State Highway 94 is shut between Hollyford Road Junction and Donne River.
Natural avalanches are crossing the road, the Milford Road Alliance advised this morning.
Assessment and avalanche mitigation works will be carried out when conditions allow to reduce hazard, potentially tomorrow, it said.
Volatile weather over the next few days could bring further disruptions, increased avalanche hazard and road closures.
Forecast for Homer Tunnel area
Today: Cloudy, with a few showers turning to rain this afternoon.
Tuesday: Rain and snow to 700m, clearing in the afternoon.
Wednesday: Showers and possible snow.
Thursday: Heavy rain turning to snow.
Friday: Snow showers clearing.