Plan a flight · Sun 11:42 pm MDT (05:42 UTC)

Joslin Fld/Magic Valley Regional to Seattle-Tacoma International TWF → SEA

446 nautical miles (513 statute miles) northwest on a straight line, true course 315°, about 302° magnetic at the departure end (variation 13E). At 120 knots that is 3 h 43 min at the quickest height in today's winds (12,500 ft, no wind along the track), arriving about 2:25 am PDT (09:25 UTC), after sunset at the destination. Right now TWF is VFR, wind from the west-southwest (250°) at 8 knots; SEA is VFR, wind from the east (090°) at 6 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 ZULU 2C: moderate icing up to 23,000 ft. Over the first 89 nm of the route.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the first 139 nm of the route.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 258 nm of the route.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 178 to 317 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 218 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 TWF.

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

E175 at 6,300 ft, 50 nm northeast, 10:20 pm MDT (04:20 UTC): overcast above 6,300 ft, remarks: during the descent runway 31. 40 nm along the route, 50 nm northeast of the line.
as filed, and in English
```
SUN UA /OV KSUN/TM 0420/FL063/TP E175/SK OVC063-TOPUNKN/RM DURD RY31
```
Report
a routine report filed through SUN
Where
over KSUN
Time
04:20 UTC
Height
at 6,300 ft
Aircraft
E175
Sky
overcast from 6,300 ft, tops unknown
Remarks
during the descent runway 31
E175 at 5,900 ft, 50 nm northeast, 9:29 pm MDT (03:29 UTC): a broken layer above 5,900 ft, remarks: during the descent runway 31. 40 nm along the route, 50 nm northeast of the line.
as filed, and in English
```
SUN UA /OV KSUN/TM 0329/FL059/TP E175/SK BKN059-TOPUNKN/RM DURD RY31
```
Report
a routine report filed through SUN
Where
over KSUN
Time
03:29 UTC
Height
at 5,900 ft
Aircraft
E175
Sky
a broken layer from 5,900 ft, tops unknown
Remarks
during the descent runway 31
E175 at 5,700 ft, 50 nm northeast, 8:59 pm MDT (02:59 UTC): a broken layer above 5,700 ft, remarks: during the descent runway 31. 40 nm along the route, 50 nm northeast of the line.
as filed, and in English
```
SUN UA /OV KSUN/TM 0259/FL057/TP E175/SK BKN057-TOPUNKN/RM DURD RY31
```
Report
a routine report filed through SUN
Where
over KSUN
Time
02:59 UTC
Height
at 5,700 ft
Aircraft
E175
Sky
a broken layer from 5,700 ft, tops unknown
Remarks
during the descent runway 31
E75L descending, 11 nm north, 10:35 pm MDT (04:35 UTC): light turbulence from 11,000 ft to 14,000 ft, light rime icing from 8,000 ft to 12,000 ft, -10 °C. 268 nm along the route, 11 nm north of the line.
as filed, and in English
```
GEG UA /OV PDT/TM 0435/FLDURD/TP E75L/TA M10/TB LT TURB 140-110/IC LT RIME 120-080
```
Report
a routine report filed through GEG
Where
over PDT
Time
04:35 UTC
Height
during the descent
Aircraft
E75L
Temperature
−10 °C
Turbulence
lt turbulence from 14,000 ft to 11,000 ft
Icing
lt rime from 12,000 ft to 8,000 ft
E75L at 1,500 ft, 30 nm northeast, 10:49 pm MDT (04:49 UTC): remarks: low-level wind shear loss of 8 knots on final. 297 nm along the route, 30 nm northeast of the line.
as filed, and in English
```
PSC UA /OV PSC120003/TM 0449/FL015/TP E75L/RM LLWS LOSS OF 8 KTS ON FINAL
```
Report
a routine report filed through PSC
Where
3 nm southeast (120°) of PSC
Time
04:49 UTC
Height
at 1,500 ft
Aircraft
E75L
Remarks
low-level wind shear loss of 8 knots on final

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 4 forecast points nearest it (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 6 kt	+1 kt	2 °C	119 kt	3 h 45 min	2:27 am PDT (09:27 UTC)
6,500 ft	020° at 8 kt	+3 kt	-1 °C	117 kt	3 h 49 min	2:31 am PDT (09:31 UTC)
8,500 ft	010° at 10 kt	+5 kt	-5 °C	115 kt	3 h 53 min	2:35 am PDT (09:35 UTC)
10,500 ft	020° at 8 kt	+3 kt	-8 °C	117 kt	3 h 49 min	2:31 am PDT (09:31 UTC)
12,500 ft	030° at 4 kt	0	-11 °C	120 kt	3 h 43 min	2:25 am PDT (09:25 UTC)
14,500 ft	light and variable	0	-14 °C	120 kt	3 h 43 min	2:25 am PDT (09:25 UTC)
16,500 ft	230° at 5 kt	0	-17 °C	120 kt	3 h 43 min	2:25 am PDT (09:25 UTC)
18,000 ft FL180	230° at 8 kt	0	-20 °C	120 kt	3 h 43 min	2:25 am PDT (09:25 UTC)
24,000 ft FL240	280° at 9 kt	+6 kt	-28 °C	114 kt	3 h 55 min	2:37 am PDT (09:37 UTC)
30,000 ft FL300	300° at 12 kt	+10 kt	-35 °C	110 kt	4 h 03 min	2:45 am PDT (09:45 UTC)
34,000 ft FL340	270° at 17 kt	+11 kt	-37 °C	109 kt	4 h 06 min	2:48 am PDT (09:48 UTC)
39,000 ft FL390	240° at 23 kt	+5 kt	-40 °C	115 kt	3 h 53 min	2:35 am PDT (09:35 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
BOI	used from 0 nm out; 75 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 198 nm out; 95 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 248 nm out; 84 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 397 nm out; 25 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
TWF Twin Falls, ID	departure	VFR Sky: scattered clouds at 4,200 feet, overcast at 5,000 feet	from the west-southwest (250°) at 8 knots	10+ mi	5,000 ft	4,153 ft	10:53 pm MDT (04:53 UTC)
GNG Gooding, ID	30 nm out, 10 nm northeast of the line	VFR Sky: scattered clouds at 3,700 feet, overcast at 4,800 feet	from the south (190°) at 7 knots	10+ mi	4,800 ft	3,732 ft	05:35 UTC
BOI Boise, ID	99 nm out, 6 nm southwest of the line, tower	VFR Sky: overcast at 8,000 feet	from the south (190°) at 4 knots	10+ mi	8,000 ft	2,871 ft	04:53 UTC
ONO Ontario, OR	139 nm out, 11 nm west of the line	VFR Sky: overcast at 8,500 feet	from the northwest (320°) at 17 knots, gusting to 26	10+ mi	8,500 ft	2,193 ft	04:53 UTC
BKE Baker City, OR	198 nm out, 5 nm north of the line	marginal VFR Sky: overcast at 2,600 feet	from the north-northwest (330°) at 9 knots, gusting to 18	10+ mi	2,600 ft	3,373 ft	04:53 UTC
LGD La Grande, OR	228 nm out, 18 nm northeast of the line	VFR Sky: overcast at 3,200 feet	from the west-northwest (290°) at 11 knots	10+ mi	3,200 ft	2,717 ft	04:56 UTC
PDT Pendleton, OR	268 nm out, 12 nm northeast of the line, tower	VFR Sky: overcast at 5,500 feet	from the north-northeast (030°) at 4 knots	10+ mi	5,500 ft	1,494 ft	04:53 UTC
YKM Yakima, WA	357 nm out, 6 nm northeast of the line, tower	VFR Sky: overcast at 9,500 feet	from the west-southwest (240°) at 5 knots	10+ mi	9,500 ft	1,098 ft	04:53 UTC
ESW Easton, WA	407 nm out, 20 nm northeast of the line	no report just now				2,226 ft
SEA Seattle, WA	destination	VFR	from the east (090°) at 6 knots	10+ mi	none	432 ft	9:53 pm PDT (04:53 UTC)

The highest airport on this list sits at 4,153 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, 2:25 am PDT (09:25 UTC)

Wind from the east-northeast at 6 knots, visibility more than 6 miles, clear skies VFR

The whole forecast for SEA

From Sun 11:00 pm PDT (06:00 UTC): wind from the east-northeast 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 south at 4 knots, visibility more than 6 miles, scattered clouds at 25,000 feet

The forecast for TWF, the departure

From Mon 12:00 am MDT (06:00 UTC): wind from the southwest at 8 knots, visibility more than 6 miles, light rain, a broken layer at 4,000 feet
From Mon 1:00 am MDT (07:00 UTC): wind from the southwest at 7 knots, visibility 5 miles, light rain, mist, scattered clouds at 1,500 feet, overcast at 2,500 feet
From Mon 10:00 am MDT (16:00 UTC): wind from the west at 7 knots, visibility 6 miles, light rain showers, mist, scattered clouds at 1,500 feet, a broken layer at 3,500 feet
From Mon 12:00 pm MDT (18:00 UTC): wind from the west-northwest at 6 knots, visibility more than 6 miles, showers nearby, scattered clouds at 4,000 feet, overcast at 8,000 feet
From Mon 8:00 pm MDT (02:00 UTC): wind from the west-southwest at 8 knots, visibility more than 6 miles, showers nearby, overcast at 4,000 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 TWF 7:00 pm MDT (01:00 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

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: Joslin Fld/Magic Valley Regional, Seattle-Tacoma International.