Early-November Japan Sea System
1 resort in the path, 21cm at the biggest. Likely — the models agree on this one.
+21CM
Predicted at Kiroro
7–45cm across the models
Storm
Nov 6–9
1 resort in the path
Peak
Nov 7
10cm at Kiroro
Predicted
21cm
Kiroro · 7–45cm across the models
Confidence
Likely
Updated
Oct 30, 18:30 UTC
SnowSure Forecaster
Written from the blend and the model spread · updated Oct 30, 18:30 UTC
Current prediction: 7–45cm for Kiroro between 2026-11-06 and 2026-11-09, 21cm our central figure. The biggest day is 2026-11-07 at 10cm. Kiroro 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 34cm for Kiroro; 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 2·Oct 30·Likely·32cm(-1)
Confidence rises: 14–51cm for Kiroro, 2026-11-06 to 2026-11-09
Day 2: the window has moved one day earlier, and totals have adjusted down slightly. We now expect 32cm for Kiroro over the window from 2026-11-06 to 2026-11-09, with a range of 14.3–51cm. The biggest day is projected to be 2026-11-07, with 18.1cm likely. Confidence has shifted from watching to likely, indicating a more stable forecast as models align on the event's timing and intensity. As we approach the window, we will continue to monitor any changes in model outputs and atmospheric conditions that could affect snowfall amounts. Pay attention to updates as we get closer to the event.
Window Nov 6–9 · Kiroro
- Day 1·Oct 29·Watching·34cmFirst prediction
Watch issued: 9–78cm for Kiroro, 2026-11-07 to 2026-11-09
THE PREDICTION: 9–78cm for Kiroro between 2026-11-07 and 2026-11-09, 34cm our central figure. The biggest day is 2026-11-08 at 14cm. Kiroro is the only resort clearing our threshold so far. We are watching a significant system for Japan, 9 days out. Confidence is watching: the signal has crossed our threshold but the models still disagree on how much. Resorts nearest the core of the moisture win; totals fall off away from it, and the lowest bases are the first to see rain mixed in. The prediction changes if model agreement loosens, the window slides later, or the freezing level trends higher. We will update this log every scan until the window opens.
Window Nov 7–9 · Kiroro
Snow by day
Nov 5 – Nov 10, 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.
Kirorobase 570 m · summit 1,180 m
21cm snow10mm rain
Modelled at the summit, 1,180 m · snow above 1,112 m
linem
/ raincm · mm
Thu
Nov 5
Rain
Fri
Nov 6
Mixed
Sat
Nov 7
Snow
Sun
Nov 8
Snow
Mon
Nov 9
Snow
Tue
Nov 10
Snow
snow Sat, Sun, Mon · rain low, snow high Fri (above about 1,112 m)
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 2026-10-30 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 2026-10-30 with 30cm forecast at Kiroro.
