This spell allows the caster to summon weather that is either appropriate or inappropriate to the climate and season of the region. The summoned effects are always dramatic—cool breezes or light fog will not appear. Instead, torrential floods will assault a desert, a heat wave will rage in polar wastelands, and tornadoes and hurricanes will rip across gentle landscapes. A blizzard might spring up in summer or a tornado might materialize in the winter.
The spellcaster has no influence over the weather pattern that emerges. He cannot control the area of effect or the duration of the weather.
Four turns after the spell is cast, the trend of the weather will become apparent—a sudden chill, gust of wind, overcast sky, etc. The uncontrolled weather arrives on the fifth turn. Once the weather has arrived, it cannot be dispelled. If the spell is canceled by the caster before the beginning of the fifth turn, the weather slowly reverts to its original condition.
The effects of the spell are the decision of the DM. The effects should be grand and impressive. Following are suggested effects of the weather.
Torrential Rain/Blizzard: Visibility is reduced to 100 yards or less; travel is nearly impossible due to water or heavy snow on the ground.
Storm/Hurricanes: All flying creatures are driven from the skies; trees are uprooted; roofs are torn off; ships are endangered.
Heat Wave: Intense heat immediately causes ice bridges to melt; avalanches of snow and ice roll down mountains.
The DM determines the area of effect randomly. The maximum duration of the spell is one turn per level of the caster; however, the DM may cancel the effect after a shorter time.
Notes: Common for priests with major access to the sphere of Chaos (ToM).