Thunderstorm

The combined effects of precipitation and wind reduce visibility by three quarters, imposing a -8 penalty on perception checks. Thunderstorms make ranged weapon attacks impossible, except for those using siege weapons, which suffer a -4 penalty on attack rolls.
Thunderstorms automatically extinguish candles, torches, and similar unprotected flames. They cause protected flames, such as those of lanterns, to dance wildly and have a 50% chance to extinguish these lights.
Creatures must succeed on a DC 15 Strength save or be blown away (Tiny or smaller creatures; knocked prone and rolled 1d4 x 10 feet, taking 1d4 points of nonlethal damage per 10 feet), knocked down (Small; prone), or checked (Medium; unable to move forward against the force of the wind).
Airborne creatures are instead blown back 2d6 x 10 feet and dealt 2d6 points of nonlethal damage due to battering and buffeting (Small or smaller creatures), blown back 1d6 x 10 feet (Medium), or blown back 1d6 x 5 feet (Large).
In addition, thunderstorms are accompanied by lightning that can pose a hazard to characters without proper shelter (especially those in metal armor). As a rule of thumb, assume one bolt per minute for a 1 hour period at the center of the storm. Each bolt causes electricity damage equal to 1d10d8.

Type

Natural