Late-September Andes System
1 resort in the path, 95cm at the biggest. Likely — the models agree on this one.
+95CM
Predicted at Corralco
40–198cm across the models
Storm
Sep 23–27
1 resort in the path
Peak
Sep 24
56cm at Nevados de Chillán
Predicted
95cm
Corralco · 40–198cm across the models
Confidence
Likely
Updated
Sep 21, 18:30 UTC
SnowSure Forecaster
Written from the blend and the model spread · updated Sep 21, 18:30 UTC
Current prediction: 40–198cm for Nevados de Chillán between 2026-09-23 and 2026-09-27, 95cm our central figure. The biggest day is 2026-09-24 at 56cm. Nevados de Chillán is the only resort clearing our threshold so far. Confidence is likely: the models agree on both the window and the magnitude. On day one we said 120cm for Nevados de Chillán; that is the number we are measured against. These figures are re-read from the latest model blend; each entry in the log keeps what we said at the time.
Forecast log
Every entry, newest first. Nothing is overwritten.
- Day 10·Sep 21·Likely·73cm(-53)
Late-September Andes System: 72.8cm for Corralco (47.2–123cm)
Day 10: the window start moved one day later, and totals are down 53cm since the previous entry. The forecast window is now set for 2026-09-24 to 2026-09-26, with Corralco expected to receive 72.8cm, Las Leñas 41.7cm, and Batea Mahuida 38cm. The biggest day for all resorts is projected for September 24, with Corralco leading at 59.8cm. Confidence remains likely at two of the three resorts, while we are watching Batea Mahuida closely as its trend is new.
Window Sep 24–26 · Corralco
- Day 9·Sep 20·Likely·126cmFirst prediction
Late-September Andes System: 125.8cm for Corralco (45.7–205.8cm)
The prediction for the late-September Andes System, from September 23 to September 27, indicates significant snowfall totals, with Corralco leading at 125.8cm (range 45.7–205.8cm). The overall pattern suggests a favorable setup for snow accumulation across the region. Corralco and Nevados de Chillán are likely to see the most substantial totals, while Cerro Catedral and Las Leñas also stand to benefit. However, Las Araucarias, Cerro Perito Moreno, and Batea Mahuida are currently in a watching phase, with potential for improvement. A shift in the storm's trajectory or intensity could alter these predictions.
Window Sep 23–27 · Corralco
Snow by day
Sep 22 – Sep 28, with a day either side. For each resort: where the freeze line sits against the mountain, then what falls — snow in cm, rain in mm — and the day read from those two numbers.
Nevados de Chillánbase 1,600 m · summit 2,499 m
95cm snow25mm rain
Modelled at the summit, 2,499 m · snow to the base
linem
/ raincm · mm
Tue
Sep 22
Dry
Wed
Sep 23
Mixed
Thu
Sep 24
Snow
Fri
Sep 25
Mixed
Sat
Sep 26
Mixed
Sun
Sep 27
Snow
Mon
Sep 28
Snow
snow Thu, Sun · rain low, snow high Wed, Fri, Sat
snowrain low, snow highraindryThe dots are the freeze line — the height where rain turns to snow. Solid: straight from the models. Hollow: estimated from temperature. Above the summit line it rains on the whole mountain; below the base line it snows all the way down. Blue bars are snow in cm, amber bars rain in mm; the totals above are their sums.
Rain / snow line
Base to summit for each mountain, with the snow line cut across them.
The system
700mb flow — where the storm is, and what is steering it. Pins sized by forecast total.
72-hour snowfall forecast for the same window.
In the path
Forecast, not observation — none of this has fallen yet. Totals are across the window. We will post what fell when the window closes.
Last updated 2026-09-20 18:30 UTC. SnowSure scans a blend of seven weather models twice daily and flags systems clearing 30cm over 72 hours, three to fourteen days out. This watch opened on 2026-09-12 with 30cm forecast at Nevados de Chillán.
