Billings Logan International to Seattle-Tacoma International BIL → SEA
575 nautical miles (662 statute miles) west on a straight line, true course 285°, about 275° magnetic at the departure end (variation 10E). At 120 knots that is 4 h 23 min at the quickest height in today's winds (4,500 ft, a 11-knot tailwind), arriving about 1:00 am PDT (08:00 UTC), after sunset at the destination. Right now BIL is marginal VFR, wind from the north (360°) at 10 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: 1,823 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 SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the first 278 nm of the route.
- AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the first 0 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 347 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 20,000 ft. Over the route from 69 to 516 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 119 to 327 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 159 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 BIL.
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 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 7 forecast points nearest it (BIL, GTF, 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 | 070° at 12 kt | −11 kt | -2 °C | 131 kt | 4 h 23 min | 1:00 am PDT (08:00 UTC) |
| 6,500 ft | 060° at 13 kt | −10 kt | -2 °C | 130 kt | 4 h 25 min | 1:02 am PDT (08:02 UTC) |
| 8,500 ft | 050° at 11 kt | −7 kt | -6 °C | 127 kt | 4 h 32 min | 1:09 am PDT (08:09 UTC) |
| 10,500 ft | 060° at 5 kt | −4 kt | -7 °C | 124 kt | 4 h 38 min | 1:15 am PDT (08:15 UTC) |
| 12,500 ft | 180° at 4 kt | −2 kt | -8 °C | 122 kt | 4 h 43 min | 1:20 am PDT (08:20 UTC) |
| 14,500 ft | 190° at 8 kt | −1 kt | -12 °C | 121 kt | 4 h 45 min | 1:22 am PDT (08:22 UTC) |
| 16,500 ft | 200° at 12 kt | +1 kt | -15 °C | 119 kt | 4 h 50 min | 1:27 am PDT (08:27 UTC) |
| 18,000 ft FL180 | 200° at 15 kt | +1 kt | -17 °C | 119 kt | 4 h 50 min | 1:27 am PDT (08:27 UTC) |
| 24,000 ft FL240 | 200° at 15 kt | 0 | -27 °C | 120 kt | 4 h 48 min | 1:25 am PDT (08:25 UTC) |
| 30,000 ft FL300 | 230° at 16 kt | +7 kt | -36 °C | 113 kt | 5 h 05 min | 1:42 am PDT (08:42 UTC) |
| 34,000 ft FL340 | 230° at 27 kt | +16 kt | -38 °C | 104 kt | 5 h 32 min | 2:09 am PDT (09:09 UTC) |
| 39,000 ft FL390 | 230° at 35 kt | +21 kt | -42 °C | 99 kt | 5 h 48 min | 2:25 am PDT (09:25 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| BIL | used from 0 nm out; 25 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° | |
| GTF | used from 99 nm out; 71 nm from the line | 070/11 | 080/15 -7° | 110/19 -9° | 190/25 -14° | 200/34 -23° | 200/54 -39° | 220/66 -40° | 220/77 -44° | |
| DLN | used from 149 nm out; 73 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 248 nm out; 88 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 347 nm out; 34 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 446 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 546 nm out; 15 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 |
|---|---|---|---|---|---|---|---|
| BIL Billings, MT | departure | marginal VFR Sky: overcast at 1,000 feet Weather: light rain, light snow | from the north (360°) at 10 knots | 10+ mi | 1,000 ft | 3,662 ft | 8:53 pm MDT (02:53 UTC) |
| HWQ Harlowton, MT | 60 nm out, 24 nm north of the line | no report just now | 4,311 ft | ||||
| HLN Helena, MT | 149 nm out, 13 nm north of the line, tower | IFR Sky: a broken layer at 900 feet, overcast at 1,600 feet Weather: light snow, mist | from the west-northwest (300°) at 7 knots | 1.5 mi | 900 ft | 3,877 ft | 03:14 UTC |
| MSO Missoula, MT | 238 nm out, 14 nm north of the line, tower | IFR Sky: a few clouds at 600 feet, overcast at 1,900 feet Weather: light snow, mist | calm | 2.5 mi | 1,900 ft | 3,205 ft | 02:53 UTC |
| PUW Pullman/Moscow, WA | 357 nm out, 18 nm south of the line | VFR Sky: overcast at 5,000 feet | from the north-northeast (030°) at 5 knots | 10+ mi | 5,000 ft | 2,566 ft | 02:53 UTC |
| MWH Moses Lake, WA | 456 nm out, 4 nm southeast 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 |
| EPH Ephrata, WA | 466 nm out, 6 nm northeast of the line | VFR Sky: overcast at 9,500 feet | from the north-northwest (340°) at 3 knots | 10+ mi | 9,500 ft | 1,276 ft | 02:53 UTC |
| ESW Easton, WA | 526 nm out, 8 nm southwest of the line | no report just now | 2,226 ft | ||||
| 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 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 SEA when you get there the forecast at the estimated arrival, 1:00 am PDT (08:00 UTC)
Wind from the north at 6 knots, visibility more than 6 miles, 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 BIL, the departure
- From Sun 8:00 pm MDT (02:00 UTC): wind from the north-northeast at 11 knots, visibility 3 miles, light snow, mist, overcast at 500 feet
- From Sun 9:00 pm MDT (03:00 UTC): wind from the north at 8 knots, visibility 2 miles, light snow, mist, freezing fog, a broken layer at 500 feet
- From Mon 8:00 am MDT (14:00 UTC): wind from the north-northwest at 5 knots, visibility 6 miles, mist, showers nearby, scattered clouds at 300 feet, a broken layer at 700 feet and more above
- From Mon 3:00 pm MDT (21:00 UTC): wind from the northeast at 6 knots, visibility 6 miles, mist, overcast at 1,500 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 BIL 6:33 pm MDT (00:33 UTC), at SEA 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 UTC)). At 120 knots the arrival at SEA 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
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: Billings Logan International, Seattle-Tacoma International.