Boeing Fld/King County International to Missoula Montana Airport BFI → MSO
337 nautical miles (387 statute miles) east on a straight line, true course 093°, about 078° magnetic at the departure end (variation 15E). At 120 knots that is 2 h 33 min at the quickest height in today's winds (39,000 ft, a 12-knot tailwind), arriving about 8:43 pm MDT (02:43 UTC), after sunset at the destination. Right now BFI is VFR, wind variable at 6 knots; MSO is marginal VFR, wind from the south (180°) at 3 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 25,000 ft to 39,000 ft. Over the first 0 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 14,000 ft. Over the last 218 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the last 139 nm of the route.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the last 79 nm of the route.
- 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 last 20 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
- E75L at 14,000 ft, 24 nm south, 4:22 pm PDT (23:22 UTC): moderate turbulence from 14,000 ft to 21,000 ft, remarks: during the climb zlc. At the destination end, 24 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, 36 nm south, 3:17 pm PDT (22:17 UTC): a trace of rime icing, 0 °C, remarks: zse. 178 nm along the route, 36 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
- B739 at 3,700 ft, 1 nm southeast, 2:58 pm PDT (21:58 UTC): overcast above 3,700 ft, remarks: during the descent ils runway 12. At the destination end, 1 nm southeast 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
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 5 forecast points nearest it (SEA, YKM, GEG, LWS, GPI). 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 | 020° at 12 kt | +3 kt | 117 kt | 2 h 53 min | 9:03 pm MDT (03:03 UTC) | |
| 5,500 ft | 040° at 15 kt | +8 kt | -2 °C | 112 kt | 3 h 01 min | 9:11 pm MDT (03:11 UTC) |
| 7,500 ft | 040° at 16 kt | +9 kt | -4 °C | 111 kt | 3 h 02 min | 9:12 pm MDT (03:12 UTC) |
| 9,500 ft | 040° at 16 kt | +10 kt | -8 °C | 110 kt | 3 h 04 min | 9:14 pm MDT (03:14 UTC) |
| 11,500 ft | 040° at 10 kt | +6 kt | -10 °C | 114 kt | 2 h 57 min | 9:07 pm MDT (03:07 UTC) |
| 13,500 ft | 040° at 9 kt | +5 kt | -14 °C | 115 kt | 2 h 56 min | 9:06 pm MDT (03:06 UTC) |
| 15,500 ft | 040° at 9 kt | +6 kt | -17 °C | 114 kt | 2 h 57 min | 9:07 pm MDT (03:07 UTC) |
| 17,500 ft | 040° at 9 kt | +6 kt | -21 °C | 114 kt | 2 h 57 min | 9:07 pm MDT (03:07 UTC) |
| 18,000 ft FL180 | 040° at 9 kt | +6 kt | -22 °C | 114 kt | 2 h 57 min | 9:07 pm MDT (03:07 UTC) |
| 24,000 ft FL240 | 360° at 15 kt | +1 kt | -29 °C | 119 kt | 2 h 50 min | 9:00 pm MDT (03:00 UTC) |
| 30,000 ft FL300 | 320° at 8 kt | −4 kt | -36 °C | 124 kt | 2 h 43 min | 8:53 pm MDT (02:53 UTC) |
| 34,000 ft FL340 | 290° at 10 kt | −8 kt | -38 °C | 128 kt | 2 h 38 min | 8:48 pm MDT (02:48 UTC) |
| 39,000 ft FL390 | 280° at 13 kt | −12 kt | -41 °C | 132 kt | 2 h 33 min | 8:43 pm MDT (02:43 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| 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; 53 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; 29 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 248 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 297 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° |
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 | variable at 6 knots | 10+ mi | none | 21 ft | 4:53 pm PDT (23:53 UTC) |
| ESW Easton, WA | 50 nm out, 14 nm south of the line | no report just now | 2,226 ft | ||||
| MWH Moses Lake, WA | 119 nm out, 11 nm south of the line, tower | VFR Sky: a broken layer at 10,000 feet | from the east-northeast (070°) at 14 knots | 10+ mi | 10,000 ft | 1,188 ft | 23:52 UTC |
| GEG Spokane, WA | 188 nm out, 22 nm north of the line, tower | VFR Sky: a broken layer at 5,500 feet, a broken layer at 7,500 feet, a broken layer at 10,000 feet | from the northeast (050°) at 14 knots | 10+ mi | 5,500 ft | 2,385 ft | 23:53 UTC |
| MSO Missoula, MT | destination | marginal VFR Sky: overcast at 3,200 feet Weather: light rain | from the south (180°) at 3 knots | 4 mi | 3,200 ft | 3,205 ft | 5:53 pm MDT (23:53 UTC) |
The highest airport on this list sits at 3,205 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At MSO when you get there the forecast at the estimated arrival, 8:43 pm MDT (02:43 UTC)
Wind from the south-southeast at 5 knots, visibility 6 miles, light rain, overcast at 2,500 feet marginal VFR
At times between Sun 7:00 pm MDT (01:00 UTC) and 11:00 pm MDT (05:00 UTC): visibility 5 miles, light rain snow, mist, overcast at 1,500 feet marginal VFR
The whole forecast for MSO
- From Sun 6:00 pm MDT (00:00 UTC): wind from the south-southeast at 5 knots, visibility 6 miles, light rain, overcast at 2,500 feet
- At times between Sun 7:00 pm MDT (01:00 UTC) and 11:00 pm MDT (05:00 UTC): visibility 5 miles, light rain snow, mist, overcast at 1,500 feet
- From Mon 12:00 am MDT (06:00 UTC): wind from the east-southeast at 5 knots, visibility more than 6 miles, showers nearby, overcast at 2,500 feet
- 30% chance between Mon 3:00 am MDT (09:00 UTC) and 6:00 am MDT (12:00 UTC): visibility 6 miles, light snow, overcast at 2,500 feet
- From Mon 6:00 am MDT (12:00 UTC): wind from the east-southeast at 8 knots, visibility more than 6 miles, overcast at 5,000 feet
The forecast for BFI, the departure
- 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
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 BFI 6:27 pm PDT (01:27 UTC), at MSO 6:54 pm MDT (00:54 UTC) (civil twilight ends 7:25 pm MDT (01:25 UTC)). At 120 knots the arrival at MSO is after sunset there (6:56 pm MDT (00:56 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: Boeing Fld/King County International, Missoula Montana Airport.