Mid-September Tasman System
1 resort in the path, 32cm at the biggest. Watching — the models see it but do not yet agree closely.
+32CM
Predicted at Mt Olympus
Storm
Sep 18–20
1 resort in the path
Peak
Sep 18
24cm at Mt Olympus
Predicted
32cm
Mt Olympus
Confidence
Watching
Updated
Sep 9, 18:30 UTC
SnowSure Forecaster
Written from the blend and the model spread · updated Sep 9, 18:30 UTC
A storm watch has been issued for the Mid-September Tasman System, expected to impact the region from September 18 to September 20, 2026. This Pacific system is projected to deliver 32.3 cm of snow to Mt Olympus, with the largest single-day accumulation reaching 24.3 cm, supported by agreement among three models. Other resorts may not see significant snowfall during this event, as the focus of the storm appears to be concentrated on Mt Olympus. If model agreement tightens or the storm window shifts, it could alter the snowfall predictions and potentially affect other resorts in the area.
Snow by day
Sep 17 – Sep 21, 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.
Mt Olympusbase 1,430 m · summit 1,880 m
—cm snow
no daily data
No daily series on file for these resorts yet.
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 2026-09-09 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 2026-09-09 with 32cm forecast at Mt Olympus.
