By casting this spell, the wizard causes a horrendous thunderstorm to break in any vicinity he so chooses. After the casting of the spell, it takes one turn for the clouds to gather, regardless of the current weather conditions. Another turn after this, the storm breaks, rain pounds down, and lightning bolts strike all over the area of effect at random. The caster must concentrate for the entire duration; any disturbance during this time negates the storm, causing the rain to cease and the clouds to disperse in one turn. The rains fall at the rate of 14-inch per hour. The wizard can direct one lightning bolt every five rounds, at the cost of shortening the spell's duration by one hour each. The caster can direct only as many lightning bolts (directed bolts are treated as the 3rd-level spell, lightning bolt) as he has levels minus two. Thus, a 20th-level wizard can direct a total of eighteen bolts, shortening the spell's duration to only two hours (at one bolt every five rounds, it would take a minimum of one and a half hours to direct all eighteen lightning bolts.)
A bolt cannot be directed by the wizard if doing so would negate the hour of duration in which the attempt is made. For instance, if a 16th-level wizard cast a storm spell and let it rage for fifteen hours without directing any bolts, he could not direct one in the last hour of the spell as that bolt would negate the hour of the spell that was already taking place. These bolts cause 6d6 points of damage (save vs. spell for half damage) and strike in a 5-foot diameter column.
This spell can be cast through a crystal ball.
The material component of this spell is a used (previously stricken) lightning rod, which the caster hurls at the sky to cause the clouds to gather. The rod flies straight up into the clouds, where it is consumed in a brilliant lightning flash.
Notes: Common for Storm mages, uncommon for Weather mages; otherwise, very rare. Believed to be in The Blue Book of Othyisar Du'Morde, Vol. III. (Updated from Dragon Magazine.)