I thought it'd be fun to stat out some spells that Jadis, The White Witch, from the Chronicles of Narnia probably would have in her grimoire. Without further ado:
Charm of Perpetual Winter, or "Always winter, and Never Christmas"
Target: Boundary, Duration: Year, Range: Touch; Ritual
This spell causes a region to be cast in perpetual winter for a year. The area within the bounds of this spell is constantly chilled, and even fires and other sources of warmth within the boundary are dimmed. Additionally, the region is subjected to regular snowfall so that is covered in a perpetual blanket of snow.
Base 4, +4 boundary, +4 year, +1 touch, +1 Creo, +1 Auram = Pe(Cr)Ig(Au) 55
Invoke the Endless Snowfall
Target: Boundary, Duration: Year, Range: Sight; Ritual
The maga conjures a bank of clouds over a region so that for an entire year, it blankets the region in snow. This snow will only persist if the region below is also cold.
base 2, +4 boundary, +4 year, +3 sight = CrAu 45
Curse of Medusa, or "Fate of Mr. Tumnus"
Target: Individual, Duration: Sun, Range: Touch
The maga touches her wand to a living person or animal and it instantly is turned into stone. Breaking the stone statue will cause grievous wounds and potentially death once the effect ends.
base 25, +2 sun, +1 touch = MuCo(Te) 40
The Deplorable Word
Target: Boundary, Duration: Momentary, Range: Touch; Ritual
The maga speaks a word, so terrible that every living thing within a boundary is instantly killed. The spell causes all life within its range to instantly wither, die, and become dust.
base 30, +4 boundary, +1 touch, +1 Herbam, +1 Animal = PeCo(He)(An) 65