Understanding Melancholy in Context

During the long winter months, Ella found herself feeling unusually melancholy. The continuous snowfall and the biting cold filled her with a sense of sadness and longing. To lift her spirits, she decided to visit her cousin who lived in a warmer region. Ella hoped that a change in scenery would help her overcome her feeling of gloom.

What does the word melancholy most likely mean in this context?