Plan a flight · Mon 1:44 am PDT (08:44 UTC)

Boeing Fld/King County International to Alexandria International BFI → AEX

1,672 nautical miles (1,924 statute miles) southeast on a straight line, true course 115°, about 100° magnetic at the departure end (variation 15E). At 120 knots that is 11 h 37 min at the quickest height in today's winds (34,000 ft, a 24-knot tailwind), arriving about 3:21 pm CDT (20:21 UTC). Right now BFI is VFR, wind calm; AEX 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: 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 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the route from 30 to 438 nm out.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 159 to 259 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 199 to 826 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 269 to 517 nm out.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 448 to 796 nm out.
AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the route from 617 to 985 nm out.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 42,000 ft. Over the route from 647 to 955 nm out.
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 706 to 905 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 736 to 746 nm out.
AIRMET TANGO 3W: 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 1055 to 1373 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 BFI.

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

B737 at 18,000 ft, 26 nm northeast, 12:24 am PDT (07:24 UTC): moderate turbulence, remarks: FL180-130. 846 nm along the route, 26 nm northeast of the line.
as filed, and in English
```
DEN UA /OV DEN330050/TM 0724/FL180/TP B737/TB MOD/RM FL180-130
```
Report
a routine report filed through DEN
Where
50 nm northwest (330°) of DEN
Time
07:24 UTC
Height
at 18,000 ft
Aircraft
B737
Turbulence
moderate
Remarks
FL180-130
A321 at 31,000 ft, 41 nm southwest, 11:41 pm PDT (06:41 UTC): moderate turbulence, remarks: mtw +/-15KT zdvwc. 925 nm along the route, 41 nm southwest of the line.
as filed, and in English
```
COS UA /OV BRK/TM 0641/FL310/TP A321/TB MOD/RM MTW +/-15KT. ZDVWC
```
Report
a routine report filed through COS
Where
over BRK
Time
06:41 UTC
Height
at 31,000 ft
Aircraft
A321
Turbulence
moderate
Remarks
mtw +/-15KT zdvwc
A20N at 25,000 ft, 34 nm southwest, 11:19 pm PDT (06:19 UTC): light chop turbulence up to 26,000 ft, remarks: during the climb ZDVWC-06. 866 nm along the route, 34 nm southwest of the line.
as filed, and in English
```
DEN UA /OV DEN250045/TM 0619/FL250/TP A20N/TB OCNL LGT CHOP BLO 260/RM DURC. ZDVWC-06
```
Report
a routine report filed through DEN
Where
45 nm west (250°) of DEN
Time
06:19 UTC
Height
at 25,000 ft
Aircraft
A20N
Turbulence
occasional light chop below 26,000 ft
Remarks
during the climb ZDVWC-06
B737 descending, 3 nm northwest, 1:10 am PDT (08:10 UTC): light chop turbulence. 895 nm along the route, 3 nm northwest of the line.
as filed, and in English
```
DEN UA /OV DEN/TM 0810/FLDURD/TP B737/TB LGT CHOP
```
Report
a routine report filed through DEN
Where
over DEN
Time
08:10 UTC
Height
during the descent
Aircraft
B737
Turbulence
light chop
B737 descending, 3 nm northwest, 12:10 am PDT (07:10 UTC): remarks: smooth. 895 nm along the route, 3 nm northwest of the line.
as filed, and in English
```
DEN UA /OV DEN/TM 0710/FLDURD/TP B737/RM SMOOTH
```
Report
a routine report filed through DEN
Where
over DEN
Time
07:10 UTC
Height
during the descent
Aircraft
B737
Remarks
smooth
B738 descending, 3 nm northwest, 11:15 pm PDT (06:15 UTC): light chop turbulence. 895 nm along the route, 3 nm northwest of the line.
as filed, and in English
```
DEN UA /OV DEN/TM 0615/FLDURD/TP B738/TB LGT CHOP
```
Report
a routine report filed through DEN
Where
over DEN
Time
06:15 UTC
Height
during the descent
Aircraft
B738
Turbulence
light chop
A21N at 33,000 ft, 41 nm southwest, 11:59 pm PDT (06:59 UTC): light chop turbulence, remarks: mtw a 10-knot loss of airspeed 100FT zdvwc. 925 nm along the route, 41 nm southwest of the line.
as filed, and in English
```
COS UA /OV BRK/TM 0659/FL330/TP A21N/TB LGT CHOP/RM MTW +/-10KT 100FT. ZDVWC
```
Report
a routine report filed through COS
Where
over BRK
Time
06:59 UTC
Height
at 33,000 ft
Aircraft
A21N
Turbulence
light chop
Remarks
mtw a 10-knot loss of airspeed 100FT zdvwc

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 eastbound cruising heights for this course (VFR: odd thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 16 forecast points nearest it (SEA, YKM, LWS, BOI, DLN, PIH, LND, RKS, DEN, PUB, GLD, GCK, GAG, OKC, DAL, SHV). A plus sign is a headwind, a minus sign a tailwind.

Height	Average wind	Head- or tailwind	Temperature	Ground speed	Time en route	Arrival
5,500 ft	230° at 16 kt	−3 kt	18 °C	123 kt	13 h 36 min	5:20 pm CDT (22:20 UTC)
7,500 ft	240° at 14 kt	−5 kt	8 °C	125 kt	13 h 23 min	5:07 pm CDT (22:07 UTC)
9,500 ft	240° at 13 kt	−5 kt	5 °C	125 kt	13 h 23 min	5:07 pm CDT (22:07 UTC)
11,500 ft	240° at 14 kt	−4 kt	2 °C	124 kt	13 h 29 min	5:13 pm CDT (22:13 UTC)
13,500 ft	230° at 16 kt	−4 kt	-2 °C	124 kt	13 h 29 min	5:13 pm CDT (22:13 UTC)
15,500 ft	230° at 19 kt	−4 kt	-7 °C	124 kt	13 h 29 min	5:13 pm CDT (22:13 UTC)
17,500 ft	230° at 21 kt	−3 kt	-11 °C	123 kt	13 h 36 min	5:20 pm CDT (22:20 UTC)
18,000 ft FL180	230° at 22 kt	−3 kt	-12 °C	123 kt	13 h 36 min	5:20 pm CDT (22:20 UTC)
24,000 ft FL240	230° at 28 kt	−7 kt	-22 °C	127 kt	13 h 10 min	4:54 pm CDT (21:54 UTC)
30,000 ft FL300	250° at 40 kt	−19 kt	-31 °C	139 kt	12 h 02 min	3:46 pm CDT (20:46 UTC)
34,000 ft FL340	250° at 41 kt	−24 kt	-37 °C	144 kt	11 h 37 min	3:21 pm CDT (20:21 UTC)
39,000 ft FL390	250° at 39 kt	−24 kt	-46 °C	144 kt	11 h 37 min	3:21 pm CDT (20:21 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
SEA	used from 0 nm out; 24 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°
YKM	used from 50 nm out; 26 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°
LWS	used from 149 nm out; 62 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°
BOI	used from 298 nm out; 97 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°
DLN	used from 348 nm out; 86 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°
PIH	used from 448 nm out; 53 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°
LND	used from 547 nm out; 77 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°
RKS	used from 647 nm out; 30 nm from the line			250/9	230/21 -1°	210/43 -14°	220/59 -23°	220/55 -32°	220/53 -35°	220/48 -44°
DEN	used from 796 nm out; 69 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°
PUB	used from 945 nm out; 70 nm from the line			260/45 11°	240/38 6°	230/47 -8°	230/51 -19°	240/74 -29°	240/82 -35°	250/72 -48°
GLD	used from 995 nm out; 64 nm from the line		260/37	260/25 14°	250/27 8°	230/36 -8°	230/49 -21°	250/71 -30°	260/82 -36°	250/73 -48°
GCK	used from 1045 nm out; 45 nm from the line		240/40 22°	240/40 14°	240/38 7°	230/39 -7°	230/45 -20°	250/73 -28°	260/74 -36°	260/64 -49°
GAG	used from 1144 nm out; 41 nm from the line		240/35 22°	240/27 14°	230/25 6°	240/38 -7°	230/44 -19°	250/73 -28°	270/66 -37°	270/58 -49°
OKC	used from 1244 nm out; 52 nm from the line	220/43	230/31 17°	260/13 16°	270/11 7°	240/20 -6°	250/32 -17°	260/60 -28°	280/50 -37°	290/45 -50°
DAL	used from 1393 nm out; 88 nm from the line	190/30	200/28 18°	220/18 13°	250/13 8°	240/24 -6°	270/20 -14°	270/35 -29°	290/34 -39°	310/41 -51°
SHV	used from 1492 nm out; 61 nm from the line	210/20	210/20 18°	230/20 11°	240/16 7°	270/17 -7°	250/11 -15°	300/34 -30°	310/34 -40°	320/36 -51°

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
BFI Seattle, WA	departure	VFR	calm	10+ mi	none	21 ft	12:53 am PDT (07:53 UTC)
PSC Pasco, WA	149 nm out, 11 nm south of the line, tower	VFR Sky: overcast at 9,500 feet	from the north-northwest (330°) at 6 knots	10+ mi	9,500 ft	410 ft	07:53 UTC
ALW Walla Walla, WA	189 nm out, 5 nm southwest of the line, tower	VFR Sky: a broken layer at 8,000 feet	from the south-southeast (160°) at 6 knots	10+ mi	8,000 ft	1,194 ft	07:53 UTC
IDA Idaho Falls, ID	497 nm out, 8 nm west of the line, tower	marginal VFR Sky: overcast at 1,700 feet	from the north (360°) at 3 knots	10+ mi	1,700 ft	4,743 ft	07:53 UTC
BPI Big Piney, WY	597 nm out, 7 nm southwest of the line	VFR Sky: a broken layer at 3,300 feet	from the southeast (140°) at 4 knots	10+ mi	3,300 ft	6,993 ft	07:53 UTC
DWX Dixon, WY	746 nm out, 17 nm southwest of the line	VFR Sky: a broken layer at 7,000 feet, a broken layer at 11,000 feet	from the south-southeast (150°) at 13 knots, gusting to 19	10+ mi	7,000 ft	6,548 ft	08:35 UTC
CFO Denver, CO	895 nm out, 3 nm east of the line, tower	VFR	from the south-southwest (200°) at 18 knots	10+ mi	none	5,515 ft	08:35 UTC
MEJ Meade, KS	1144 nm out, 6 nm northeast of the line	no report just now				2,527 ft
OUN Norman, OK	1333 nm out, 5 nm north of the line, tower	VFR	from the south (170°) at 10 knots	10+ mi	none	1,181 ft	08:35 UTC
ADM Ardmore, OK	1383 nm out, 23 nm southwest of the line, tower	reported, no category	calm		none	776 ft	08:15 UTC
SHV Shreveport, LA	1582 nm out, 5 nm north of the line, tower	VFR	from the south-southwest (200°) at 7 knots	10+ mi	none	257 ft	07:56 UTC
AEX Alexandria, LA	destination	VFR	calm	10+ mi	none	88 ft	2:53 am CDT (07:53 UTC)

The highest airport on this list sits at 6,993 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At AEX when you get there the forecast at the estimated arrival, 3:21 pm CDT (20:21 UTC)

Wind from the south-southeast at 7 knots, visibility more than 6 miles, clear skies VFR

The whole forecast for AEX

From Mon 1:00 am CDT (06:00 UTC): wind light and variable, visibility more than 6 miles, clear skies
From Mon 10:00 am CDT (15:00 UTC): wind from the south-southeast at 7 knots, visibility more than 6 miles, clear skies
From Mon 9:00 pm CDT (02:00 UTC): wind from the south at 4 knots, visibility more than 6 miles, clear skies

The forecast for BFI, the departure

From Sun 11:00 pm PDT (06:00 UTC): wind calm, visibility more than 6 miles, clear skies
From Mon 3:00 am PDT (10:00 UTC): wind calm, 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
From Mon 7:00 pm PDT (02:00 UTC): wind calm, visibility more than 6 miles, clear skies

Temporary flight restrictions on the line or within 25 nm of it

6/8911 DENVER, CO, Monday, October 12, 2026 UTC 1 nm from the route, 876 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · today · ZDV

Daylight

Sunset at BFI 6:25 pm PDT (01:25 UTC), at AEX 6:42 pm CDT (23:42 UTC) (civil twilight ends 7:06 pm CDT (00:06 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 now, the northern Rockies · loop National Weather Service

Radar now, the southern Rockies · 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: Boeing Fld/King County International, Alexandria International.