Great Falls International to Denver International GTF → DEN
542 nautical miles (623 statute miles) southeast on a straight line, true course 145°, about 132° magnetic at the departure end (variation 13E). At 120 knots that is 4 h 12 min at the quickest height in today's winds (5,500 ft, a 9-knot tailwind), arriving about 12:10 pm MDT (18:10 UTC). 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: 1,456 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 335 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the first 138 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 355 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 148 to 276 nm out.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft (due to mountain wave) from 34,000 ft to 43,000 ft. Over the last 197 nm of the route.
- AIRMET TANGO 2W: moderate turbulence below 18,000 ft (due to mountain wave) up to 22,000 ft. Over the last 158 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 GTF.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
Not fetched just now.
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 5 forecast points nearest it (GTF, BIL, LND, BFF, 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 |
|---|---|---|---|---|---|---|
| 5,500 ft | 290° at 11 kt | −9 kt | 129 kt | 4 h 12 min | 12:10 pm MDT (18:10 UTC) | |
| 7,500 ft | 270° at 14 kt | −7 kt | 6 °C | 127 kt | 4 h 16 min | 12:14 pm MDT (18:14 UTC) |
| 9,500 ft | 260° at 16 kt | −6 kt | 1 °C | 126 kt | 4 h 18 min | 12:16 pm MDT (18:16 UTC) |
| 11,500 ft | 250° at 21 kt | −4 kt | 0 °C | 124 kt | 4 h 22 min | 12:20 pm MDT (18:20 UTC) |
| 13,500 ft | 240° at 25 kt | 0 | -4 °C | 120 kt | 4 h 31 min | 12:29 pm MDT (18:29 UTC) |
| 15,500 ft | 230° at 30 kt | +4 kt | -7 °C | 116 kt | 4 h 40 min | 12:38 pm MDT (18:38 UTC) |
| 17,500 ft | 230° at 35 kt | +7 kt | -11 °C | 113 kt | 4 h 48 min | 12:46 pm MDT (18:46 UTC) |
| 18,000 ft FL180 | 220° at 36 kt | +8 kt | -12 °C | 112 kt | 4 h 50 min | 12:48 pm MDT (18:48 UTC) |
| 24,000 ft FL240 | 220° at 47 kt | +11 kt | -24 °C | 109 kt | 4 h 58 min | 12:56 pm MDT (18:56 UTC) |
| 30,000 ft FL300 | 220° at 56 kt | +16 kt | -33 °C | 104 kt | 5 h 13 min | 1:11 pm MDT (19:11 UTC) |
| 34,000 ft FL340 | 220° at 63 kt | +16 kt | -37 °C | 104 kt | 5 h 13 min | 1:11 pm MDT (19:11 UTC) |
| 39,000 ft FL390 | 230° at 66 kt | +13 kt | -45 °C | 107 kt | 5 h 04 min | 1:02 pm MDT (19:02 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 98 nm out; 48 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 246 nm out; 68 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 394 nm out; 111 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 443 nm out; 74 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 |
|---|---|---|---|---|---|---|---|
| GTF Great Falls, MT | departure | no report just now | 3,680 ft | ||||
| HWQ Harlowton, MT | 89 nm out, 17 nm northeast of the line | no report just now | 4,311 ft | ||||
| POY Powell, WY | 187 nm out, 3 nm southeast of the line | no report just now | 5,096 ft | ||||
| WRL Worland, WY | 256 nm out, 3 nm northeast of the line | no report just now | 4,251 ft | ||||
| CPR Casper, WY | 345 nm out, 24 nm northeast of the line, tower | no report just now | 5,344 ft | ||||
| LAR Laramie, WY | 443 nm out, 5 nm northeast of the line | no report just now | 7,283 ft | ||||
| FNL Fort Collins/Loveland, CO | 502 nm out, 5 nm east of the line, tower | no report just now | 5,020 ft | ||||
| DEN Denver, CO | destination | no report just now | 5,433 ft |
The highest airport on this list sits at 7,283 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At DEN when you get there the forecast at the estimated arrival, 12:10 pm MDT (18:10 UTC)
DEN has no terminal forecast; use the nearest airport that does.
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 GTF 6:41 pm MDT (00:41 UTC), at DEN 6:22 pm MDT (00:22 UTC) (civil twilight ends 6:49 pm MDT (00:49 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, Denver International.