Plan a flight · Mon 4:40 am EDT (08:40 UTC)

Washington Dulles International to Vance Brand Airport IAD → LMO

1,279 nautical miles (1,472 statute miles) west on a straight line, true course 282°, about 292° magnetic at the departure end (variation 10W). At 120 knots that is 12 h 32 min at the quickest height in today's winds (8,500 ft, a 18-knot headwind), arriving about 3:12 pm MDT (21:12 UTC). Right now IAD is marginal VFR, wind from the northwest (320°) at 11 knots, gusting to 20; LMO is VFR, wind from the southwest (230°) at 5 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 SIERRA 3E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist, fog). Over the first 390 nm of the route.
AIRMET TANGO 5W: moderate turbulence below 18,000 ft (due to mountain wave) up to 10,000 ft. Over the first 70 nm of the route.
AIRMET SIERRA 4E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 30 to 180 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 630 to 1119 nm out.
AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the last 80 nm of the route.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 42,000 ft. Over the last 70 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 last 20 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 IAD.

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

B737 at 18,000 ft, 25 nm north, 3:24 am EDT (07:24 UTC): moderate turbulence, remarks: FL180-130. At the destination end, 25 nm north 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
B737 at 800 ft, 39 nm east, 3:30 am EDT (07:30 UTC): remarks: bases 800 ft. At the departure end, 39 nm east of the line.
as filed, and in English
```
BWI UA /OV BWI/TM 0730/FL008/TP B737/RM BASES 008
```
Report
a routine report filed through BWI
Where
over BWI
Time
07:30 UTC
Height
at 800 ft
Aircraft
B737
Remarks
bases 800 ft
B739 at 35,000 ft, 45 nm north, 3:05 am EDT (07:05 UTC): no turbulence. 500 nm along the route, 45 nm north of the line.
as filed, and in English
```
TIP UA /OV RBS010023/TM 0705/FL350/TP B739/TB NEG
```
Report
a routine report filed through TIP
Where
23 nm north (010°) of RBS
Time
07:05 UTC
Height
at 35,000 ft
Aircraft
B739
Turbulence
none
B737 descending, 23 nm south, 4:10 am EDT (08:10 UTC): light chop turbulence. At the destination end, 23 nm south 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, 23 nm south, 3:10 am EDT (07:10 UTC): remarks: smooth. At the destination end, 23 nm south 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, 23 nm south, 2:15 am EDT (06:15 UTC): light chop turbulence. At the destination end, 23 nm south 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
A20N at 25,000 ft, 37 nm southwest, 2:19 am EDT (06:19 UTC): light chop turbulence up to 26,000 ft, remarks: during the climb ZDVWC-06. At the destination end, 37 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

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 12 forecast points nearest it (EKN, CRW, CMH, CVG, IND, SPI, BRL, DSM, OMA, GRI, GLD, DEN). 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	260° at 24 kt	+24 kt	16 °C	96 kt	13 h 19 min	3:59 pm MDT (21:59 UTC)
6,500 ft	270° at 20 kt	+21 kt	16 °C	99 kt	12 h 55 min	3:35 pm MDT (21:35 UTC)
8,500 ft	270° at 17 kt	+18 kt	11 °C	102 kt	12 h 32 min	3:12 pm MDT (21:12 UTC)
10,500 ft	270° at 17 kt	+18 kt	8 °C	102 kt	12 h 32 min	3:12 pm MDT (21:12 UTC)
12,500 ft	270° at 18 kt	+19 kt	4 °C	101 kt	12 h 40 min	3:20 pm MDT (21:20 UTC)
14,500 ft	270° at 20 kt	+22 kt	0 °C	98 kt	13 h 03 min	3:43 pm MDT (21:43 UTC)
16,500 ft	270° at 23 kt	+24 kt	-5 °C	96 kt	13 h 19 min	3:59 pm MDT (21:59 UTC)
18,000 ft FL180	270° at 25 kt	+26 kt	-8 °C	94 kt	13 h 36 min	4:16 pm MDT (22:16 UTC)
24,000 ft FL240	270° at 31 kt	+33 kt	-20 °C	87 kt	14 h 42 min	5:22 pm MDT (23:22 UTC)
30,000 ft FL300	280° at 41 kt	+43 kt	-33 °C	77 kt	16 h 37 min	7:17 pm MDT (01:17 UTC)
34,000 ft FL340	280° at 54 kt	+56 kt	-39 °C	64 kt	19 h 59 min	10:39 pm MDT (04:39 UTC)
39,000 ft FL390	280° at 53 kt	+54 kt	-49 °C	66 kt	19 h 23 min	10:03 pm MDT (04:03 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
EKN	used from 0 nm out; 88 nm from the line		330/20 10°	350/29 7°	340/32 2°	340/44 -8°	350/50 -21°	350/63 -35°	340/69 -40°	330/42 -50°
CRW	used from 150 nm out; 71 nm from the line	320/17	340/23 12°	340/32 8°	340/35 4°	330/40 -7°	340/45 -20°	340/57 -34°	340/64 -42°	320/38 -50°
CMH	used from 200 nm out; 38 nm from the line	320/12	340/26 15°	340/22 9°	320/24 3°	320/32 -7°	320/36 -20°	330/42 -35°	320/59 -44°	320/57 -50°
CVG	used from 300 nm out; 52 nm from the line	300/19	310/23 15°	320/20 9°	310/18 3°	300/26 -6°	290/36 -19°	310/32 -34°	310/53 -43°	310/61 -51°
IND	used from 350 nm out; 43 nm from the line	270/22	290/19 15°	270/19 8°	270/18 4°	290/28 -7°	280/35 -20°	270/37 -34°	300/51 -42°	300/61 -51°
SPI	used from 500 nm out; 52 nm from the line	260/28	250/22 15°	250/14 9°	260/20 6°	280/27 -7°	280/34 -19°	280/48 -32°	280/59 -41°	300/60 -49°
BRL	used from 600 nm out; 27 nm from the line	250/32	250/19 17°	260/15 11°	270/16 3°	290/23 -7°	260/42 -20°	270/52 -34°	280/63 -39°	290/64 -48°
DSM	used from 700 nm out; 71 nm from the line	250/47	260/25 20°	240/19 11°	240/31 5°	250/26 -9°	260/38 -20°	260/47 -34°	270/58 -37°	270/61 -47°
OMA	used from 800 nm out; 57 nm from the line	230/47	240/33 21°	230/22 13°	220/27 5°	240/35 -8°	250/43 -21°	260/47 -33°	260/59 -36°	270/58 -46°
GRI	used from 900 nm out; 49 nm from the line		230/39 23°	230/32 15°	210/29 7°	230/31 -8°	230/43 -21°	250/52 -31°	260/59 -35°	260/59 -46°
GLD	used from 1049 nm out; 78 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°
DEN	used from 1199 nm out; 40 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°

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
IAD Washington, DC	departure	marginal VFR Sky: scattered clouds at 1,000 feet, a broken layer at 1,500 feet, overcast at 3,000 feet Weather: light rain, mist	from the northwest (320°) at 11 knots, gusting to 20	4 mi	1,500 ft	312 ft	3:52 am EDT (07:52 UTC)
MGW Morgantown, WV	120 nm out, 19 nm north of the line, tower	low IFR Sky: overcast at 300 feet Weather: mist	from the northwest (310°) at 3 knots	2.5 mi	300 ft	1,243 ft	08:07 UTC
CKB Clarksburg, WV	130 nm out, 5 nm south of the line, tower	marginal VFR Sky: a few clouds at 700 feet, a broken layer at 1,400 feet, overcast at 1,900 feet Weather: light rain	from the west-northwest (300°) at 5 knots	9 mi	1,400 ft	1,223 ft	08:09 UTC
DAY Dayton, OH	320 nm out, 2 nm northeast of the line, tower	low IFR Sky: overcast at 400 feet	from the west-northwest (300°) at 5 knots	8 mi	400 ft	1,009 ft	07:56 UTC
CMI Champaign/Urbana, IL	510 nm out, 12 nm south of the line, tower	VFR	from the south (180°) at 6 knots	10+ mi	none	754 ft	07:53 UTC
BMI Bloomington/Normal, IL	540 nm out, 13 nm north of the line, tower	VFR	from the south-southwest (200°) at 7 knots	10+ mi	none	871 ft	07:56 UTC
EOK Keokuk, IA	650 nm out, 4 nm north of the line	reported, no category	from the south-southwest (210°) at 5 knots	10+ mi	none	671 ft	08:15 UTC
LNK Lincoln, NE	890 nm out, 21 nm north of the line, tower	VFR	from the south (190°) at 12 knots	10+ mi	none	1,218 ft	07:54 UTC
HDE Holdrege, NE	1009 nm out, 3 nm west of the line	VFR	from the south (170°) at 9 knots	10+ mi	none	2,313 ft	08:15 UTC
CSB Cambridge, NE	1049 nm out, 8 nm south of the line	VFR	variable at 6 knots	10+ mi	none	2,414 ft	08:15 UTC
DEN Denver, CO	1259 nm out, 20 nm south of the line, tower	VFR	from the south-southwest (200°) at 20 knots	10+ mi	none	5,433 ft	07:53 UTC
LMO Longmont, CO	destination	VFR	from the southwest (230°) at 5 knots	7 mi	none	5,055 ft	2:15 am MDT (08:15 UTC)

The highest airport on this list sits at 5,433 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At LMO when you get there the forecast at the estimated arrival, 3:12 pm MDT (21:12 UTC)

LMO has no terminal forecast; use the nearest airport that does.

The forecast for IAD, the departure

From Mon 2:00 am EDT (06:00 UTC): wind from the north-northwest at 12 knots, visibility 5 miles, light rain, mist, overcast at 600 feet
From Mon 8:00 am EDT (12:00 UTC): wind from the north-northwest at 10 knots, gusting to 18, visibility more than 6 miles, overcast at 1,000 feet
From Mon 12:00 pm EDT (16:00 UTC): wind from the north-northwest at 13 knots, gusting to 21, visibility more than 6 miles, scattered clouds at 1,500 feet, overcast at 2,500 feet
From Mon 2:00 pm EDT (18:00 UTC): wind from the north-northwest at 11 knots, gusting to 18, visibility more than 6 miles, scattered clouds at 2,500 feet, overcast at 3,500 feet
From Mon 5:00 pm EDT (21:00 UTC): wind from the northwest at 7 knots, visibility more than 6 miles, a broken layer at 3,500 feet
From Mon 8:00 pm EDT (00:00 UTC): wind from the west-northwest at 3 knots, visibility more than 6 miles, scattered clouds at 4,000 feet

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

4/9383 WASHINGTON, DC., USA 8 nm from the route, at the departure end · security · ZDC
6/8600 Sterling, VA, Monday, October 12, 2026 through Monday, October 12, 2026 Local 4 nm from the route, at the departure end · a VIP movement · today · ZDC
6/8911 DENVER, CO, Monday, October 12, 2026 UTC 12 nm from the route, at the destination end · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · today · ZDV

Daylight

Sunset at IAD 6:36 pm EDT (22:36 UTC), at LMO 6:24 pm MDT (00:24 UTC) (civil twilight ends 6:51 pm MDT (00:51 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 Northeast · loop National Weather Service

Radar now, the central Great Lakes · loop National Weather Service

Radar now, the upper Mississippi valley · 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: Washington Dulles International, Vance Brand Airport.