Typical operating window
December–AprilAtlantic and northwesterly storms commonly establish the winter base from December into January.Verified planning context
Snow, weather and avalanche context
Historical patterns help you compare trips. They do not predict your week or replace the operator's daily decisions.
Strongest comparable snow evidence
406 mm SWE median · 340–442 mm interquartile rangeVielha gateway ERA5-Land grid cellTier C · modelled estimate · low confidenceSnow character
transitionalThe north-facing Atlantic side can hold soft snow; wind, sun, and warm intrusions create strong aspect differences.Public avalanche information
Centre de Lauegi Val d’Aran bulletinUse the original bulletin for subregion, elevation, aspect, issue time, and validity.Weather and flight context
Atlantic moisture meets Pyrenean terrain, with sharp changes across passes, elevation, and aspect.
- Orographic cloud
- Ridge wind and lee loading
- Rapid snowline changes
Meteorological reference area
Val d’Aran
- Includes
- Val d’Aran mountain and forecast region.
- Excludes
- The wider Pyrenees outside Val d’Aran.
- Elevation
- No verified operator-terrain elevation band is public. Each evidence value retains its site elevation.
Evidence pack
Measurements, claims and gaps stay separate.
Tier CModelled snowfall water equivalent406 mm SWE median · 340–442 mm interquartile range
- Site
- Vielha gateway ERA5-Land grid cell · 42.7000, 0.8000 · 0.4 km from Vielha gateway reference point
- Period
- Calendar years 1991–2020
- Completeness
- 360 monthly means; all 30 calendar years contain 12 values.
- Method
- ERA5-Land monthly mean daily snowfall accumulation was multiplied by calendar days and 1,000, then summed by calendar year.
- Limitation
- This reference area supports evidence discovery and comparison. It is not an operating-area or tenure boundary. The sampled gateway cell can differ substantially from ski elevations. This unadjusted 0.1° reanalysis grid cell is not an observation, snow depth, or terrain-wide total. Grid elevation and wind redistribution can cause substantial local bias.
- ERA5-Land monthly averaged data from 1950 to presentCopernicus Climate Change Service · accessed 2026-08-26
Monthly evidence
Each cell keeps its measurement type and unit. Reanalysis water equivalent is not snow depth. Text-only cells preserve a representative data gap.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 80.4 mm SWE | 56.9 mm SWE | 59.8 mm SWE | 64.3 mm SWE | 11.9 mm SWE | 0 mm SWE | 0 mm SWE | 0 mm SWE | 0 mm SWE | 5.3 mm SWE | 46.1 mm SWE | 59.6 mm SWE |
Commercial operator assessment
Operator assessment process not independently verifiedThe operator must assess current snow, avalanche terrain, weather, aircraft limits, and rescue options. No private operational plan is inferred.
Sources and evidence notes
- WMO Climatological NormalsWorld Meteorological Organization · accessed 2026-08-25
- ERA5-Land hourly data from 1950 to presentCopernicus Climate Change Service · accessed 2026-08-25
- Centre de LauegiConselh Generau d’Aran · accessed 2026-08-25
- Published operator and trip inventoryHeliski International editorial team · accessed 2026-08-25
- ERA5-Land monthly averaged data from 1950 to presentCopernicus Climate Change Service · accessed 2026-08-26
- Val d’Aran heliski season FAQGuide Val d’Aran · accessed 2026-08-25