Forecasters have warned Tayside to prepare for three days of heavy snowfall.
A Met Office office amber warning will now come into effect at 3pm on Thursday and remain in place until 6am on Saturday morning. It was previously due to be in force from midnight on Friday.
Up to 20in of snow could batter the highest regions of Tayside with as much as 6in possible even to low levels. Only coastal communities are expected to miss out on the worst of the weather.
Forecasters say the wintry showers will be “widespread, persistent and heavy”, enduring from Thursday right through until Saturday morning.
The Met Office also said blizzard conditions are possible in some areas, adding that the weather could potentially lead to communities being cut off, travel disruption and road closures.
Angus and Perthshire both fall within the amber warning zone.
It comes after the Highland Main Line was closed on Thursday due to drifting snow.
The amber snow warning reads: “Snow is expected to become more widespread, persistent and heavy from Thursday afternoon and continue through to Saturday.
“Fresh snowfall totals of 10-15cm (3.9-5.9in) is possible at low-levels, with 20-30cm (7.9-11.8in) accumulating above about 150m (492ft).
“Some high ground exposed to strong easterly winds could see as much as 50cm (19.7in) building up by Saturday morning.
“However some places close to the east coast may see only small amounts of snow settling.
“The strong easterly winds will likely lead to drifting snow, temporary blizzard conditions, and ice forming on exposed power lines and phone masts. Persistent snow should ease on Saturday, though snow showers will follow.”
Weather alerts have been in place across the local area every day since Monday.
Three more severe weather warnings
A yellow Met Office snow warning is also in place across almost all of Tayside and Fife until noon on Saturday.
Another also highlighting a risk of ice comes into force immediately afterwards and will endure until midnight on Sunday. It will cover all of the local area.
A further snow and ice warning will be in place throughout all of Monday.