Le Grand Mont
📍 Rhone-Alpes , Departement de la Savoie · Nearest city: La Bathie (7 km)
63 XC score / 100 · takeoff at 2652 m · 📍 View on map
Coordinates and external links
45.63210, 6.53710Forecast next days
Updated: 2026-04-20 12:31 UTC · Source: Open-Meteo · Thermal window 10:00–18:00 local time
Día volable, condiciones decentes, base de cúmulos ~1054 m, viento 11 km/h.
base ~1054m · wind 11 km/hDía volable, condiciones decentes, base de cúmulos ~1006 m, viento 15 km/h.
base ~1006m · wind 15 km/hDía muy favorable para XC, base de cúmulos ~1716 m, viento 13 km/h.
base ~1716m · wind 13 km/hDía volable, condiciones decentes, base de cúmulos ~1115 m, viento 8 km/h.
base ~1115m · wind 8 km/hComposite flyability score (CAPE + LI + wind + precip + low clouds). Cross-check with local pilots before flying.
Detailed hourly weather
2026-04-20⚠️ Marginal · peak 55 at 16h
- Cloud suck alto (100/100) — base bajo freezing con CU
| 08 50 ☁️⚠️ | 09 50 ☁️⚠️ | 10 50 ☁️⚠️ | 11 50 ☁️⚠️ | 12 50 ☁️⚠️ | 13 50 ☁️⚠️ | 14 50 ☁️⚠️ | 15 50 ☁️⚠️ | 16 55 ☁️⚠️ | 17 50 ☁️⚠️ | 18 40 ☁️⚠️ | 19 55 ☁️⚠️ | 20 50 ☁️⚠️ |
Peak 16h: CAPE 0 J/kg · LI 0.9 · BL top 1730 m · w* 0.0 m/s · cloud base 3439 m · 0°C at 2640 m · Pro score 78/100 · sun 24° over slope
2026-04-21❌ Not recommended · peak 60 at 15h
- Día muy estable (CAPE<50, LI>2) — sin térmicas
- Cloud suck alto (88/100) — base bajo freezing con CU
| 08 30 ☁️⚠️ | 09 30 ☁️⚠️ | 10 50 ☁️⚠️ | 11 50 ☁️⚠️ | 12 55 ☁️⚠️ | 13 55 ☁️⚠️ | 14 50 ☁️⚠️ | 15 60 ☁️⚠️ | 16 55 ☁️⚠️ | 17 55 ☁️⚠️ | 18 50 ☁️⚠️ | 19 55 ☁️⚠️ | 20 30 ☁️⚠️ |
Peak 15h: CAPE 10 J/kg · LI 3.4 · BL top 1800 m · w* 0.0 m/s · cloud base 3714 m · 0°C at 1990 m · Pro score 73/100 · sun 31° over slope
Hourly flyability (0–100). ⛈️ = storm risk · ☁️⚠️ = cloud suck · 🏔️ = active ridge lift. CAPE = convective energy, LI = stability, BL top = thermal ceiling, w* = estimated dry thermal velocity. Source: Open-Meteo (ECMWF/GFS/ICON blend model).
Estimated vertical profile (Sounding)
Reference time: 16:00 (peak of the day)
Surface T: 2.6°C · Td: -3.7°C
LCL (cloud base): 787 m
BL top: 1730 m
0°C level: 2640 m
Approximate profile from surface variables + synoptic levels. Red lines = temperature, dashed blue = dew point. Orange bands = detected inversions.
Wind chart — altitude × time
Color: green < 20 km/h · yellow 20-30 · red >40. Arrows point to where the wind is blowing. Each column = 1 hour. 4 altitudes: 10m surface, 80m first thermal, 1500m (850 hPa) thermal cruise, 3000m (700 hPa) top.
Wind next days (Open-Meteo model)
Wind rose 10m — 2026-04-20
| Date | Morning 08-12h | Midday 12-16h | Evening 16-20h | |||
|---|---|---|---|---|---|---|
| 2026-04-20 | 6 km/h W | gust 20 | 10 km/h W | gust 22 | 9 km/h NW | gust 26 |
| 2026-04-21 | 2 km/h W | gust 19 | 9 km/h W | gust 25 | 10 km/h W | gust 29 |
Colors: green < 15 km/h (optimal) · orange 15-25 · red >25 (flying not recommended). ⚠️ = shear >25 km/h between 10m and 850 hPa (potentially broken thermals).
Takeoff orientations
Green = good orientation · Yellow = possible · Gray = not suitable
Why this site has thermal potential
| Factor | Value | Interpretation |
|---|---|---|
| Hotspot density (5 km) | 5 | Medium |
| Avg thermal probability | 0.80 | Based on thousands of aggregated IGC flights |
| Solar orientation | 0.62 | Slope faces south in northern hemisphere |
| Own flight history | 0.00 | Thermals detected in platform IGC tracks |
Takeoff description
summit montain, grass slope.
Pilot comments
small report here: http://www.vol-nature.fr/blog/vol-montagne-beaufortain/
Nearby sites
Fenetre 7 (46) · Naves (lac des bozons) (51) · Roche parstir (47) · Montgirod-Arcachat (69) · Pra Plan (45) · Bisanne Sud (66)