Summon rain [824]
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Usage:  USE 824 <aura> ["Name of storm"]

Required aura:  three or more points
Time to cast:   seven days

Summon a rain weather entity.  Rain storms may be summoned from
forest or ocean provinces.  Once a location has produced a rain
storm, another rain storm may not be summoned from that place
until the first storm has dissipated.

The storm will have a strength of twice the amount of aura invested
in its summoning.  Storms lose one point of strength at the end of
each month.  When a storm's strength reaches zero, it dissipates.

While the storm exists, the summoner will get a location report
for the storm's province.