Northern Colorado Regional to Boeing Fld/King County International FNL → BFI
857 nautical miles (986 statute miles) northwest on a straight line, true course 305°, about 296° magnetic at the departure end (variation 9E). At 120 knots that is 7 h 05 min at the quickest height in today's winds (16,500 ft, a 1-knot tailwind), arriving about 12:26 pm PDT (19:26 UTC). Right now FNL is VFR, wind from the southwest (230°) at 3 knots; BFI is VFR, wind from the southeast (140°) at 4 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: 2 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 4W: moderate turbulence above 18,000 ft (due to mountain wave) from 34,000 ft to 43,000 ft. Over the first 179 nm of the route.
- AIRMET TANGO 2W: moderate turbulence below 18,000 ft (due to mountain wave) up to 22,000 ft. Over the first 120 nm of the route.
- 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 30 to 129 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 40 to 677 nm out.
- AIRMET TANGO 5W: strong surface winds (30 knots or more) (due to sustained surface winds greater than 30 knots). Over the route from 100 to 139 nm out.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 110 to 478 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 329 to 618 nm out.
- AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the route from 488 to 677 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the route from 538 to 827 nm out.
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 FNL.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- B38M at 21,000 ft, 36 nm southwest, 5:24 am MDT (11:24 UTC): light to moderate chop turbulence, remarks: during the climb zdvwc. At the departure end, 36 nm southwest of the line.
as filed, and in English
DEN UA /OV DEN277039/TM 1124/FL210/TP B38M/TB LGT-MOD CHOP BLO 180 NEG ABV 180/RM DURC. ZDVWC
- Report
- a routine report filed through DEN
- Where
- 39 nm west (277°) of DEN
- Time
- 11:24 UTC
- Height
- at 21,000 ft
- Aircraft
- B38M
- Turbulence
- light to moderate chop below 18,000 ft no above 18,000 ft
- Remarks
- during the climb zdvwc
- B763 at 23,000 ft, 34 nm southwest, 4:26 am MDT (10:26 UTC): light chop turbulence, remarks: zdvwc. At the departure end, 34 nm southwest of the line.
as filed, and in English
DEN UA /OV DEN278037/TM 1026/FL230/TP B763/TB OCNL LGT CHOP/RM ZDVWC
- Report
- a routine report filed through DEN
- Where
- 37 nm west (278°) of DEN
- Time
- 10:26 UTC
- Height
- at 23,000 ft
- Aircraft
- B763
- Turbulence
- occasional light chop
- Remarks
- zdvwc
- CRJ2 at 24,000 ft, 6 nm southwest, 5:45 am MDT (11:45 UTC): no turbulence, remarks: ZDVWC-13. At the departure end, 6 nm southwest of the line.
as filed, and in English
DEN UA /OV DEN314057/TM 1145/FL240/TP CRJ2/TB NEG/RM ZDVWC-13
- Report
- a routine report filed through DEN
- Where
- 57 nm northwest (314°) of DEN
- Time
- 11:45 UTC
- Height
- at 24,000 ft
- Aircraft
- CRJ2
- Turbulence
- none
- Remarks
- ZDVWC-13
- CRJ2 at 19,000 ft, 14 nm southwest, 5:49 am MDT (11:49 UTC): no turbulence, remarks: ZDVWC-13. 40 nm along the route, 14 nm southwest of the line.
as filed, and in English
DEN UA /OV DEN304074/TM 1149/FL190/TP CRJ2/TB NEG/RM ZDVWC-13
- Report
- a routine report filed through DEN
- Where
- 74 nm northwest (304°) of DEN
- Time
- 11:49 UTC
- Height
- at 19,000 ft
- Aircraft
- CRJ2
- Turbulence
- none
- Remarks
- ZDVWC-13
Winds aloft along the route, and the time en route the forecast for use 08:00–15:00 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 (DEN, RKS, LND, PIH, DLN, BOI, LWS, 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 | 010° at 5 kt | +2 kt | 1 °C | 118 kt | 7 h 16 min | 12:37 pm PDT (19:37 UTC) |
| 6,500 ft | 010° at 6 kt | +2 kt | -2 °C | 118 kt | 7 h 16 min | 12:37 pm PDT (19:37 UTC) |
| 8,500 ft | 260° at 3 kt | +2 kt | -1 °C | 118 kt | 7 h 16 min | 12:37 pm PDT (19:37 UTC) |
| 10,500 ft | 230° at 6 kt | +1 kt | -3 °C | 119 kt | 7 h 12 min | 12:33 pm PDT (19:33 UTC) |
| 12,500 ft | 220° at 9 kt | +1 kt | -6 °C | 119 kt | 7 h 12 min | 12:33 pm PDT (19:33 UTC) |
| 14,500 ft | 220° at 11 kt | 0 | -9 °C | 120 kt | 7 h 08 min | 12:29 pm PDT (19:29 UTC) |
| 16,500 ft | 210° at 13 kt | −1 kt | -13 °C | 121 kt | 7 h 05 min | 12:26 pm PDT (19:26 UTC) |
| 18,000 ft FL180 | 210° at 15 kt | −1 kt | -16 °C | 121 kt | 7 h 05 min | 12:26 pm PDT (19:26 UTC) |
| 24,000 ft FL240 | 230° at 23 kt | +4 kt | -26 °C | 116 kt | 7 h 23 min | 12:44 pm PDT (19:44 UTC) |
| 30,000 ft FL300 | 230° at 29 kt | +7 kt | -34 °C | 113 kt | 7 h 35 min | 12:56 pm PDT (19:56 UTC) |
| 34,000 ft FL340 | 230° at 35 kt | +10 kt | -37 °C | 110 kt | 7 h 47 min | 1:08 pm PDT (20:08 UTC) |
| 39,000 ft FL390 | 230° at 39 kt | +11 kt | -43 °C | 109 kt | 7 h 52 min | 1:13 pm PDT (20:13 UTC) |
Based on data from the 12th at 06:00 UTC; valid on the 12th at 12:00 UTC for use 08:00 to 15:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| DEN | used from 0 nm out; 61 nm from the line | 270/24 11° | 230/13 5° | 230/48 -8° | 230/46 -20° | 230/63 -30° | 240/78 -36° | 240/78 -48° | ||
| RKS | used from 100 nm out; 81 nm from the line | 250/9 | 230/21 -1° | 210/43 -14° | 220/59 -23° | 220/55 -32° | 220/53 -35° | 220/48 -44° | ||
| LND | used from 199 nm out; 24 nm from the line | 240/10 3° | 240/30 0° | 220/42 -13° | 230/52 -23° | 220/54 -33° | 220/52 -36° | 220/53 -44° | ||
| PIH | used from 299 nm out; 74 nm from the line | 070/8 | 150/19 1° | 180/32 -4° | 210/44 -17° | 210/37 -28° | 210/74 -31° | 220/68 -35° | 220/60 -43° | |
| DLN | used from 398 nm out; 62 nm from the line | 190/10 -4° | 220/23 -4° | 210/21 -18° | 210/43 -28° | 210/60 -33° | 210/72 -37° | 210/67 -44° | ||
| BOI | used from 498 nm out; 104 nm from the line | 320/11 1° | 280/8 -5° | 220/14 -11° | 200/60 -19° | 190/66 -31° | 210/46 -32° | 220/50 -33° | 220/43 -39° | |
| LWS | used from 548 nm out; 66 nm from the line | L/V | 340/5 -3° | L/V -6° | 040/7 -10° | 100/23 -22° | 180/30 -31° | 190/11 -34° | 200/11 -36° | 220/23 -40° |
| YKM | used from 697 nm out; 51 nm from the line | 360/6 | 360/11 -1° | 030/20 -7° | 040/21 -11° | 020/55 -18° | 010/84 -26° | 010/79 -40° | 010/45 -42° | 350/23 -42° |
| SEA | used from 797 nm out; 34 nm from the line | 350/5 | 010/6 0° | 010/9 -4° | 010/27 -6° | 010/51 -15° | 360/58 -26° | 360/60 -41° | 350/55 -48° | 340/30 -45° |
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 |
|---|---|---|---|---|---|---|---|
| FNL Fort Collins/Loveland, CO | departure | VFR | from the southwest (230°) at 3 knots | 10+ mi | none | 5,020 ft | 5:56 am MDT (11:56 UTC) |
| SAA Saratoga, WY | 100 nm out, 3 nm north of the line | reported, no category | calm | 10+ mi | none | 7,014 ft | 11:50 UTC |
| LND Lander, WY | 219 nm out, 23 nm northeast of the line | marginal VFR Sky: overcast at 1,400 feet | from the northwest (320°) at 5 knots | 10+ mi | 1,400 ft | 5,588 ft | 12:15 UTC |
| JAC Jackson, WY | 319 nm out, 17 nm northeast of the line, tower | VFR Sky: overcast at 11,000 feet | from the north (010°) at 6 knots | 10+ mi | 11,000 ft | 6,451 ft | 11:56 UTC |
| IDA Idaho Falls, ID | 369 nm out, 19 nm south of the line, tower | IFR Sky: a few clouds at 1,800 feet, a broken layer at 2,900 feet, overcast at 3,700 feet Weather: heavy rain, mist | from the west-northwest (300°) at 5 knots | 2.5 mi | 2,900 ft | 4,743 ft | 12:15 UTC |
| LLJ Challis, ID | 478 nm out, 13 nm south of the line | marginal VFR Sky: a few clouds at 1,700 feet, a broken layer at 2,600 feet, overcast at 4,600 feet Weather: light rain | from the north (010°) at 3 knots | 10+ mi | 2,600 ft | 5,075 ft | 11:55 UTC |
| GIC Grangeville, ID | 588 nm out, 24 nm northeast of the line | marginal VFR Sky: a broken layer at 1,700 feet, overcast at 2,200 feet | from the southwest (230°) at 3 knots | 10+ mi | 1,700 ft | 3,313 ft | 11:55 UTC |
| ALW Walla Walla, WA | 667 nm out, 9 nm southwest of the line, tower | VFR Sky: overcast at 6,000 feet | from the south-southwest (200°) at 7 knots | 10+ mi | 6,000 ft | 1,194 ft | 11:53 UTC |
| PSC Pasco, WA | 707 nm out, 15 nm south of the line, tower | VFR Sky: overcast at 9,000 feet | from the northwest (320°) at 4 knots | 10+ mi | 9,000 ft | 410 ft | 11:53 UTC |
| ELN Ellensburg, WA | 777 nm out, 3 nm north of the line | VFR | from the northeast (050°) at 3 knots | 10+ mi | none | 1,763 ft | 11:53 UTC |
| BFI Seattle, WA | destination | VFR | from the southeast (140°) at 4 knots | 10+ mi | none | 21 ft | 4:53 am PDT (11:53 UTC) |
The highest airport on this list sits at 7,014 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, 12:26 pm PDT (19:26 UTC)
Wind from the west-southwest at 4 knots, 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
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 FNL 6:23 pm MDT (00:23 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: Northern Colorado Regional, Boeing Fld/King County International.