"Avalanches have formed weak layers in steep slopes. The safest thing is to avoid the steep slopes until the snow has become more stable", writes the Environmental Protection Agency about the situation in southern Jämtland Mountains, which includes the popular ski resort Åre.
In western Vindelfjällen, it is recommended to avoid slopes with a slope angle over 30 degrees that have fresh avalanche snow.
"On steep slopes that have accumulated avalanche snow over the past few days, a person can trigger large avalanches", writes the authority.
The forecast for the two areas applies until 6 pm on New Year's Eve. Significant avalanche danger means a three on the five-point avalanche scale.
In western Härjedalsfjällen and southern Lapland Mountains, there is moderate avalanche danger, a two on the same scale, until 6 pm on New Year's Eve.