The witch recites the spell and violently shakes the bowl with the rainwater until there's nothing left inside. Once the bowl is empty, the spell takes effect and a strong storm will begin forming unnaturally fast. It doesn't matter what weather there was before, it'll become overcast, windy and rainy within half an hour and stay that way for four hours. Everyone who is outside in the storm suffers a +6 difficulty modifier to every check due to the wind, rain and thunder.