St. Louis Lambert International to Boise Air Trml/Gowen Field STL → BOI
1,199 nautical miles (1,379 statute miles) west on a straight line, true course 292°, about 293° magnetic at the departure end (variation 1W). At 120 knots that is 10 h at the quickest height in today's winds (4,500 ft, no wind along the track), arriving about 4:20 am MDT (10:20 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: 6 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 8:55 pm CDT (01:55 UTC). Over the route from 699 to 909 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.
- SIGMET W71W: thunderstorms (a convective SIGMET) up to 27,000 ft, moving from the south at 40 knots, until 8:55 pm CDT (01:55 UTC). Over the route from 1009 to 1029 nm out.
as issued
WSUS33 KKCI 112355 MKCW WST 112355 CONVECTIVE SIGMET 71W VALID UNTIL 0155Z WY UT ID FROM 40S DBS-40WNW BPI-30WSW MTU-30SSW DTA-30SE TWF-40S DBS AREA EMBD TS MOV FROM 20040KT. TOPS TO FL270.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the last 639 nm of the route.
- AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the route from 699 to 1009 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 749 to 1179 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). Over the route from 759 to 989 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 889 to 1159 nm out.
- AIRMET ZULU 3C: moderate icing up to 22,000 ft. Over the last 300 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
Not fetched just now.
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 9 forecast points nearest it (STL, COU, MKC, OMA, GRI, BFF, LND, PIH, BOI). 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 | 0 | 13 °C | 120 kt | 10 h | 4:20 am MDT (10:20 UTC) |
| 6,500 ft | 210° at 14 kt | +3 kt | 14 °C | 117 kt | 10 h 15 min | 4:35 am MDT (10:35 UTC) |
| 8,500 ft | 210° at 19 kt | +6 kt | 10 °C | 114 kt | 10 h 31 min | 4:51 am MDT (10:51 UTC) |
| 10,500 ft | 220° at 21 kt | +9 kt | 6 °C | 111 kt | 10 h 48 min | 5:08 am MDT (11:08 UTC) |
| 12,500 ft | 220° at 24 kt | +11 kt | 3 °C | 109 kt | 11 h | 5:20 am MDT (11:20 UTC) |
| 14,500 ft | 220° at 26 kt | +13 kt | -1 °C | 107 kt | 11 h 12 min | 5:32 am MDT (11:32 UTC) |
| 16,500 ft | 220° at 29 kt | +16 kt | -6 °C | 104 kt | 11 h 32 min | 5:52 am MDT (11:52 UTC) |
| 18,000 ft FL180 | 230° at 31 kt | +18 kt | -9 °C | 102 kt | 11 h 45 min | 6:05 am MDT (12:05 UTC) |
| 24,000 ft FL240 | 230° at 34 kt | +20 kt | -20 °C | 100 kt | 11 h 59 min | 6:19 am MDT (12:19 UTC) |
| 30,000 ft FL300 | 230° at 39 kt | +23 kt | -33 °C | 97 kt | 12 h 22 min | 6:42 am MDT (12:42 UTC) |
| 34,000 ft FL340 | 240° at 50 kt | +40 kt | -40 °C | 80 kt | 14 h 59 min | 9:19 am MDT (15:19 UTC) |
| 39,000 ft FL390 | 260° at 56 kt | +51 kt | -48 °C | 69 kt | 17 h 23 min | 11:43 am MDT (17:43 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| STL | used from 0 nm out; 25 nm from the line | 210/13 | 260/16 17° | 270/21 10° | 280/24 5° | 310/20 -7° | 320/22 -18° | 320/44 -33° | 320/59 -43° | 310/69 -51° |
| COU | used from 50 nm out; 29 nm from the line | 210/16 | 220/19 15° | 240/33 10° | 250/29 7° | 280/21 -6° | 280/19 -18° | 300/34 -31° | 300/40 -42° | 300/60 -52° |
| MKC | used from 150 nm out; 52 nm from the line | 200/28 | 220/30 16° | 270/20 11° | 280/22 7° | 260/27 -6° | 270/27 -18° | 280/38 -32° | 270/38 -40° | 280/50 -52° |
| OMA | used from 250 nm out; 57 nm from the line | 190/34 | 230/34 19° | 250/25 12° | 250/18 6° | 250/22 -7° | 250/28 -19° | 260/34 -32° | 260/39 -41° | 280/56 -51° |
| GRI | used from 350 nm out; 15 nm from the line | 210/31 19° | 240/21 14° | 240/17 6° | 260/27 -7° | 260/34 -18° | 240/45 -32° | 250/56 -40° | 260/62 -51° | |
| BFF | used from 499 nm out; 109 nm from the line | 120/24 | 180/31 13° | 210/26 7° | 230/25 -7° | 240/41 -20° | 230/52 -36° | 250/56 -41° | 260/57 -45° | |
| LND | used from 749 nm out; 93 nm from the line | 180/33 10° | 190/50 3° | 210/59 -9° | 200/50 -21° | 190/41 -34° | 230/55 -39° | 240/65 -47° | ||
| PIH | used from 949 nm out; 66 nm from the line | 270/10 | 270/13 1° | 210/16 -2° | 200/56 -11° | 200/51 -23° | 200/68 -33° | 220/77 -37° | 230/73 -44° | |
| BOI | used from 1099 nm out; 75 nm from the line | 330/14 4° | 230/5 -2° | 220/20 -7° | 210/37 -20° | 200/59 -26° | 200/67 -34° | 210/73 -35° | 220/62 -41° |
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 | no report just now | 617 ft | ||||
| MYJ Mexico, MO | 70 nm out, 3 nm southwest of the line | no report just now | 822 ft | ||||
| STJ St Joseph, MO | 220 nm out, 18 nm south of the line, tower | no report just now | 826 ft | ||||
| LNK Lincoln, NE | 320 nm out, 16 nm north of the line, tower | no report just now | 1,218 ft | ||||
| GRI Grand Island, NE | 390 nm out, 2 nm northeast of the line, tower | no report just now | 1,847 ft | ||||
| AIA Alliance, NE | 599 nm out, 10 nm north of the line | no report just now | 3,930 ft | ||||
| GUR Guernsey, WY | 689 nm out, 2 nm northeast of the line, tower | no report just now | 4,401 ft | ||||
| CPR Casper, WY | 769 nm out, 23 nm north of the line, tower | no report just now | 5,344 ft | ||||
| LND Lander, WY | 869 nm out, 2 nm southeast of the line | no report just now | 5,588 ft | ||||
| IDA Idaho Falls, ID | 1019 nm out, 17 nm north of the line, tower | no report just now | 4,743 ft | ||||
| SUN Hailey, ID | 1119 nm out, 6 nm northeast of the line, tower | no report just now | 5,319 ft | ||||
| BOI Boise, ID | destination | no report just now | 2,871 ft |
The highest airport on this list sits at 5,588 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At BOI when you get there the forecast at the estimated arrival, 4:20 am MDT (10:20 UTC)
BOI has no terminal forecast; use the nearest airport that does.
Temporary flight restrictions on the line or within 25 nm of it
- 6/7634 CENTRALIA, MO, Monday, October 12, 2026 UTC 9 nm from the route, 90 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · today · ZKC
Daylight
Sunset at STL 6:29 pm CDT (23:29 UTC), at BOI 7:06 pm MDT (01:06 UTC) (civil twilight ends 7:35 pm MDT (01:35 UTC)). At 120 knots the arrival at BOI is before sunrise there (7:55 am MDT (13:55 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
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, Boise Air Trml/Gowen Field.