City Of Colorado Springs Municipal to Great Falls International COS → GTF
597 nautical miles (687 statute miles) northwest on a straight line, true course 333°, about 325° magnetic at the departure end (variation 8E). At 120 knots that is 4 h 18 min at the quickest height in today's winds (30,000 ft, a 19-knot tailwind), arriving about 9:41 am MDT (15:41 UTC). Right now COS is VFR, wind from the southwest (230°) at 11 knots, gusting to 22; GTF is low IFR, wind from the northwest (320°) 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: 5 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: 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 first 20 nm of the route.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft (due to mountain wave) from 34,000 ft to 43,000 ft. Over the first 259 nm of the route.
- AIRMET TANGO 2W: moderate turbulence below 18,000 ft (due to mountain wave) up to 22,000 ft. Over the first 229 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 119 to 587 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 129 to 249 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 189 to 249 nm out.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 269 to 448 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 last 269 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the last 139 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 COS.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- B763 at 23,000 ft, 3 nm east, 4:26 am MDT (10:26 UTC): light chop turbulence, remarks: zdvwc. 80 nm along the route, 3 nm east of the line.
as filed, and in English
DEN UA /OV DEN278037/TM 1026/FL230/TP B763/TB OCNL LGT CHOP/RM ZDVWC
- Report
- a routine report filed through DEN
- Where
- 37 nm west (278°) of DEN
- Time
- 10:26 UTC
- Height
- at 23,000 ft
- Aircraft
- B763
- Turbulence
- occasional light chop
- Remarks
- zdvwc
- BE9L at 17,000 ft, 32 nm northeast, 3:42 am MDT (09:42 UTC): light rime icing from 15,000 ft to 17,000 ft, 0 °C, remarks: zdvwc. 269 nm along the route, 32 nm northeast of the line.
as filed, and in English
CPR UA /OV DDY250025/TM 0942/FL170/TP BE9L/TA 00/IC LGT RIME 150-170/RM ZDVWC
- Report
- a routine report filed through CPR
- Where
- 25 nm west (250°) of DDY
- Time
- 09:42 UTC
- Height
- at 17,000 ft
- Aircraft
- BE9L
- Temperature
- 0 °C
- Icing
- light rime from 15,000 ft to 17,000 ft
- Remarks
- 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 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 5 forecast points nearest it (DEN, RKS, LND, BIL, GTF). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 8,500 ft | 260° at 13 kt | +4 kt | 6 °C | 116 kt | 5 h 09 min | 10:32 am MDT (16:32 UTC) |
| 10,500 ft | 250° at 16 kt | +2 kt | 1 °C | 118 kt | 5 h 04 min | 10:27 am MDT (16:27 UTC) |
| 12,500 ft | 240° at 22 kt | −1 kt | -1 °C | 121 kt | 4 h 56 min | 10:19 am MDT (16:19 UTC) |
| 14,500 ft | 230° at 28 kt | −4 kt | -5 °C | 124 kt | 4 h 49 min | 10:12 am MDT (16:12 UTC) |
| 16,500 ft | 230° at 34 kt | −8 kt | -9 °C | 128 kt | 4 h 40 min | 10:03 am MDT (16:03 UTC) |
| 18,000 ft FL180 | 220° at 39 kt | −11 kt | -12 °C | 131 kt | 4 h 33 min | 9:56 am MDT (15:56 UTC) |
| 24,000 ft FL240 | 230° at 48 kt | −12 kt | -23 °C | 132 kt | 4 h 31 min | 9:54 am MDT (15:54 UTC) |
| 30,000 ft FL300 | 220° at 56 kt | −19 kt | -33 °C | 139 kt | 4 h 18 min | 9:41 am MDT (15:41 UTC) |
| 34,000 ft FL340 | 220° at 63 kt | −18 kt | -37 °C | 138 kt | 4 h 20 min | 9:43 am MDT (15:43 UTC) |
| 39,000 ft FL390 | 230° at 64 kt | −17 kt | -45 °C | 137 kt | 4 h 21 min | 9:44 am MDT (15:44 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| DEN | used from 0 nm out; 43 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° | ||
| RKS | used from 149 nm out; 118 nm from the line | 250/9 | 230/21 -1° | 210/43 -14° | 220/59 -23° | 220/55 -32° | 220/53 -35° | 220/48 -44° | ||
| LND | used from 199 nm out; 88 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° | ||
| BIL | used from 398 nm out; 57 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° | |
| GTF | used from 497 nm out; 75 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° |
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 |
|---|---|---|---|---|---|---|---|
| COS Colorado Springs, CO | departure | VFR Sky: a few clouds at 20,000 feet | from the southwest (230°) at 11 knots, gusting to 22 | 10+ mi | none | 6,187 ft | 4:54 am MDT (10:54 UTC) |
| APA Denver, CO | 40 nm out, 15 nm northeast of the line, tower | VFR | from the south (170°) at 11 knots | 10+ mi | none | 5,884 ft | 10:53 UTC |
| BJC Denver, CO | 70 nm out, 13 nm east of the line, tower | VFR | from the west-northwest (300°) at 3 knots | 10+ mi | none | 5,673 ft | 11:15 UTC |
| SAA Saratoga, WY | 189 nm out, 13 nm southwest of the line | reported, no category | from the southeast (140°) at 7 knots, gusting to 26 | 10+ mi | none | 7,014 ft | 10:50 UTC |
| HSG Thermopolis, WY | 338 nm out, 7 nm southwest of the line | marginal VFR Sky: overcast at 2,500 feet | from the north-northeast (020°) at 8 knots | 10+ mi | 2,500 ft | 4,891 ft | 11:15 UTC |
| COD Cody, WY | 398 nm out, 8 nm southwest of the line | marginal VFR Sky: overcast at 1,600 feet | from the north (010°) at 9 knots | 10+ mi | 1,600 ft | 5,102 ft | 10:56 UTC |
| RED Red Lodge, MT | 438 nm out, 6 nm east of the line | no report just now | 5,762 ft | ||||
| HWQ Harlowton, MT | 507 nm out, 22 nm northeast of the line | no report just now | 4,311 ft | ||||
| GTF Great Falls, MT | destination | low IFR Sky: overcast at 400 feet Weather: mist | from the northwest (320°) at 6 knots | 1.75 mi | 400 ft | 3,680 ft | 5:18 am MDT (11:18 UTC) |
The highest airport on this list sits at 7,014 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At GTF when you get there the forecast at the estimated arrival, 9:41 am MDT (15:41 UTC)
Wind light and variable, visibility 6 miles, mist, overcast at 600 feet IFR
The whole forecast for GTF
- From Mon 6:00 am MDT (12:00 UTC): wind light and variable, visibility 6 miles, mist, overcast at 600 feet
- At times between Mon 6:00 am MDT (12:00 UTC) and 9:00 am MDT (15:00 UTC): visibility 2 miles, light snow, mist, overcast at 400 feet
- From Mon 10:00 am MDT (16:00 UTC): wind light and variable, visibility more than 6 miles, a broken layer at 700 feet
- From Mon 10:00 pm MDT (04:00 UTC): wind from the south-southwest at 6 knots, visibility more than 6 miles, scattered clouds at 500 feet
The forecast for COS, the departure
- From Mon 6:00 am MDT (12:00 UTC): wind from the southwest at 11 knots, gusting to 22, visibility more than 6 miles, a few clouds at 20,000 feet
- From Mon 11:00 am MDT (17:00 UTC): wind from the south at 15 knots, gusting to 25, visibility more than 6 miles, scattered clouds at 12,000 feet
- From Mon 1:00 pm MDT (19:00 UTC): wind from the south-southwest at 20 knots, gusting to 30, visibility more than 6 miles, scattered clouds at 12,000 feet
- From Mon 7:00 pm MDT (01:00 UTC): wind from the south-southwest at 12 knots, visibility more than 6 miles, clear skies
- From Mon 10:00 pm MDT (04:00 UTC): wind from the south-southeast at 6 knots, visibility more than 6 miles, scattered clouds at 25,000 feet
Temporary flight restrictions on the line or within 25 nm of it
- 6/8784 LAKE GEORGE, CO, Sunday, October 11, 2026 through Tuesday, October 13, 2026 UTC 23 nm from the route, at the departure end · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 13 October · ZDV
Daylight
Sunset at COS 6:23 pm MDT (00:23 UTC), at GTF 6:41 pm MDT (00:41 UTC) (civil twilight ends 7:12 pm MDT (01:12 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: City Of Colorado Springs Municipal, Great Falls International.