Lewiston/Nez Perce County to Boeing Fld/King County International LWS → BFI
227 nautical miles (262 statute miles) west on a straight line, true course 290°, about 275° magnetic at the departure end (variation 15E). At 120 knots that is 1 h 47 min at the quickest height in today's winds (16,500 ft, a 7-knot tailwind), arriving about 9:27 am PDT (16:27 UTC). Right now LWS is VFR, wind from the east-southeast (120°) at 3 knots; BFI is VFR, wind from the southeast (130°) 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: 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
- AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the first 59 nm of the route.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the first 178 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 49 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 LWS.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
No pilot reports within 50 nautical miles of the line in the last three hours.
Winds aloft along the route, and the time en route the forecast for use 14:00–21:00 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 4 forecast points nearest it (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 | 030° at 3 kt | −1 kt | -2 °C | 121 kt | 1 h 53 min | 9:33 am PDT (16:33 UTC) |
| 6,500 ft | 020° at 6 kt | 0 | -1 °C | 120 kt | 1 h 54 min | 9:34 am PDT (16:34 UTC) |
| 8,500 ft | 040° at 12 kt | −4 kt | -4 °C | 124 kt | 1 h 50 min | 9:30 am PDT (16:30 UTC) |
| 10,500 ft | 040° at 16 kt | −5 kt | -6 °C | 125 kt | 1 h 49 min | 9:29 am PDT (16:29 UTC) |
| 12,500 ft | 030° at 18 kt | −5 kt | -9 °C | 125 kt | 1 h 49 min | 9:29 am PDT (16:29 UTC) |
| 14,500 ft | 030° at 22 kt | −6 kt | -12 °C | 126 kt | 1 h 48 min | 9:28 am PDT (16:28 UTC) |
| 16,500 ft | 030° at 26 kt | −7 kt | -16 °C | 127 kt | 1 h 47 min | 9:27 am PDT (16:27 UTC) |
| 18,000 ft FL180 | 030° at 29 kt | −7 kt | -18 °C | 127 kt | 1 h 47 min | 9:27 am PDT (16:27 UTC) |
| 24,000 ft FL240 | 020° at 41 kt | +1 kt | -29 °C | 119 kt | 1 h 54 min | 9:34 am PDT (16:34 UTC) |
| 30,000 ft FL300 | 010° at 45 kt | +3 kt | -39 °C | 117 kt | 1 h 56 min | 9:36 am PDT (16:36 UTC) |
| 34,000 ft FL340 | 020° at 34 kt | 0 | -42 °C | 120 kt | 1 h 54 min | 9:34 am PDT (16:34 UTC) |
| 39,000 ft FL390 | 320° at 7 kt | +6 kt | -43 °C | 114 kt | 1 h 59 min | 9:39 am PDT (16:39 UTC) |
Based on data from the 12th at 12:00 UTC; valid on the 12th at 18:00 UTC for use 14:00 to 21:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| LWS | used from 0 nm out; 25 nm from the line | L/V | L/V -2° | 030/6 -5° | 050/10 -10° | 110/19 -21° | 150/22 -31° | 130/11 -36° | 200/6 -37° | 220/21 -40° |
| GEG | used from 49 nm out; 70 nm from the line | 060/10 -2° | 050/11 -3° | 050/9 -8° | 050/27 -19° | 040/26 -31° | 030/32 -39° | 020/19 -41° | L/V -42° | |
| YKM | used from 99 nm out; 39 nm from the line | L/V | 350/9 0° | 040/20 -5° | 030/23 -8° | 020/41 -18° | 010/74 -27° | 010/73 -40° | 020/54 -44° | 350/9 -43° |
| SEA | used from 198 nm out; 15 nm from the line | L/V | L/V 1° | 020/13 -2° | 020/27 -4° | 010/43 -14° | 360/54 -26° | 360/63 -40° | 010/60 -48° | 350/39 -50° |
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 |
|---|---|---|---|---|---|---|---|
| LWS Lewiston, ID | departure | VFR Sky: overcast at 4,300 feet | from the east-southeast (120°) at 3 knots | 10+ mi | 4,300 ft | 1,442 ft | 6:56 am PDT (13:56 UTC) |
| MWH Moses Lake, WA | 109 nm out, 17 nm northeast of the line, tower | VFR | from the north (010°) at 4 knots | 10+ mi | none | 1,188 ft | 13:52 UTC |
| ESW Easton, WA | 178 nm out, 3 nm southwest of the line | no report just now | 2,226 ft | ||||
| BFI Seattle, WA | destination | VFR | from the southeast (130°) at 3 knots | 10+ mi | none | 21 ft | 6:53 am PDT (13:53 UTC) |
The highest airport on this list sits at 2,226 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At BFI when you get there the forecast at the estimated arrival, 9:27 am PDT (16:27 UTC)
Wind light and variable, visibility more than 6 miles, clear skies VFR
The whole forecast for BFI
- From Mon 5:00 am PDT (12:00 UTC): wind light and variable, visibility more than 6 miles, clear skies
- From Mon 12:00 pm PDT (19:00 UTC): wind from the west-southwest at 4 knots, visibility more than 6 miles, clear skies
- From Mon 2:00 pm PDT (21:00 UTC): wind from the west-northwest at 5 knots, visibility more than 6 miles, clear skies
- From Mon 8:00 pm PDT (03:00 UTC): wind calm, visibility more than 6 miles, scattered clouds at 25,000 feet
- From Tue 4:00 am PDT (11:00 UTC): wind from the south-southeast at 4 knots, visibility more than 6 miles, overcast at 10,000 feet
The forecast for LWS, the departure
- From Mon 5:00 am PDT (12:00 UTC): wind light and variable, visibility more than 6 miles, a broken layer at 4,500 feet, overcast at 6,000 feet
- 30% chance between Mon 5:00 am PDT (12:00 UTC) and 10:00 am PDT (17:00 UTC): light rain showers, scattered clouds at 2,500 feet, a broken layer at 3,500 feet
- From Mon 10:00 am PDT (17:00 UTC): wind from the west at 4 knots, visibility more than 6 miles, scattered clouds at 2,500 feet, a broken layer at 3,500 feet
- From Mon 6:00 pm PDT (01:00 UTC): wind light and variable, visibility more than 6 miles, a few clouds at 10,000 feet
- From Mon 9:00 pm PDT (04:00 UTC): wind light and variable, 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 LWS 6:05 pm PDT (01:05 UTC), at BFI 6:25 pm PDT (01:25 UTC) (civil twilight ends 6:56 pm PDT (01:56 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: Lewiston/Nez Perce County, Boeing Fld/King County International.