Plan a flight · Sun 8:56 pm MDT (02:56 UTC)

Salt Lake City International to Boeing Fld/King County International SLC → BFI

600 nautical miles (691 statute miles) northwest on a straight line, true course 316°, about 305° magnetic at the departure end (variation 11E). At 120 knots that is 4 h 53 min at the quickest height in today's winds (24,000 ft, a 3-knot tailwind), arriving about 12:49 am PDT (07:49 UTC), after sunset at the destination. Right now SLC is VFR, wind from the south (170°) at 6 knots; BFI is VFR, wind calm. 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: 33 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 2E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the first 0 nm of the route.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the first 276 nm of the route.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the first 10 nm of the route.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 433 nm of the route.
AIRMET ZULU 2C: moderate icing up to 20,000 ft. Over the route from 354 to 531 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 177 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 SLC.

Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first

A321 at 10,000 ft, 16 nm south, 6:00 pm MDT (00:00 UTC): light chop turbulence, no icing, remarks: during the descent. At the departure end, 16 nm south of the line.
as filed, and in English
```
SLC UA /OV TCH165020/TM 0000/FL100/TP A321/TB LGT CHOP/IC NEG/RM DURD
```
Report
a routine report filed through SLC
Where
20 nm south (165°) of TCH
Time
00:00 UTC
Height
at 10,000 ft
Aircraft
A321
Turbulence
light chop
Icing
none
Remarks
during the descent
B737 at 16,000 ft, 16 nm southwest, 6:45 pm MDT (00:45 UTC): no turbulence, light rime icing from 13,000 ft to 17,000 ft, 8 °C, remarks: during the climb. At the departure end, 16 nm southwest of the line.
as filed, and in English
```
SLC UA /OV TCH230020/TM 0045/FL160/TP B737/TA 8/TB NEG/IC LT RIME 130-170/RM DURC
```
Report
a routine report filed through SLC
Where
20 nm southwest (230°) of TCH
Time
00:45 UTC
Height
at 16,000 ft
Aircraft
B737
Temperature
8 °C
Turbulence
none
Icing
lt rime from 13,000 ft to 17,000 ft
Remarks
during the climb
B38M at 16,000 ft, 12 nm southwest, 6:06 pm MDT (00:06 UTC): no turbulence, no icing, 13 °C, remarks: during the climb. At the departure end, 12 nm southwest of the line.
as filed, and in English
```
SLC UA /OV TCH230015/TM 0006/FL160/TP B38M/TA 13/TB NEG/IC NEG/RM DURC
```
Report
a routine report filed through SLC
Where
15 nm southwest (230°) of TCH
Time
00:06 UTC
Height
at 16,000 ft
Aircraft
B38M
Temperature
13 °C
Turbulence
none
Icing
none
Remarks
during the climb
PC12 at 6,000 ft, 42 nm northeast, 7:09 pm MDT (01:09 UTC): scattered clouds up to 6,000 ft, remarks: multiple scattered layers during the descent runway 31. 187 nm along the route, 42 nm northeast of the line.
as filed, and in English
```
SUN UA /OV KSUN/TM 0109/FL060/TP PC12/SK SCT-TOP060/WX FV05SM/RM MULTIPLE SCT LAYERS DURD RY31
```
Report
a routine report filed through SUN
Where
over KSUN
Time
01:09 UTC
Height
at 6,000 ft
Aircraft
PC12
Sky
scattered clouds, tops 6,000 ft
Weather
flight visibility 5 miles
Remarks
multiple scattered layers during the descent runway 31
PC12 at 14,000 ft, 14 nm southwest, 8:13 pm MDT (02:13 UTC): light turbulence up to 21,000 ft, light rime icing from 10,000 ft to 14,000 ft, -10 °C. 197 nm along the route, 14 nm southwest of the line.
as filed, and in English
```
BOI UA /OV BOI117049/TM 0213/FL140/TP PC12/TA M10/TB CONS LGT 210 BLO/IC LGT RIME 140-100 /ZLC
```
Report
a routine report filed through BOI
Where
49 nm southeast (117°) of BOI
Time
02:13 UTC
Height
at 14,000 ft
Aircraft
PC12
Temperature
−10 °C
Turbulence
continuous light at 21,000 ft below
Icing
light rime from 14,000 ft to 10,000 ft zlc
PC12 at 6,000 ft, 25 nm northeast, 6:56 pm MDT (00:56 UTC): overcast above 6,000 ft. 413 nm along the route, 25 nm northeast of the line.
as filed, and in English
```
ALW UA /OV ALW200015/TM 0056/FL060/TP PC12/SK OVC060
```
Report
a routine report filed through ALW
Where
15 nm south (200°) of ALW
Time
00:56 UTC
Height
at 6,000 ft
Aircraft
PC12
Sky
overcast from 6,000 ft
PC12 at 13,500 ft, 48 nm northeast, 7:08 pm MDT (01:08 UTC): no turbulence, a trace of icing, overcast from 9,000 ft to 13,500 ft, -10 °C. 463 nm along the route, 48 nm northeast of the line.
as filed, and in English
```
PSC UA /OV PSC360025/TM 0108/FL135/TP PC12/SK OVC090-TOP135/TA M10/TB NEG /IC TRACE RM 135-090
```
Report
a routine report filed through PSC
Where
25 nm north (360°) of PSC
Time
01:08 UTC
Height
at 13,500 ft
Aircraft
PC12
Sky
overcast from 9,000 ft, tops 13,500 ft
Temperature
−10 °C
Turbulence
none
Icing
trace remarks from 13,500 ft to 9,000 ft
C337 at 12,000 ft, 11 nm southwest, 7:18 pm MDT (01:18 UTC): light rime icing, -12 °C, remarks: zse. 492 nm along the route, 11 nm southwest of the line.
as filed, and in English
```
YKM UA /OV YKM155020/TM 0118/FL120/TP C337/TA M12/IC LGT RIME/RM ZSE
```
Report
a routine report filed through YKM
Where
20 nm southeast (155°) of YKM
Time
01:18 UTC
Height
at 12,000 ft
Aircraft
C337
Temperature
−12 °C
Icing
light rime
Remarks
zse
A321 at 13,500 ft, 13 nm southwest, 7:54 pm MDT (01:54 UTC): remarks: zse. 551 nm along the route, 13 nm southwest of the line.
as filed, and in English
```
SEA UA /OV SEA120045/TM 0154/FL135/TP A321/SK TOP130/RM ZSE
```
Report
a routine report filed through SEA
Where
45 nm southeast (120°) of SEA
Time
01:54 UTC
Height
at 13,500 ft
Aircraft
A321
Sky
TOP130
Remarks
zse
PC12 at 13,000 ft, 13 nm southwest, 6:42 pm MDT (00:42 UTC): remarks: zse. 551 nm along the route, 13 nm southwest of the line.
as filed, and in English
```
YKM UA /OV YKM270050/TM 0042/FL130/TP PC12/SK TOP130/RM -ZSE
```
Report
a routine report filed through YKM
Where
50 nm west (270°) of YKM
Time
00:42 UTC
Height
at 13,000 ft
Aircraft
PC12
Sky
TOP130
Remarks
zse
PC12 at 15,000 ft, 13 nm southwest, 6:42 pm MDT (00:42 UTC): remarks: zse. 551 nm along the route, 13 nm southwest of the line.
as filed, and in English
```
YKM UA /OV YKM270050/TM 0042/FL150/TP PC12/SK TOP130/RM -ZSE
```
Report
a routine report filed through YKM
Where
50 nm west (270°) of YKM
Time
00:42 UTC
Height
at 15,000 ft
Aircraft
PC12
Sky
TOP130
Remarks
zse
SB20 at 16,000 ft, 44 nm northeast, 7:52 pm MDT (01:52 UTC): remarks: zse. At the destination end, 44 nm northeast of the line.
as filed, and in English
```
PAE UA /OV PAE075045/TM 0152/FL160/TP SB20/SK TOP120/RM ZSE
```
Report
a routine report filed through PAE
Where
45 nm east (075°) of PAE
Time
01:52 UTC
Height
at 16,000 ft
Aircraft
SB20
Sky
TOP120
Remarks
zse

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 6 forecast points nearest it (SLC, PIH, 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	030° at 3 kt	+1 kt	2 °C	119 kt	5 h 03 min	12:59 am PDT (07:59 UTC)
6,500 ft	020° at 5 kt	+2 kt	-1 °C	118 kt	5 h 05 min	1:01 am PDT (08:01 UTC)
8,500 ft	360° at 6 kt	+4 kt	-5 °C	116 kt	5 h 10 min	1:06 am PDT (08:06 UTC)
10,500 ft	360° at 4 kt	+2 kt	-6 °C	118 kt	5 h 05 min	1:01 am PDT (08:01 UTC)
12,500 ft	250° at 1 kt	0	-9 °C	120 kt	5 h	12:56 am PDT (07:56 UTC)
14,500 ft	220° at 6 kt	−1 kt	-12 °C	121 kt	4 h 58 min	12:54 am PDT (07:54 UTC)
16,500 ft	220° at 11 kt	−2 kt	-15 °C	122 kt	4 h 55 min	12:51 am PDT (07:51 UTC)
18,000 ft FL180	220° at 15 kt	−2 kt	-18 °C	122 kt	4 h 55 min	12:51 am PDT (07:51 UTC)
24,000 ft FL240	220° at 15 kt	−3 kt	-27 °C	123 kt	4 h 53 min	12:49 am PDT (07:49 UTC)
30,000 ft FL300	240° at 19 kt	+5 kt	-34 °C	115 kt	5 h 13 min	1:09 am PDT (08:09 UTC)
34,000 ft FL340	240° at 27 kt	+7 kt	-36 °C	113 kt	5 h 19 min	1:15 am PDT (08:15 UTC)
39,000 ft FL390	230° at 32 kt	+2 kt	-41 °C	118 kt	5 h 05 min	1:01 am PDT (08:01 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
SLC	used from 0 nm out; 25 nm from the line		200/5	230/8 2°	220/20 -2°	210/40 -12°	190/53 -25°	210/62 -30°	220/69 -34°	220/64 -43°
PIH	used from 98 nm out; 71 nm from the line		L/V	240/13 1°	240/15 -3°	210/42 -15°	200/70 -25°	220/74 -29°	220/71 -36°	220/62 -43°
BOI	used from 148 nm out; 80 nm from the line		300/7 2°	280/5 -4°	210/16 -9°	210/60 -20°	210/75 -29°	210/63 -32°	220/64 -32°	220/54 -39°
LWS	used from 344 nm out; 91 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°
YKM	used from 394 nm out; 90 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 541 nm out; 32 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
SLC Salt Lake City, UT	departure	VFR Sky: a few clouds at 800 feet, a broken layer at 5,000 feet, overcast at 8,000 feet Weather: light rain	from the south (170°) at 6 knots	10+ mi	5,000 ft	4,230 ft	8:30 pm MDT (02:30 UTC)
OGD Ogden, UT	20 nm out, 16 nm northeast of the line, tower	VFR Sky: overcast at 8,000 feet Weather: light rain	from the south (180°) at 6 knots	10+ mi	8,000 ft	4,472 ft	01:53 UTC
TWF Twin Falls, ID	148 nm out, 9 nm west of the line, tower	VFR Sky: overcast at 4,400 feet	from the west-southwest (240°) at 6 knots	10+ mi	4,400 ft	4,153 ft	02:53 UTC
BOI Boise, ID	256 nm out, 14 nm southwest of the line, tower	VFR Sky: a broken layer at 7,500 feet, overcast at 12,000 feet	from the southeast (130°) at 9 knots	10+ mi	7,500 ft	2,871 ft	01:53 UTC
BKE Baker City, OR	354 nm out, 3 nm southwest of the line	VFR Sky: a broken layer at 7,500 feet	from the northwest (310°) at 14 knots, gusting to 23	10+ mi	7,500 ft	3,373 ft	01:53 UTC
LGD La Grande, OR	374 nm out, 13 nm northeast of the line	VFR Sky: a broken layer at 3,400 feet, overcast at 4,500 feet	from the west-northwest (290°) at 13 knots	10+ mi	3,400 ft	2,717 ft	01:56 UTC
PDT Pendleton, OR	423 nm out, 7 nm northeast of the line, tower	VFR Sky: overcast at 7,000 feet	calm	10+ mi	7,000 ft	1,494 ft	01:53 UTC
YKM Yakima, WA	512 nm out, 4 nm southeast of the line, tower	VFR Sky: overcast at 9,500 feet	from the west-northwest (290°) at 6 knots	10+ mi	9,500 ft	1,098 ft	01:53 UTC
ESW Easton, WA	551 nm out, 16 nm northeast of the line	no report just now				2,226 ft
BFI Seattle, WA	destination	VFR	calm	10+ mi	none	21 ft	7:53 pm PDT (02:53 UTC)

The highest airport on this list sits at 4,472 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, 12:49 am PDT (07:49 UTC)

Wind light and variable, visibility more than 6 miles, clear skies VFR

The whole forecast for BFI

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

The forecast for SLC, the departure

From Sun 8:00 pm MDT (02:00 UTC): wind from the south-southeast at 8 knots, visibility more than 6 miles, light rain, scattered clouds at 2,000 feet, a broken layer at 5,000 feet
From Mon 2:00 am MDT (08:00 UTC): wind from the south at 9 knots, visibility more than 6 miles, scattered clouds at 4,000 feet, a broken layer at 8,000 feet
30% chance between Mon 2:00 am MDT (08:00 UTC) and 6:00 am MDT (12:00 UTC): wind variable at 10 knots, gusting to 25, light rain showers, a broken layer at 4,000 feet
From Mon 6:00 am MDT (12:00 UTC): wind from the south at 11 knots, visibility more than 6 miles, light rain showers, scattered clouds at 2,000 feet, a broken layer at 5,000 feet
From Mon 3:00 pm MDT (21:00 UTC): wind from the northwest at 11 knots, visibility more than 6 miles, light rain showers, scattered clouds at 2,000 feet, a broken layer at 5,000 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 SLC 6:52 pm MDT (00:52 UTC), at BFI 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 UTC)). At 120 knots the arrival at BFI 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

Radar now, the southern Rockies · loop National Weather Service

Radar now, the Pacific Northwest · loop National Weather Service

Radar, the whole country · loop National Weather Service

Surface analysis now Weather Prediction Center

Forecast chart, 12 hours ahead Weather Prediction Center

Forecast chart, 24 hours ahead Weather Prediction Center

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: Salt Lake City International, Boeing Fld/King County International.