-48 °C	75 kt	20 h 58 min	3:31 pm PDT (22:31 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
JOT	used from 0 nm out; 65 nm from the line	230/11	290/12 16°	300/19 10°	320/19 4°	300/17 -9°	330/31 -20°	320/49 -37°	320/53 -45°	320/67 -49°
DBQ	used from 149 nm out; 44 nm from the line	220/23	240/22 16°	240/24 10°	260/18 5°	270/16 -8°	290/27 -19°	310/42 -35°	320/55 -44°	300/71 -52°
MCW	used from 249 nm out; 61 nm from the line	200/35	240/33 18°	250/20 10°	260/10 6°	270/18 -8°	260/28 -19°	280/30 -34°	290/49 -43°	280/70 -54°
FSD	used from 398 nm out; 54 nm from the line	200/16	220/20 17°	240/26 13°	230/19 6°	240/25 -9°	240/28 -20°	250/39 -33°	250/44 -43°	260/63 -52°
PIR	used from 547 nm out; 66 nm from the line		L/V 17°	230/13 12°	220/22 6°	250/31 -9°	250/34 -21°	240/50 -35°	230/61 -43°	240/62 -51°
RAP	used from 696 nm out; 73 nm from the line		120/15 12°	180/22 11°	220/26 5°	230/35 -9°	240/40 -22°	240/50 -37°	240/51 -41°	240/47 -47°
MLS	used from 796 nm out; 86 nm from the line		120/22 5°	170/18 4°	200/33 1°	230/49 -10°	230/58 -21°	220/54 -37°	230/64 -44°	250/74 -49°
BIL	used from 945 nm out; 38 nm from the line		080/24	130/14 -1°	180/33 0°	210/43 -10°	220/58 -21°	200/55 -36°	220/75 -44°	240/83 -48°
GTF	used from 1094 nm out; 50 nm from the line		070/21	080/18 -6°	120/5 -5°	180/30 -14°	200/53 -24°	210/80 -38°	220/83 -44°	230/68 -46°
GPI	used from 1194 nm out; 86 nm from the line		060/19 -3°	110/11 -8°	130/6 -8°	200/40 -19°	190/58 -28°	200/101 -39°	220/73 -43°	230/41 -43°
LWS	used from 1293 nm out; 61 nm from the line	010/5	050/14 -2°	040/12 -6°	160/7 -10°	190/30 -22°	200/54 -27°	200/48 -35°	210/40 -37°	230/32 -41°
GEG	used from 1343 nm out; 23 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°
YKM	used from 1442 nm out; 61 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°
SEA	used from 1492 nm out; 55 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°

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
LAF Lafayette, IN	departure	VFR	calm	10+ mi	none	605 ft	8:54 pm EDT (00:54 UTC)
VYS Peru, IL	119 nm out, 6 nm east of the line	VFR	from the east-northeast (060°) at 4 knots	10+ mi	none	654 ft	10:30 UTC
ALO Waterloo, IA	279 nm out, 9 nm northeast of the line, tower	VFR	from the south (170°) at 10 knots	10+ mi	none	873 ft	00:54 UTC
LYV Luverne, MN	458 nm out, 3 nm northeast of the line	VFR	calm	10+ mi	none	1,435 ft	01:15 UTC
FSD Sioux Falls, SD	477 nm out, 8 nm south of the line, tower	VFR Sky: scattered clouds at 18,000 feet, scattered clouds at 25,000 feet	from the west-northwest (290°) at 5 knots	10+ mi	none	1,430 ft	00:56 UTC
PIR Pierre, SD	637 nm out, 14 nm south of the line	marginal VFR Sky: a few clouds at 500 feet, overcast at 1,100 feet	from the east-northeast (070°) at 5 knots	10+ mi	1,100 ft	1,744 ft	00:53 UTC
HWQ Harlowton, MT	1054 nm out, 4 nm west of the line	no report just now				4,311 ft
MSO Missoula, MT	1233 nm out, 4 nm southwest of the line, tower	marginal VFR Sky: a few clouds at 800 feet, overcast at 2,400 feet Weather: light rain	from the north (010°) at 4 knots	7 mi	2,400 ft	3,205 ft	01:10 UTC
GEG Spokane, WA	1383 nm out, 20 nm north of the line, tower	VFR Sky: a few clouds at 4,500 feet, a broken layer at 5,500 feet, a broken layer at 10,000 feet	from the northeast (040°) at 15 knots	10+ mi	5,500 ft	2,385 ft	00:53 UTC
MWH Moses Lake, WA	1452 nm out, 12 nm south of the line, tower	VFR Sky: overcast at 10,000 feet	from the northeast (050°) at 13 knots, gusting to 18	10+ mi	10,000 ft	1,188 ft	00:52 UTC
BFI Seattle, WA	destination	VFR	from the northwest (310°) at 6 knots	10+ mi	none	21 ft	5:53 pm PDT (00:53 UTC)

The highest airport on this list sits at 4,311 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, 7:02 am PDT (14:02 UTC)

Wind light and variable, visibility more than 6 miles, patches of fog, clear skies VFR

The whole forecast for BFI

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

The forecast for LAF, the departure

From Sun 8:00 pm EDT (00:00 UTC): wind calm, visibility more than 6 miles, a few clouds at 25,000 feet
From Mon 10:00 am EDT (14:00 UTC): wind from the south-southwest at 8 knots, visibility more than 6 miles, scattered clouds at 20,000 feet
From Mon 2:00 pm EDT (18:00 UTC): wind from the southwest at 11 knots, gusting to 19, visibility more than 6 miles, scattered clouds at 20,000 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 LAF 7:12 pm EDT (23:12 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

Radar now, the central Great Lakes · loop National Weather Service

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

Radar now, the northern Rockies · 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: Purdue University Airport, Boeing Fld/King County International.