「雪が大分溶けてきた」は次のように表現できます。
ーA lot of the snow has begun melting.
ーMost of the snow has started to disappear.
ーMost of the snow has started melting.
to melt で「溶ける」
to disappear で「なくなる・姿を消す」
例:
Now that March has begun, most of the snow has started melting.
「3月になり、雪が大分溶けてきました」
ご参考まで!