Plan a flight · Sun 10:38 pm CDT (03:38 UTC)

St. Louis Lambert International to Seattle-Tacoma International STL → SEA

1,482 nautical miles (1,705 statute miles) northwest on a straight line, true course 301°, about 302° magnetic at the departure end (variation 1W). At 120 knots that is 12 h 15 min at the quickest height in today's winds (4,500 ft, a 1-knot tailwind), arriving about 8:53 am PDT (15:53 UTC). Right now STL is VFR, wind from the south (170°) at 8 knots; SEA is VFR, wind from the north-northeast (030°) at 8 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: 1,763 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 1C: thunderstorms (a convective SIGMET) up to 30,000 ft, moving from the southwest at 40 knots, until 11:55 pm CDT (04:55 UTC). Near the route, 706 nm along the route.
as issued
```
WSUS32 KKCI 120255
MKCC WST 120255
CONVECTIVE SIGMET 1C
VALID UNTIL 0455Z
SD ND MT WY
FROM 30WSW DIK-50NW DPR-60WNW RAP-50ENE SHR-30WSW DIK
AREA TS MOV FROM 22040KT. TOPS TO FL300.
```
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). Over the route from 179 to 388 nm out.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 607 to 835 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 736 to 1134 nm out.
AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the route from 756 to 975 nm out.
AIRMET TANGO 1W: low-level wind shear (due to air speed loss or gain of 20 knots or more below 2,000 ft above the ground). Near the route, 835 nm along the route.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 835 to 955 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 835 to 1253 nm out.
AIRMET ZULU 2C: moderate icing up to 20,000 ft. Over the route from 965 to 1422 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 1024 to 1233 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 149 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 STL.

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

B763 at 32,000 ft, 43 nm north, 8:29 pm CDT (01:29 UTC): light to moderate clear-air turbulence, remarks: zdvwc. 567 nm along the route, 43 nm north of the line.
as filed, and in English
```
RAP UA /OV RAP084081/TM 0129/FL320/TP B763/TB OCNL LGT-MOD CAT/RM ZDVWC
```
Report
a routine report filed through RAP
Where
81 nm east (084°) of RAP
Time
01:29 UTC
Height
at 32,000 ft
Aircraft
B763
Turbulence
occasional light to moderate clear-air turbulence
Remarks
zdvwc
BE20 at 15,000 ft, 12 nm north, 8:56 pm CDT (01:56 UTC): -5 °C, remarks: clear out at at 22,000 ft ZDVWC-31. 706 nm along the route, 12 nm north of the line.
as filed, and in English
```
CUT UA /OV ECS340020/TM 0156/FL150/TP BE20/TA M05/IC T RIME 150-180/RM CLR OUT AT 220 ZDVWC-31
```
Report
a routine report filed through CUT
Where
20 nm north (340°) of ECS
Time
01:56 UTC
Height
at 15,000 ft
Aircraft
BE20
Temperature
−5 °C
Icing
T rime from 15,000 ft to 18,000 ft
Remarks
clear out at at 22,000 ft ZDVWC-31
UAL1076 at 30,000 ft, 47 nm south, 9:36 pm CDT (02:36 UTC): light turbulence, wind 225° at 60 knots. 845 nm along the route, 47 nm south of the line.
as filed, and in English
```
ARP UAL1076 4405N 10749W 0236 F300 225/060KT TB CONT LGT TURB IC
```
Report
a routine report filed through ARP
A306 at 4,700 ft, 40 nm northeast, 7:51 pm CDT (00:51 UTC): a routine report with nothing remarked on. 915 nm along the route, 40 nm northeast 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
E75L descending, 6 nm northeast, 8:04 pm CDT (01:04 UTC): remarks: had the airport in sight at 400-500FT above ground. 1014 nm along the route, 6 nm northeast of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 0104/FLDURD/TP E75L/RM HAD THE AIRPORT IN SIGHT AT 400-500FT AGL
```
Report
a routine report filed through BZN
Where
over BZN
Time
01:04 UTC
Height
during the descent
Aircraft
E75L
Remarks
had the airport in sight at 400-500FT above ground
CL30 at 4,200 ft, 37 nm north, 10:16 pm CDT (03:16 UTC): no icing, overcast above 4,200 ft, remarks: during the descent ils runway 12. 1144 nm along the route, 37 nm north of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 0316/FL042/TP CL30/SK OVC042/WX 2 1/2SM/IC NEG/RM DURD ILS RY 12
```
Report
a routine report filed through MSO
Where
over MSO
Time
03:16 UTC
Height
at 4,200 ft
Aircraft
CL30
Sky
overcast from 4,200 ft
Weather
2, 1/2SM
Icing
none
Remarks
during the descent ils runway 12
BCS1 at 3,700 ft, 37 nm north, 8:47 pm CDT (01:47 UTC): snow, rain, remarks: during the descent ils runway 12. 1144 nm along the route, 37 nm north of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 0147/FL037/TP BCS1/SK 037/WX SN RA/RM DURD ILS RY 12
```
Report
a routine report filed through MSO
Where
over MSO
Time
01:47 UTC
Height
at 3,700 ft
Aircraft
BCS1
Sky
at 3,700 ft
Weather
snow, rain
Remarks
during the descent ils runway 12
PC12 at 13,500 ft, 22 nm south, 8:08 pm CDT (01:08 UTC): no turbulence, a trace of icing, overcast from 9,000 ft to 13,500 ft, -10 °C. 1343 nm along the route, 22 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
SB20 at 16,000 ft, 31 nm north, 8:52 pm CDT (01:52 UTC): remarks: zse. At the destination end, 31 nm north of the line.
as filed, and in English
```
PAE UA /OV PAE075045/TM 0152/FL160/TP SB20/SK TOP120/RM ZSE
```
Report
a routine report filed through PAE
Where
45 nm east (075°) of PAE
Time
01:52 UTC
Height
at 16,000 ft
Aircraft
SB20
Sky
TOP120
Remarks
zse
PC12 at 13,000 ft, 30 nm south, 7:42 pm CDT (00:42 UTC): remarks: zse. At the destination end, 30 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, 30 nm south, 7:42 pm CDT (00:42 UTC): remarks: zse. At the destination end, 30 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
A321 at 13,500 ft, 30 nm south, 8:54 pm CDT (01:54 UTC): remarks: zse. At the destination end, 30 nm south of the line.
as filed, and in English
```
SEA UA /OV SEA120045/TM 0154/FL135/TP A321/SK TOP130/RM ZSE
```
Report
a routine report filed through SEA
Where
45 nm southeast (120°) of SEA
Time
01:54 UTC
Height
at 13,500 ft
Aircraft
A321
Sky
TOP130
Remarks
zse

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 14 forecast points nearest it (STL, COU, MKC, DSM, OMA, GRI, ONL, RAP, BIL, DLN, 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	200° at 13 kt	−1 kt	14 °C	121 kt	12 h 15 min	8:53 am PDT (15:53 UTC)
6,500 ft	210° at 11 kt	0	10 °C	120 kt	12 h 21 min	8:59 am PDT (15:59 UTC)
8,500 ft	220° at 10 kt	+1 kt	6 °C	119 kt	12 h 27 min	9:05 am PDT (16:05 UTC)
10,500 ft	220° at 13 kt	+3 kt	2 °C	117 kt	12 h 40 min	9:18 am PDT (16:18 UTC)
12,500 ft	220° at 16 kt	+5 kt	0 °C	115 kt	12 h 53 min	9:31 am PDT (16:31 UTC)
14,500 ft	220° at 18 kt	+6 kt	-5 °C	114 kt	13 h	9:38 am PDT (16:38 UTC)
16,500 ft	230° at 20 kt	+8 kt	-9 °C	112 kt	13 h 14 min	9:52 am PDT (16:52 UTC)
18,000 ft FL180	230° at 21 kt	+9 kt	-12 °C	111 kt	13 h 21 min	9:59 am PDT (16:59 UTC)
24,000 ft FL240	230° at 24 kt	+10 kt	-23 °C	110 kt	13 h 28 min	10:06 am PDT (17:06 UTC)
30,000 ft FL300	240° at 32 kt	+19 kt	-35 °C	101 kt	14 h 40 min	11:18 am PDT (18:18 UTC)
34,000 ft FL340	250° at 42 kt	+32 kt	-39 °C	88 kt	16 h 50 min	1:28 pm PDT (20:28 UTC)
39,000 ft FL390	250° at 47 kt	+36 kt	-45 °C	84 kt	17 h 39 min	2:17 pm PDT (21:17 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
STL	used from 0 nm out; 25 nm from the line	250/24	250/24 16°	260/23 9°	270/16 6°	260/25 -6°	270/29 -19°	290/34 -33°	290/48 -41°	290/54 -51°
COU	used from 50 nm out; 40 nm from the line	230/31	230/30 15°	260/16 11°	270/14 6°	260/24 -6°	270/27 -18°	270/37 -32°	280/49 -41°	290/56 -51°
MKC	used from 149 nm out; 79 nm from the line	220/44	250/28 18°	250/18 13°	240/12 6°	280/24 -6°	240/34 -18°	260/47 -30°	260/51 -40°	270/58 -50°
DSM	used from 199 nm out; 70 nm from the line	230/40	250/33 17°	250/18 12°	240/17 5°	260/28 -8°	270/34 -19°	260/41 -33°	260/55 -41°	270/62 -51°
OMA	used from 249 nm out; 25 nm from the line	220/47	240/33 19°	250/18 11°	230/17 6°	260/29 -8°	250/33 -19°	250/51 -33°	260/61 -40°	270/62 -49°
GRI	used from 348 nm out; 59 nm from the line		230/35 21°	230/23 13°	220/20 7°	240/25 -8°	240/37 -20°	250/49 -33°	260/57 -38°	260/58 -47°
ONL	used from 398 nm out; 23 nm from the line		210/31 20°	230/27 13°	230/18 7°	220/19 -8°	240/26 -20°	250/44 -35°	270/52 -39°	260/57 -47°
RAP	used from 547 nm out; 84 nm from the line		180/23 12°	200/38 13°	210/38 6°	220/28 -10°	230/34 -21°	230/37 -36°	250/52 -38°	250/59 -46°
BIL	used from 796 nm out; 96 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°
DLN	used from 995 nm out; 57 nm from the line			090/6 -6°	240/22 -4°	210/34 -16°	210/62 -25°	210/66 -34°	210/82 -36°	220/77 -42°
LWS	used from 1144 nm out; 91 nm from the line	070/10	080/12 -2°	030/12 -6°	080/7 -10°	170/34 -21°	160/46 -32°	200/33 -35°	220/22 -35°	230/18 -38°
GEG	used from 1293 nm out; 52 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 1343 nm out; 53 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 1442 nm out; 20 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
STL St Louis, MO	departure	VFR Sky: scattered clouds at 25,000 feet	from the south (170°) at 8 knots	10+ mi	none	617 ft	9:51 pm CDT (02:51 UTC)
MBY Moberly, MO	99 nm out, 12 nm southwest of the line	VFR	from the south (170°) at 4 knots	10+ mi	none	866 ft	03:35 UTC
ICL Clarinda, IA	249 nm out, 4 nm south of the line	VFR	from the south (190°) at 5 knots	10+ mi	none	995 ft	03:15 UTC
OMA Omaha, NE	298 nm out, 10 nm northeast of the line, tower	VFR Sky: a broken layer at 25,000 feet	from the south-southeast (160°) at 10 knots	10+ mi	25,000 ft	984 ft	02:52 UTC
ANW Ainsworth, NE	497 nm out, 4 nm southeast of the line	VFR	from the north-northeast (020°) at 4 knots	10+ mi	none	2,588 ft	03:15 UTC
RAP Rapid City, SD	656 nm out, 25 nm northeast of the line, tower	low IFR Sky: overcast at 300 feet Weather: mist	from the east-southeast (110°) at 4 knots	1.75 mi	300 ft	3,203 ft	03:03 UTC
GCC Gillette, WY	756 nm out, 3 nm northwest of the line	IFR Sky: a broken layer at 600 feet	from the north-northwest (330°) at 3 knots	8 mi	600 ft	4,365 ft	03:22 UTC
BZN Bozeman, MT	1014 nm out, 6 nm northeast of the line, tower	low IFR Sky: a broken layer at 200 feet, overcast at 800 feet Weather: light snow, mist	calm	1.25 mi	200 ft	4,473 ft	03:26 UTC
BTM Butte, MT	1064 nm out, 4 nm west of the line	marginal VFR Sky: a few clouds at 1,000 feet, overcast at 3,200 feet Weather: light snow, mist	from the west-northwest (300°) at 6 knots	5 mi	3,200 ft	5,550 ft	03:23 UTC
LWS Lewiston, ID	1253 nm out, 23 nm south of the line, tower	VFR Sky: overcast at 6,000 feet	from the west-northwest (300°) at 6 knots	10+ mi	6,000 ft	1,442 ft	02:56 UTC
MWH Moses Lake, WA	1363 nm out, 7 nm northeast of the line, tower	VFR Sky: scattered clouds at 8,500 feet, overcast at 11,000 feet	from the north-northwest (330°) at 3 knots	10+ mi	11,000 ft	1,188 ft	02:52 UTC
SEA Seattle, WA	destination	VFR Sky: a few clouds at 3,000 feet	from the north-northeast (030°) at 8 knots	10+ mi	none	432 ft	7:53 pm PDT (02:53 UTC)

The highest airport on this list sits at 5,550 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At SEA when you get there the forecast at the estimated arrival, 8:53 am PDT (15:53 UTC)

Wind from the southeast at 4 knots, visibility more than 6 miles, patches of fog, clear skies VFR

The whole forecast for SEA

From Sun 8:00 pm PDT (03:00 UTC): wind from the north at 6 knots, visibility more than 6 miles, clear skies
From Mon 3:00 am PDT (10:00 UTC): wind from the southeast at 4 knots, 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 4 knots, visibility more than 6 miles, clear skies
From Mon 11:00 am PDT (18:00 UTC): wind from the west at 6 knots, visibility more than 6 miles, clear skies
From Mon 8:00 pm PDT (03:00 UTC): wind from the northwest at 5 knots, visibility more than 6 miles, scattered clouds at 25,000 feet

The forecast for STL, the departure

From Sun 10:00 pm CDT (03:00 UTC): wind from the south at 6 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
From Mon 1:00 am CDT (06:00 UTC): wind from the south-southwest at 6 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
From Mon 11:00 am CDT (16:00 UTC): wind from the southwest at 12 knots, gusting to 20, visibility more than 6 miles, a few clouds at 25,000 feet

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

6/7634 CENTRALIA, MO, Monday, October 12, 2026 UTC 21 nm from the route, 80 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · today · ZKC

Daylight

Sunset at STL 6:27 pm CDT (23:27 UTC), at SEA 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 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 upper Mississippi valley · loop National Weather Service

Radar now, the northern Rockies · loop National Weather Service

Radar now, the Pacific Northwest · 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: St. Louis Lambert International, Seattle-Tacoma International.