NZ Transport Agency/Waka Kotahi said State Highway 94 was closed from Saturday night and there were avalanches on Sunday.
The agency also artificially released snow on Monday.
The highway is closing from East Gate (Hollyford) to Donne River (Westgate) at 5pm today as a significant storm was forecast to hit the area and expected to elevate the avalanche hazard, Milford Road Alliance advised this morning.
The road was likely to reopen early on Thursday afternoon, however road restrictions or an overnight closure was likely for Thursday night as snowfall was forecast to low levels, it said.
Forecast for Homer Tunnel area
Today: Cloud increasing. Showers in the afternoon, turning to heavy rain overnight. North-west winds strengthening.
Thursday: Heavy rain turning to snow.
Friday: Snow showers easing.
Saturday: Cloudy and showers.
Sunday: Cloudy and showers.