Helena Regional to Grand Junction Regional HLN → GJT
474 nautical miles (546 statute miles) south on a straight line, true course 160°, about 148° magnetic at the departure end (variation 12E). At 120 knots that is 4 h 28 min at the quickest height in today's winds (11,500 ft, a 14-knot headwind), arriving about 4:41 am MDT (10:41 UTC), after sunset at the destination. Right now HLN is VFR, wind from the west (270°) at 8 knots; GJT is VFR, wind variable 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: 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 168 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the first 99 nm of the route.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the first 59 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the whole route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 109 to 425 nm out.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 38,000 ft. Over the last 217 nm of the route.
- AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Over the last 208 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 99 nm of the route.
- AIRMET TANGO 5W: strong surface winds (30 knots or more) (due to sustained surface winds greater than 30 knots). Near the route, 376 nm along 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 HLN.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
- B737 , 16 nm northeast, 11:31 pm MDT (05:31 UTC): remarks: saw the light at 500FT braking good no icing. 59 nm along the route, 16 nm northeast of the line.
as filed, and in English
BZN UA /OV BZN/TM 0531/FLBURD/TP B737/RM SAW THE LIGHT AT 500FT. BRAKING GOOD. NEG ICING
- Report
- a routine report filed through BZN
- Where
- over BZN
- Time
- 05:31 UTC
- Height
- at BURD
- Aircraft
- B737
- Remarks
- saw the light at 500FT braking good no icing
- GLF5 descending, 16 nm northeast, 9:46 pm MDT (03:46 UTC): remarks: broke out 100-150FT above ground. 59 nm along the route, 16 nm northeast of the line.
as filed, and in English
BZN UA /OV BZN/TM 0346/FLDURD/TP GLF5/RM BROKE OUT 100-150FT AGL
- Report
- a routine report filed through BZN
- Where
- over BZN
- Time
- 03:46 UTC
- Height
- during the descent
- Aircraft
- GLF5
- Remarks
- broke out 100-150FT above ground
- BE20 at 16,000 ft, 43 nm east, 9:28 pm MDT (03:28 UTC): light chop turbulence, light rime icing, -3 °C, remarks: ZDVWC-11. At the destination end, 43 nm east of the line.
as filed, and in English
RIL UA /OV RIL/TM 0328/FL160/TP BE20/TA M03/TB LGT CHOP/IC LGT RIME/RM ZDVWC-11
- Report
- a routine report filed through RIL
- Where
- over RIL
- Time
- 03:28 UTC
- Height
- at 16,000 ft
- Aircraft
- BE20
- Temperature
- −3 °C
- Turbulence
- light chop
- Icing
- light rime
- Remarks
- ZDVWC-11
Winds aloft along the route, and the time en route the forecast for use 02:00–09:00 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 (DLN, PIH, LND, RKS, GJT). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 7,500 ft | 200° at 22 kt | +17 kt | 0 °C | 103 kt | 4 h 36 min | 4:49 am MDT (10:49 UTC) |
| 9,500 ft | 210° at 24 kt | +17 kt | -1 °C | 103 kt | 4 h 36 min | 4:49 am MDT (10:49 UTC) |
| 11,500 ft | 220° at 31 kt | +14 kt | -1 °C | 106 kt | 4 h 28 min | 4:41 am MDT (10:41 UTC) |
| 13,500 ft | 220° at 34 kt | +15 kt | -4 °C | 105 kt | 4 h 31 min | 4:44 am MDT (10:44 UTC) |
| 15,500 ft | 220° at 36 kt | +18 kt | -8 °C | 102 kt | 4 h 39 min | 4:52 am MDT (10:52 UTC) |
| 17,500 ft | 220° at 38 kt | +21 kt | -12 °C | 99 kt | 4 h 47 min | 5:00 am MDT (11:00 UTC) |
| 18,000 ft FL180 | 220° at 38 kt | +22 kt | -13 °C | 98 kt | 4 h 50 min | 5:03 am MDT (11:03 UTC) |
| 24,000 ft FL240 | 210° at 55 kt | +33 kt | -24 °C | 87 kt | 5 h 27 min | 5:40 am MDT (11:40 UTC) |
| 30,000 ft FL300 | 210° at 60 kt | +36 kt | -30 °C | 84 kt | 5 h 39 min | 5:52 am MDT (11:52 UTC) |
| 34,000 ft FL340 | 220° at 69 kt | +38 kt | -35 °C | 82 kt | 5 h 47 min | 6:00 am MDT (12:00 UTC) |
| 39,000 ft FL390 | 220° at 66 kt | +30 kt | -44 °C | 90 kt | 5 h 16 min | 5:29 am MDT (11:29 UTC) |
Based on data from the 12th at 00:00 UTC; valid on the 12th at 06:00 UTC for use 02:00 to 09:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| DLN | used from 0 nm out; 66 nm from the line | 090/6 -6° | 240/22 -4° | 210/34 -16° | 210/62 -25° | 210/66 -34° | 210/82 -36° | 220/77 -42° | ||
| PIH | used from 148 nm out; 104 nm from the line | L/V | 240/13 1° | 240/15 -3° | 210/42 -15° | 200/70 -25° | 220/74 -29° | 220/71 -36° | 220/62 -43° | |
| LND | used from 198 nm out; 70 nm from the line | 200/23 6° | 220/31 1° | 220/39 -11° | 230/39 -23° | 220/51 -28° | 220/66 -37° | 230/68 -45° | ||
| RKS | used from 247 nm out; 58 nm from the line | 200/41 | 220/44 1° | 220/35 -11° | 220/46 -24° | 210/53 -27° | 220/62 -35° | 230/61 -44° | ||
| GJT | used from 395 nm out; 54 nm from the line | 210/43 7° | 230/45 1° | 220/49 -12° | 220/62 -22° | 220/59 -28° | 230/60 -33° | 220/55 -45° |
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 |
|---|---|---|---|---|---|---|---|
| HLN Helena, MT | departure | VFR Sky: a few clouds at 2,100 feet, overcast at 5,000 feet | from the west (270°) at 8 knots | 10+ mi | 5,000 ft | 3,877 ft | 11:53 pm MDT (05:53 UTC) |
| BZN Bozeman, MT | 59 nm out, 16 nm east of the line, tower | low IFR Sky: overcast at 200 feet Weather: light snow, mist | from the west (270°) at 5 knots | 2.5 mi | 200 ft | 4,473 ft | 05:56 UTC |
| WYS West Yellowstone, MT | 119 nm out, 5 nm southwest of the line | low IFR Sky: a broken layer at 400 feet, overcast at 900 feet Weather: mist, unknown precipitation | from the west (260°) at 3 knots | 2 mi | 400 ft | 6,649 ft | 05:55 UTC |
| JAC Jackson, WY | 188 nm out, 10 nm west of the line, tower | VFR Sky: overcast at 5,500 feet | from the southwest (230°) at 5 knots | 10+ mi | 5,500 ft | 6,451 ft | 05:56 UTC |
| BPI Big Piney, WY | 257 nm out, 5 nm west of the line | VFR Sky: a broken layer at 7,500 feet, overcast at 9,000 feet | calm | 10+ mi | 7,500 ft | 6,993 ft | 05:53 UTC |
| RKS Rock Springs, WY | 326 nm out, 22 nm east of the line | marginal VFR Sky: a broken layer at 1,700 feet, overcast at 2,400 feet Weather: light rain | from the west-southwest (250°) at 11 knots | 10+ mi | 1,700 ft | 6,764 ft | 05:54 UTC |
| VEL Vernal, UT | 385 nm out, 19 nm west of the line | VFR Sky: overcast at 6,000 feet | from the south-southeast (160°) at 6 knots | 10+ mi | 6,000 ft | 5,274 ft | 05:53 UTC |
| GJT Grand Junction, CO | destination | VFR Sky: a few clouds at 6,000 feet, overcast at 10,000 feet | variable at 4 knots | 10+ mi | 10,000 ft | 4,861 ft | 11:53 pm MDT (05:53 UTC) |
The highest airport on this list sits at 6,993 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At GJT when you get there the forecast at the estimated arrival, 4:41 am MDT (10:41 UTC)
Wind from the south at 18 knots, gusting to 27, visibility more than 6 miles, scattered clouds at 3,500 feet, a broken layer at 7,000 feet VFR
30% chance between Mon 2:00 am MDT (08:00 UTC) and 8:00 am MDT (14:00 UTC): visibility 4 miles, light rain showers, a broken layer at 3,500 feet marginal VFR
The whole forecast for GJT
- From Mon 12:00 am MDT (06:00 UTC): wind from the north at 8 knots, visibility more than 6 miles, showers nearby, scattered clouds at 7,000 feet, a broken layer at 10,000 feet
- From Mon 2:00 am MDT (08:00 UTC): wind from the south at 18 knots, gusting to 27, visibility more than 6 miles, scattered clouds at 3,500 feet, a broken layer at 7,000 feet
- 30% chance between Mon 2:00 am MDT (08:00 UTC) and 8:00 am MDT (14:00 UTC): visibility 4 miles, light rain showers, a broken layer at 3,500 feet
- From Mon 8:00 am MDT (14:00 UTC): wind from the south-southeast at 19 knots, gusting to 31, visibility more than 6 miles, scattered clouds at 4,500 feet, a broken layer at 7,000 feet
- 30% chance between Mon 8:00 am MDT (14:00 UTC) and 12:00 pm MDT (18:00 UTC): visibility 4 miles, light rain showers, a broken layer at 3,500 feet
- From Mon 12:00 pm MDT (18:00 UTC): wind from the south-southwest at 16 knots, gusting to 24, visibility more than 6 miles, scattered clouds at 4,000 feet, a broken layer at 6,000 feet
- 30% chance between Mon 12:00 pm MDT (18:00 UTC) and 6:00 pm MDT (00:00 UTC): visibility 4 miles, light rain showers, a broken layer at 4,000 feet, a broken layer at 6,000 feet
- From Mon 6:00 pm MDT (00:00 UTC): wind from the west at 12 knots, gusting to 21, visibility more than 6 miles, a few clouds at 6,000 feet, scattered clouds at 8,000 feet
- 30% chance between Mon 6:00 pm MDT (00:00 UTC) and 12:00 am MDT (06:00 UTC): visibility 4 miles, light thunderstorms with rain, a broken layer at 6,000 feet (thunderheads)
The forecast for HLN, the departure
- From Mon 12:00 am MDT (06:00 UTC): wind from the west-northwest at 14 knots, visibility 3 miles, light snow, overcast at 3,500 feet
- At times between Mon 12:00 am MDT (06:00 UTC) and 3:00 am MDT (09:00 UTC): visibility 1 mile, light snow, overcast at 1,500 feet
- From Mon 3:00 am MDT (09:00 UTC): wind light and variable, visibility more than 6 miles, overcast at 1,500 feet
- 30% chance between Mon 3:00 am MDT (09:00 UTC) and 6:00 am MDT (12:00 UTC): visibility 3 miles, light snow, overcast at 1,000 feet
- From Mon 3:00 pm MDT (21:00 UTC): wind light and variable, visibility more than 6 miles, scattered clouds at 1,500 feet, scattered clouds at 3,500 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 HLN 6:45 pm MDT (00:45 UTC), at GJT 6:38 pm MDT (00:38 UTC) (civil twilight ends 7:05 pm MDT (01:05 UTC)). At 120 knots the arrival at GJT is before sunrise there (7:20 am MDT (13:20 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: Helena Regional, Grand Junction Regional.
