Great Falls International to George Bush Intcntl/Houston Airport GTF → IAH
1,286 nautical miles (1,480 statute miles) southeast on a straight line, true course 139°, about 126° magnetic at the departure end (variation 13E). At 120 knots that is 9 h 27 min at the quickest height in today's winds (39,000 ft, a 16-knot tailwind), arriving about 1:07 pm CDT (18:07 UTC). Right now GTF is low IFR, wind from the north-northwest (340°) at 7 knots; IAH 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: 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 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the first 299 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the first 120 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 289 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 120 to 279 nm out.
- AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the route from 259 to 588 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 279 to 478 nm out.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 42,000 ft. Over the route from 289 to 548 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 668 to 997 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 GTF.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- B737 at 18,000 ft, 47 nm southwest, 1:24 am MDT (07:24 UTC): moderate turbulence, remarks: FL180-130. 488 nm along the route, 47 nm southwest 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
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 12 forecast points nearest it (GTF, BIL, LND, BFF, DEN, GLD, GCK, GAG, SPS, DAL, CLL, HOU). 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 | 240° at 21 kt | −1 kt | 22 °C | 121 kt | 10 h 38 min | 2:18 pm CDT (19:18 UTC) |
| 7,500 ft | 240° at 20 kt | −3 kt | 14 °C | 123 kt | 10 h 27 min | 2:07 pm CDT (19:07 UTC) |
| 9,500 ft | 250° at 20 kt | −4 kt | 8 °C | 124 kt | 10 h 22 min | 2:02 pm CDT (19:02 UTC) |
| 11,500 ft | 240° at 20 kt | −3 kt | 5 °C | 123 kt | 10 h 27 min | 2:07 pm CDT (19:07 UTC) |
| 13,500 ft | 240° at 23 kt | −1 kt | 1 °C | 121 kt | 10 h 38 min | 2:18 pm CDT (19:18 UTC) |
| 15,500 ft | 230° at 26 kt | +1 kt | -3 °C | 119 kt | 10 h 48 min | 2:28 pm CDT (19:28 UTC) |
| 17,500 ft | 230° at 30 kt | +3 kt | -8 °C | 117 kt | 10 h 59 min | 2:39 pm CDT (19:39 UTC) |
| 18,000 ft FL180 | 230° at 31 kt | +3 kt | -9 °C | 117 kt | 10 h 59 min | 2:39 pm CDT (19:39 UTC) |
| 24,000 ft FL240 | 230° at 39 kt | +3 kt | -20 °C | 117 kt | 10 h 59 min | 2:39 pm CDT (19:39 UTC) |
| 30,000 ft FL300 | 240° at 51 kt | −6 kt | -31 °C | 126 kt | 10 h 12 min | 1:52 pm CDT (18:52 UTC) |
| 34,000 ft FL340 | 250° at 51 kt | −12 kt | -37 °C | 132 kt | 9 h 45 min | 1:25 pm CDT (18:25 UTC) |
| 39,000 ft FL390 | 250° at 48 kt | −16 kt | -48 °C | 136 kt | 9 h 27 min | 1:07 pm CDT (18:07 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| GTF | used from 0 nm out; 25 nm from the line | L/V | L/V -7° | 240/8 -8° | 240/30 -14° | 240/40 -28° | 210/52 -38° | 210/76 -38° | 220/72 -43° | |
| BIL | used from 100 nm out; 37 nm from the line | 300/14 | 270/19 -2° | 260/26 -2° | 220/28 -13° | 210/51 -25° | 220/56 -33° | 220/61 -39° | 220/72 -45° | |
| LND | used from 249 nm out; 95 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° | ||
| BFF | used from 349 nm out; 109 nm from the line | 280/28 | 260/39 11° | 240/34 5° | 210/38 -11° | 210/52 -22° | 230/61 -31° | 230/61 -36° | 240/56 -45° | |
| DEN | used from 498 nm out; 59 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° | ||
| GLD | used from 598 nm out; 43 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 698 nm out; 32 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 797 nm out; 27 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° | |
| SPS | used from 897 nm out; 76 nm from the line | 220/35 | 220/31 18° | 230/16 14° | 230/10 8° | 250/18 -5° | 250/32 -16° | 260/51 -28° | 280/46 -38° | 300/50 -50° |
| DAL | used from 1046 nm out; 35 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° |
| CLL | used from 1146 nm out; 62 nm from the line | 180/24 | 170/21 19° | 180/10 14° | 230/7 8° | 230/16 -6° | 260/20 -13° | 290/23 -29° | 320/21 -39° | 340/35 -51° |
| HOU | used from 1246 nm out; 40 nm from the line | 180/22 | 180/20 16° | 170/7 15° | L/V 8° | 220/11 -6° | 260/15 -13° | 310/20 -30° | 320/20 -40° | 350/32 -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 |
|---|---|---|---|---|---|---|---|
| GTF Great Falls, MT | departure | low IFR Sky: a broken layer at 400 feet, overcast at 1,200 feet Weather: light snow, mist | from the north-northwest (340°) at 7 knots | 2.5 mi | 400 ft | 3,680 ft | 2:34 am MDT (08:34 UTC) |
| HWQ Harlowton, MT | 90 nm out, 7 nm northeast of the line | no report just now | 4,311 ft | ||||
| GEY Greybull, WY | 229 nm out, 10 nm west of the line | marginal VFR Sky: overcast at 1,200 feet | from the west-northwest (300°) at 14 knots | 10+ mi | 1,200 ft | 3,941 ft | 07:53 UTC |
| CPR Casper, WY | 349 nm out, 13 nm west of the line, tower | VFR Sky: a few clouds at 7,500 feet | from the southwest (230°) at 20 knots, gusting to 28 | 10+ mi | none | 5,344 ft | 08:23 UTC |
| CYS Cheyenne, WY | 468 nm out, 17 nm southwest of the line, tower | VFR | from the west (270°) at 20 knots, gusting to 37 | 10+ mi | none | 6,159 ft | 07:53 UTC |
| AKO Akron, CO | 558 nm out, 9 nm east of the line | VFR | from the west (270°) at 14 knots, gusting to 24 | 10+ mi | none | 4,716 ft | 07:53 UTC |
| ULS Ulysses, KS | 738 nm out, 9 nm southwest of the line | VFR | from the south (190°) at 18 knots, gusting to 29 | 10+ mi | none | 3,071 ft | 08:35 UTC |
| ELK Elk City, OK | 897 nm out, 3 nm south of the line | VFR | from the south-southwest (200°) at 15 knots | 10+ mi | none | 2,012 ft | 08:35 UTC |
| CSM Burns Flat, OK | 907 nm out, 4 nm east of the line, tower | VFR | from the south (190°) at 18 knots | 10+ mi | none | 1,922 ft | 07:53 UTC |
| FTW Fort Worth, TX | 1086 nm out, 0 nm southwest of the line, tower | VFR | from the south (170°) at 13 knots | 10+ mi | none | 710 ft | 07:53 UTC |
| CXO Houston, TX | 1266 nm out, 8 nm northeast of the line, tower | VFR | calm | 10+ mi | none | 244 ft | 07:53 UTC |
| IAH Houston, TX | destination | VFR Sky: a few clouds at 3,500 feet, overcast at 23,000 feet | calm | 10+ mi | 23,000 ft | 95 ft | 2:53 am CDT (07:53 UTC) |
The highest airport on this list sits at 6,159 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At IAH when you get there the forecast at the estimated arrival, 1:07 pm CDT (18:07 UTC)
Wind from the southeast at 11 knots, visibility more than 6 miles, scattered clouds at 3,500 feet, a broken layer at 25,000 feet VFR
30% chance between Mon 1:00 pm CDT (18:00 UTC) and 5:00 pm CDT (22:00 UTC): light rain showers
The whole forecast for IAH
- From Mon 1:00 am CDT (06:00 UTC): wind from the south-southeast at 7 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
- From Mon 4:00 am CDT (09:00 UTC): wind from the east-southeast at 4 knots, visibility more than 6 miles, scattered clouds at 2,500 feet, scattered clouds at 25,000 feet
- From Mon 12:00 pm CDT (17:00 UTC): wind from the southeast at 11 knots, visibility more than 6 miles, scattered clouds at 3,500 feet, a broken layer at 25,000 feet
- 30% chance between Mon 1:00 pm CDT (18:00 UTC) and 5:00 pm CDT (22:00 UTC): light rain showers
The forecast for GTF, the departure
- From Mon 12:00 am MDT (06:00 UTC): wind from the north-northeast at 12 knots, visibility 3 miles, light snow, overcast at 600 feet
- At times between Mon 12:00 am MDT (06:00 UTC) and 3:00 am MDT (09:00 UTC): visibility 2 miles, light snow
- From Mon 3:00 am MDT (09:00 UTC): wind from the north at 9 knots, visibility more than 6 miles, overcast at 600 feet
- At times between Mon 3:00 am MDT (09:00 UTC) and 5:00 am MDT (11:00 UTC): visibility 2 miles, light snow, overcast at 300 feet
- From Mon 12:00 pm MDT (18:00 UTC): wind light and variable, visibility more than 6 miles, overcast at 1,000 feet
- From Mon 9:00 pm MDT (03:00 UTC): wind light and variable, visibility 6 miles, mist, scattered clouds at 1,000 feet
Temporary flight restrictions on the line or within 25 nm of it
- 9/2934 DALLAS, TX 25 nm from the route, 1096 nm along the route · a VIP movement · ZFW
- 6/8646 Arlington, TX, Thursday, October 15, 2026 through Friday, October 16, 2026 UTC 8 nm from the route, 1096 nm along the route · drones kept away from a public gathering · starts Thursday 15 October · ZFW
Daylight
Sunset at GTF 6:41 pm MDT (00:41 UTC), at IAH 6:54 pm CDT (23:54 UTC) (civil twilight ends 7:18 pm CDT (00:18 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: Great Falls International, George Bush Intcntl/Houston Airport.