Lotte Arai JP
The short answer: PassCast projects a median of 472" at Lotte Arai for 2026-27 — 91% of a typical season — with a skiability rating of 72/100, ~31 powder days, and Dec–Jan as the prime window. Updated daily from 10,000 simulations.
80% of simulated seasons land between 311" and 727". Reseeded daily as ENSO observations, CPC outlooks, and SEAS5 runs update.
10,000 simulated 2026-27 seasonsENSO-weighted resampling of 36 real seasons (1990–2026) at Lotte Arai, tilted by the live seasonal outlook
Highlighted bars span the middle half of outcomes (P25–P75). The yellow dashed line is a typical season — the median of the last 36 at this mountain.
What's driving this forecast
The 2026-27 season is simulated by resampling Lotte Arai's historical seasons weighted toward El Niño analog years. NOAA CPC El Niño Advisory (June 11, 2026): El Niño conditions are present and expected to strengthen into winter 2026-27, with a 63% chance of a very strong event (Niño3.4 ≥ +2.0°C) during Nov-Jan. CPC DJF strength odds: very strong 46%, strong 33%, moderate 16%. IRI (June 22) concurs at 98% El Niño for DJF. Latest observed ONI (AMJ 2026): +1.0.
El Niño weakens the East Asian Winter Monsoon — fewer Siberian cold surges across the warm Sea of Japan means fewer sea-effect powder days (Ueda et al. 2015). El Niño seasons average ~6% less snowfall nationally, but 1997-98 and 2015-16 cut low-elevation Honshu to near half of normal; Hokkaido and high terrain are most resilient. Applied as a -4% tilt at partial weight.
Day-to-day weather models have no skill this far out, so the near-term forecast contributes 0% weight today. The simulation leans entirely on ENSO-conditioned climatology — exactly what an honest seasonal outlook should do in summer. Weighting shifts toward live forecasts as opening day approaches.
The regional readJapan · from the 2026-27 outlook
A strong El Niño weakens the East Asian Winter Monsoon, and fewer Siberian cold surges across the Sea of Japan means fewer of the sea-effect powder days that make Japanuary. The strong-event analogs matter: 1997-98 and 2015-16 were two of Japan's leanest, latest-starting winters, with some low Honshu resorts near half of normal; 2023-24 began painfully late before February rescued Hokkaido. Expect a delayed start, rain events at low-elevation Honshu areas, and the best resilience in Hokkaido (Niseko, Rusutsu) and high-altitude Honshu. Aim for mid-January to mid-February — unless the Arctic Oscillation goes strongly negative, the one wildcard that can override El Niño entirely.
Month by monthENSO-conditioned analog medians vs a typical month — when this season should deliver
Prime window: Dec–Jan — the deepest contiguous stretch of the conditioned season. Aim the trip there.
The analog poolEvery season since 1990 at Lotte Arai (ERA5, calibrated to the resort's reported average), colored by ENSO phase
Pass math for Lotte Arai
Verdicts run the full simulated snow distribution through breakeven math at ~$68/day window prices. Add trip legs on the home page to compare passes across your whole season.
- Covers Lotte Arai (5d).
- Snow-adjusted across the simulated seasons, expect ~9.7 covered days; the pass beats window tickets in 0% of 10,000 simulated seasons (mean shortfall $679).
- At this plan, window tickets or a cheaper product wins.
- Covers Lotte Arai (7d).
- Snow-adjusted across the simulated seasons, expect ~9.7 covered days; the pass beats window tickets in 0% of 10,000 simulated seasons (mean shortfall $973).
- At this plan, window tickets or a cheaper product wins.
Lotte Arai 2026-27: straight answers
- How much snow will Lotte Arai get in the 2026-27 season?
- PassCast's latest 10,000-run simulation (reseeded 2026-07-10) puts the median at 472 inches — 91% of a typical season at Lotte Arai — with 80% of outcomes between 311 and 727 inches. The forecast blends Lotte Arai's own 36-season ENSO analog record with NOAA's seasonal outlook and the ECMWF SEAS5 ensemble.
- Is a season pass worth it for Lotte Arai in 2026-27?
- Lotte Arai is on Ikon Pass, Ikon Base for 2026-27, but with day caps at this mountain the pass only pays off combined with days at its other resorts — the simulator on this page runs that math for your plan.
- When is the best time to ski Lotte Arai in 2026-27?
- Dec–Jan is the prime window — the deepest contiguous stretch of the ENSO-conditioned season at Lotte Arai. Month-by-month medians are charted on this page.
- How reliable will the snow be at Lotte Arai this season?
- The simulation gives Lotte Arai a 38% chance of beating its typical season and a median of about 31 six-inch-plus powder days. Its skiability rating is 72/100 (“Deep & reliable”), updated daily.
Sources: ERA5 reanalysis & multi-model forecasts via Open-Meteo · NOAA CPC ONI, ENSO advisory & seasonal outlook · ECMWF SEAS5 · pass prices verified July 2026. See methodology for the honest fine print.