Plan a flight · Sun 5:46 pm PDT (00:46 UTC)

Seattle-Tacoma International to Purdue University Airport SEA → LAF

1,572 nautical miles (1,809 statute miles) east on a straight line, true course 092°, about 076° magnetic at the departure end (variation 16E). At 120 knots that is 9 h 32 min at the quickest height in today's winds (39,000 ft, a 45-knot tailwind), arriving about 6:18 am EDT (10:18 UTC), after sunset at the destination. 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: 1 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 W70W: thunderstorms (a convective SIGMET) up to 32,000 ft, moving from the southwest at 40 knots, until 6:55 pm PDT (01:55 UTC). Over the route from 657 to 667 nm out.

as issued

WSUS33 KKCI 112355
MKCW WST 112355
CONVECTIVE SIGMET 70W
VALID UNTIL 0155Z
MT WY
FROM 30SSW MLS-60WNW BFF-40SSE OCS-10S BPI-10S BIL-30SSW MLS
AREA TS MOV FROM 22040KT. TOPS TO FL320.

AIRMET ZULU 2C: moderate icing up to 14,000 ft. Over the route from 119 to 348 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 199 to 587 nm out.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 259 to 796 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). Over the route from 269 to 935 nm out.
AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Near the route, 557 nm along 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 SEA.

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

E75L at 14,000 ft, 23 nm south, 4:22 pm PDT (23:22 UTC): moderate turbulence from 14,000 ft to 21,000 ft, remarks: during the climb zlc. 338 nm along the route, 23 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
C172 at 5,500 ft, 34 nm south, 3:17 pm PDT (22:17 UTC): a trace of rime icing, 0 °C, remarks: zse. 179 nm along the route, 34 nm south of the line.
as filed, and in English
```
PUW UA /OV PUW250030/TM 2217/FL055/TP C172/TA 00/IC TRACE RIME/RM -ZSE
```
Report
a routine report filed through PUW
Where
30 nm west (250°) of PUW
Time
22:17 UTC
Height
at 5,500 ft
Aircraft
C172
Temperature
0 °C
Icing
trace rime
Remarks
zse
C25B at 4,100 ft, 1 nm west, 5:36 pm PDT (00:36 UTC): no icing, overcast above 4,100 ft, remarks: during the descent ils runway 12. 338 nm along the route, 1 nm west 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
B739 at 3,700 ft, 1 nm west, 2:58 pm PDT (21:58 UTC): overcast above 3,700 ft, remarks: during the descent ils runway 12. 338 nm along the route, 1 nm west of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 2158/FL037/TP B739/SK OVC037/RM DURD ILS RY 12
```
Report
a routine report filed through MSO
Where
over MSO
Time
21:58 UTC
Height
at 3,700 ft
Aircraft
B739
Sky
overcast from 3,700 ft
Remarks
during the descent ils runway 12
B738 at 24,000 ft, 43 nm south, 4:13 pm PDT (23:13 UTC): remarks: snow top flight level at 24,000 ft zlc. 438 nm along the route, 43 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
B737 descending, 47 nm south, 5:28 pm PDT (00:28 UTC): scattered clouds above 8,000 ft, fog, snow, remarks: broke out about 100FT above mins. 468 nm along the route, 47 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 0028/FLDURD/TP B737/SK SCT080/WX 1/2SM SN FG/RM BROKE OUT ABOUT 100FT ABOVE MINS
```
Report
a routine report filed through BZN
Where
over BZN
Time
00:28 UTC
Height
during the descent
Aircraft
B737
Sky
scattered clouds from 8,000 ft
Weather
1/2SM, snow, fog
Remarks
broke out about 100FT above mins
PC12 at 100 ft, 11 nm south, 3:34 pm PDT (22:34 UTC): no icing. 935 nm along the route, 11 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
A21N at 34,000 ft, 9 nm southwest, 3:01 pm PDT (22:01 UTC): light chop turbulence. 1303 nm along the route, 9 nm southwest of the line.
as filed, and in English
```
ALO UA /OV ALO180020/TM 2201/FL340/TP A21N/TB CONS LGT CHOP
```
Report
a routine report filed through ALO
Where
20 nm south (180°) of ALO
Time
22:01 UTC
Height
at 34,000 ft
Aircraft
A21N
Turbulence
continuous light chop
B39M at 35,000 ft, 46 nm northeast, 5:29 pm PDT (00:29 UTC): no turbulence, remarks: smooth. At the destination end, 46 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
E170 at 23,000 ft, 25 nm southeast, 4:14 pm PDT (23:14 UTC): light turbulence. At the destination 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

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 15 forecast points nearest it (SEA, YKM, GEG, LWS, GPI, GTF, BIL, MLS, RAP, PIR, FSD, MCW, DBQ, JOT, IND). 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	110° at 3 kt	+4 kt	8 °C	116 kt	13 h 33 min	10:19 am EDT (14:19 UTC)
7,500 ft	190° at 2 kt	+1 kt	8 °C	119 kt	13 h 13 min	9:59 am EDT (13:59 UTC)
9,500 ft	220° at 5 kt	−1 kt	3 °C	121 kt	13 h	9:46 am EDT (13:46 UTC)
11,500 ft	220° at 9 kt	−3 kt	1 °C	123 kt	12 h 47 min	9:33 am EDT (13:33 UTC)
13,500 ft	230° at 12 kt	−6 kt	-3 °C	126 kt	12 h 29 min	9:15 am EDT (13:15 UTC)
15,500 ft	230° at 14 kt	−8 kt	-7 °C	128 kt	12 h 17 min	9:03 am EDT (13:03 UTC)
17,500 ft	230° at 17 kt	−10 kt	-11 °C	130 kt	12 h 06 min	8:52 am EDT (12:52 UTC)
18,000 ft FL180	240° at 17 kt	−11 kt	-12 °C	131 kt	12 h	8:46 am EDT (12:46 UTC)
24,000 ft FL240	250° at 24 kt	−18 kt	-23 °C	138 kt	11 h 23 min	8:09 am EDT (12:09 UTC)
30,000 ft FL300	250° at 31 kt	−24 kt	-36 °C	144 kt	10 h 55 min	7:41 am EDT (11:41 UTC)
34,000 ft FL340	250° at 39 kt	−33 kt	-42 °C	153 kt	10 h 16 min	7:02 am EDT (11:02 UTC)
39,000 ft FL390	260° at 49 kt	−45 kt	-48 °C	165 kt	9 h 32 min	6:18 am EDT (10:18 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 50 nm out; 49 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 149 nm out; 31 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°
LWS	used from 249 nm out; 70 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°
GPI	used from 298 nm out; 82 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°
GTF	used from 348 nm out; 85 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°
BIL	used from 497 nm out; 57 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°
MLS	used from 647 nm out; 39 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°
RAP	used from 746 nm out; 88 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°
PIR	used from 846 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°
FSD	used from 995 nm out; 76 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°
MCW	used from 1194 nm out; 36 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°
DBQ	used from 1293 nm out; 58 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°
JOT	used from 1443 nm out; 42 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°
IND	used from 1542 nm out; 65 nm from the line	320/10	350/30 16°	350/32 10°	350/30 4°	340/31 -10°	340/42 -21°	340/49 -37°	320/46 -41°	320/47 -47°

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	Elevation
SEA Seattle, WA	departure	no report just now	432 ft
MWH Moses Lake, WA	119 nm out, 8 nm south of the line, tower	no report just now	1,188 ft
GEG Spokane, WA	189 nm out, 25 nm north of the line, tower	no report just now	2,385 ft
MSO Missoula, MT	338 nm out, 1 nm west of the line, tower	no report just now	3,205 ft
BIL Billings, MT	577 nm out, 23 nm south of the line, tower	no report just now	3,662 ft
PIR Pierre, SD	935 nm out, 12 nm south of the line	no report just now	1,744 ft
FSD Sioux Falls, SD	1094 nm out, 6 nm south of the line, tower	no report just now	1,430 ft
CAV Clarion, IA	1234 nm out, 4 nm south of the line	no report just now	1,156 ft
ALO Waterloo, IA	1293 nm out, 10 nm northeast of the line, tower	no report just now	873 ft
VYS Peru, IL	1453 nm out, 7 nm northeast of the line	no report just now	654 ft
LAF Lafayette, IN	destination	no report just now	605 ft

The highest airport on this list sits at 3,662 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At LAF when you get there the forecast at the estimated arrival, 6:18 am EDT (10:18 UTC)

LAF has no terminal forecast; use the nearest airport that does.

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 SEA 6:27 pm PDT (01:27 UTC), at LAF 7:12 pm EDT (23:12 UTC) (civil twilight ends 7:40 pm EDT (23:40 UTC)). At 120 knots the arrival at LAF is before sunrise there (7:55 am EDT (11:55 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: Seattle-Tacoma International, Purdue University Airport.