Great Falls International to Friedman Memorial GTF → SUN
269 nautical miles (309 statute miles) southwest on a straight line, true course 208°, about 195° magnetic at the departure end (variation 13E). At 120 knots that is 2 h 24 min at the quickest height in today's winds (8,500 ft, a 8-knot headwind), arriving about 7:53 am MDT (13:53 UTC). Right now GTF is low IFR, wind from the northwest (320°) at 6 knots; SUN is marginal VFR, wind from the south-southeast (160°) at 4 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: 3 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 whole route.
- AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the first 169 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the last 259 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the last 90 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 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 3 forecast points nearest it (GTF, DLN, PIH). 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 | 180° at 8 kt | +8 kt | -4 °C | 112 kt | 2 h 24 min | 7:53 am MDT (13:53 UTC) |
| 10,500 ft | 210° at 14 kt | +14 kt | -5 °C | 106 kt | 2 h 32 min | 8:01 am MDT (14:01 UTC) |
| 12,500 ft | 220° at 21 kt | +20 kt | -6 °C | 100 kt | 2 h 41 min | 8:10 am MDT (14:10 UTC) |
| 14,500 ft | 220° at 22 kt | +21 kt | -10 °C | 99 kt | 2 h 43 min | 8:12 am MDT (14:12 UTC) |
| 16,500 ft | 220° at 23 kt | +23 kt | -14 °C | 97 kt | 2 h 46 min | 8:15 am MDT (14:15 UTC) |
| 18,000 ft FL180 | 220° at 24 kt | +24 kt | -17 °C | 96 kt | 2 h 48 min | 8:17 am MDT (14:17 UTC) |
| 24,000 ft FL240 | 220° at 41 kt | +41 kt | -28 °C | 79 kt | 3 h 24 min | 8:53 am MDT (14:53 UTC) |
| 30,000 ft FL300 | 210° at 60 kt | +59 kt | -34 °C | 61 kt | 4 h 25 min | 9:54 am MDT (15:54 UTC) |
| 34,000 ft FL340 | 210° at 72 kt | +72 kt | -37 °C | 48 kt | 5 h 36 min | 11:05 am MDT (17:05 UTC) |
| 39,000 ft FL390 | 210° at 67 kt | +67 kt | -44 °C | 53 kt | 5 h 05 min | 10:34 am MDT (16:34 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° | |
| DLN | used from 50 nm out; 69 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 249 nm out; 83 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° |
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: 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) |
| HLN Helena, MT | 60 nm out, 3 nm east of the line, tower | marginal VFR Sky: a broken layer at 2,300 feet, a broken layer at 2,900 feet, overcast at 4,400 feet | from the west (270°) at 8 knots | 10+ mi | 2,300 ft | 3,877 ft | 10:53 UTC |
| BTM Butte, MT | 100 nm out, 4 nm south of the line | IFR Sky: a broken layer at 600 feet, overcast at 2,000 feet | calm | 8 mi | 600 ft | 5,550 ft | 10:53 UTC |
| DLN Dillon, MT | 139 nm out, 19 nm southeast of the line | IFR Sky: a broken layer at 600 feet, overcast at 1,700 feet | from the north-northeast (020°) at 3 knots | 10+ mi | 600 ft | 5,244 ft | 11:12 UTC |
| LLJ Challis, ID | 209 nm out, 24 nm west of the line | marginal VFR Sky: overcast at 2,700 feet | from the north-northwest (330°) at 6 knots | 10+ mi | 2,700 ft | 5,075 ft | 10:55 UTC |
| SUN Hailey, ID | destination | marginal VFR Sky: scattered clouds at 600 feet, a broken layer at 2,700 feet, overcast at 3,100 feet Weather: light rain | from the south-southeast (160°) at 4 knots | 10+ mi | 2,700 ft | 5,319 ft | 5:15 am MDT (11:15 UTC) |
The highest airport on this list sits at 5,550 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At SUN when you get there the forecast at the estimated arrival, 7:53 am MDT (13:53 UTC)
Wind light and variable, visibility 6 miles, light rain showers, scattered clouds at 700 feet, overcast at 2,000 feet marginal VFR
The whole forecast for SUN
- From Mon 6:00 am MDT (12:00 UTC): wind light and variable, visibility 6 miles, light rain showers, scattered clouds at 700 feet, overcast at 2,000 feet
- From Mon 1:00 pm MDT (19:00 UTC): wind from the south-southeast at 6 knots, visibility more than 6 miles, showers nearby, a few clouds at 1,200 feet, scattered clouds at 2,500 feet and more above
- From Mon 10:00 pm MDT (04:00 UTC): wind from the west-northwest at 7 knots, visibility more than 6 miles, showers nearby, scattered clouds at 3,000 feet, a broken layer at 5,000 feet and more above
The forecast for GTF, the departure
- 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
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 SUN 6:57 pm MDT (00:57 UTC) (civil twilight ends 7:26 pm MDT (01:26 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, Friedman Memorial.